Aart's Blog

Country Chess Netherlands, first division

2012-01-30T14:18:00.000-08:00

BikJump ended at 7th place in Geert Maeckelbergh's Country Chess First Divsion of The Netherlands. After a result like this, I feel the well-known "itch" to go back to work on my chess engine again. But first a few more improvements in Chess for Android.

In any case, thanks for running the tournament Geert.

Virutor Chess for Android

2012-01-30T11:55:00.000-08:00

Vaclav Vavra set up a new website for Virutor Chess, an UCI engine available for Windows, ARM-based Android devices (and Linux soon to follow). The Android version imports without any issues in Chess for Android. I also ran a quick tournament between the built-in engine, BikJump, and Virutor. The results are show below.

                         1    2     3

  1 BikJump              *   9.5  10.0   19.5/20

  2 Chess for Android   0.5   *    8.0    8.5/20

  3 Virutor Chess       0.0  2.0    *     2.0.20

Cheng3 for Android

2012-01-22T16:43:00.000-08:00

Another engine that can be imported in Chess for Android just became available. Martin Sedlák released a new version of his engine Cheng3, and Jim Ablett kindly made a binary available for ARM-based Android devices. The engine functions well, although it responds with "no GTB found" for the Gaviota endgame tablebases, even thought the cp4 versions reside in /sdcard/gtb.

The results of a quick tournament with different engines varying in strength is shown below. Quite impressive!

1 2 3 4 5
1 Stockfish 2.1 ********** 1111111111 1111111111 1111111101 1111111111 39.0/40
2 cheng3 1.07 JA 0000000000 ********** 10½0½100½1 11111½0111 1111111111 26.5/44
3 GarboChess3 0000000000 01½1½011½0 ********** 11110½½010 1111111111 21.5/40
4 Daydreamer 1.75 JA 0000000010 00000½1000 00001½½101 ********** 1½11111111 16.0/40
5 BikJump v2.1P 0000000000 0000000000 0000000000 0½00000000 ********** 1.0/44

Chess for Android 3.1.1

2012-01-17T10:30:00.000-08:00

I just released version 3.1.1 of Chess for Android at the Android market and as direct download with the new Setup Position feature.

Update: There was a minor bug in defining the halfmove clock of a position, something that is relevant only for positions affected by the fifty move rule. I have posted a fix in version 3.1.2 on my website (or you can wait for the next release through the market).

More About Setup Position

2012-01-15T18:58:00.000-08:00

I finished the new Setup Position feature, which I hope to release really soon. The board editor allows specifying a full FEN position, that is, a board position together with castling rights, the side-to-move, and possibly an en-passant file and halfmove clock counter (for the fifty-move rule). Touching a piece outside the board changes the "pen" to that piece. Alternative, touching a piece on the board changes the "pen" into that piece, and removes the piece from the board (useful to move pieces on the board to another position).

The landscape and portrait layouts are shown below.

Setup Position

2012-01-14T14:14:00.000-08:00

By popular demand, I am working on a Setup Position feature in Chess for Android (file, clipboard, and MIME type operations to import and export games are already supported).This new feature is still in prototype stage, but it is going to look something like shown below.

Viewing application/x-chess-pgn MIME type

2012-01-06T10:44:00.000-08:00

Starting with v3.1, Chess for Android registers itself as a viewer for the application/x-chess-pgn MIME type. This implies that when other Android applications request viewing a game in PGN format, Chess for Android, or any other chess program that supports this type, will open the game.

I am new to this mechanism, but the following two ways of viewing a game seem to work well. To request viewing a game in PGN format that resides in a file (with proper permissions, so that other applications can read it), simply use the following code sequence:

Intent intent = new Intent(Intent.ACTION_VIEW);
File file = ... file in pgn format ....;
intent.setDataAndType(Uri.fromFile(file), "application/x-chess-pgn");
startActivity(intent);

Alternatively, to view a game in PGN format that resides in a String, use the following code sequence (in this case, avoid confusing characters such as ':' in the String format):

Intent intent = new Intent(Intent.ACTION_VIEW);
String data = ".... game in pgn format ....";
intent.setDataAndType(Uri.parse(data), "application/x-chess-pgn");
startActivity(intent);

Although of course one could also set up an intent that invokes one particular chess application such as Chess for Android directly, this late-binding approach is more flexible since it eventually gives the user a choice what program capable of viewing PGN should be used.

Any input or suggestions for improvement welcome.

Chess for Android 3.1

2012-01-04T11:59:00.000-08:00

I just released version 3.1 of Chess for Android, available from the Android Market or as direct download. New features include:

engine pondering (UCI and XBoard)
fixed coach bug with move from/to a1
added application/x-chess-pgn MIME support

Critter 1.4 for Android

2011-12-28T19:09:00.000-08:00

Richard Vida released Critter 1.4, including a version for Android. This ARM binary imports well into Chess for Android. A quick 1-second-per-move tournament from both sides of all opening lines in the Nunn test suite on a Nexus S ended in favor of the previous version though.

DoubleCheck2.3 for Android

2011-12-21T19:35:00.000-08:00

Lucas Braesch released DoubleCheck 2.3 and I put an ARM binary on UCI and XBoard engines for Android (you can find another binary for ARM on Jim Ablett's website). Below, I show the results of a quick one-second-per-move tournament played from both sides of all lines in the Noomen test suite 2012 between some recent versions (32MB hash size, Nexus S).

1 2 3

1 DoubleCheck 2.3 * 36.5-23.5 39.5-20.5 76.0/120

2 DoubleCheck 2.0 23.5-36.5 * 35.5-24.5 59.0/120

3 DoubleCheck 1.3 20.5-39.5 24.5-35.5 * 45.0/120

TjChess for Android

2011-12-21T10:49:00.000-08:00

Another engine for ARM-based Android devices! Tony Hecker kindly made ARM binaries of Tjchess available as either an UCI engine or a XBoard engine. Both import well in Chess for Android. Some screenshots below. With so many new engines, is it time for yet another Android chess engine tournament?

Umko for Android

2011-12-21T10:19:00.000-08:00

The list of chess engines compiled for ARM-based Android devices keeps growing. Someone pointed me to Borko Boskovic's Umko engine.

I tested this UCI engine in Chess for Android, and it works well. Some screenshots below.

Android Engines Tournament: Group A

2011-12-17T18:48:00.000-08:00

Group A has finished a complete thirty seconds-per-move tournament in Chess for Android, played from both sides of all positions in the Nunn opening suite under the conditions described earlier.

Congratulations to Richard Vida for Critter's victory in this tournament!

All games can be downloaded from the tournament page.

This completes the Android tournament with longer time controls (although since many more engines are available now, perhaps another one is already necessary!).

1 2 3 4 5
1 Critter 1.2 32-bit * 11.5-8.5 9.5-10.5 15.0-5.0 11.5-8.5 47.5/80
2 Stockfish 2.1.1 JA 8.5-11.5 * 13.0-7.0 9.5-10.5 11.0-9.0 42.0/80
3 Komodo32 2.03 AB 10.5-9.5 7.0-13.0 * 13.0-7.0 11.5-8.5 42.0/80
4 RobboLito 0.085g3l 5.0-15.0 10.5-9.5 7.0-13.0 * 12.0-8.0 34.5/80
5 IvanHoe-Beta v999947c 8.5-11.5 9.0-11.0 8.5-11.5 8.0-12.0 * 34.0/80

Arasan for Android

2011-12-14T11:46:00.000-08:00

Jim Ablett kindly compiled Jon Dart's Arasan engine for ARM-based Android devices so that it can be imported in Chess for Android. The engine supports multithreading, Nalimov endgame tablebases, and clocked at about 100Kns out of the opening on my Nexus S.

Jim Ablett's Android Chess Engine Bundle Tested

2011-12-11T21:25:00.000-08:00

As posted earlier, Jim Ablett posted an Android Chess Engine Bundle, which various UCI and Win/XBoard engines that can be imported in Chess for Android. Because the Win/XBoard protocol feature is still relatively new in Chess for Android and conducted a test tournament between all the XBoard engines (except gfc-08-rev5-ja which often claims a mate without actually making the move; I am not sure if the standard allows this, but it seems weird that the GUI should verify the claim).

During this tournament I found a few opportunities for improving the GUI's handling of the protocol, which will be released soon. Also, the next release will add the much requested pondering feature (also called permanent brain).

Games available on request.

1 olithink-530-ja 34.5/38
2 crafty-234-ja 32.0/38
3 phalanx-xxii-ja 29.5/38
4 chess-one-201-ja 29.0/38
5 gullydeckel-215-pl10-ja 25.5/38
6 sloppy-023-ja 25.5/38
7 kmtchess-121-ja 23.0/38
8 surprise-43-b13-ja 23.0/38
9 scidlet-261b2-ja 21.0/38
10 gk-090-ja 19.5/38
11 natwarlal-014-ja 19.0/38
12 knightcap-36-ja 17.0/38
13 buzz-os-11-27-08-ja 17.0/38
14 sjeng-112-ja 16.0/38
15 mizar-30-ja 15.5/38
16 zzzzzz-351-ja 12.5/38
17 mskcp-145-ja 9.0/38
18 exchess-054-beta-ja 7.0/38
19 toledo-nanochess-2010-ja 2.5/38
20 Chess for Android 2.0/38

Android Engines Tournament: Group B

2011-12-04T14:58:00.000-08:00

Group B has finished a complete thirty seconds-per-move tournament in Chess for Android, played from both sides of all positions in the Nunn opening suite under the conditions described earlier. Regrettably I found that Crafty was put at a slight disadvantage (not something that would have changed the outcome though) due to a misinterpretation of XBoard's resign plus move command, causing a resign by illegal move in the next game. This issue has been fixed now.

Congratulations to IvanHoe for its promotion to Group A.

All games can be downloaded from the tournament page.

The games of the final group A have started!

1 2 3 4 5
1 IvanHoe-Beta 999947c * 15.0-5.0 17.0-3.0 19.0-1.0 19.0-1.0 70.0/80
2 scorpio 5.0-15.0 * 7.5-12.5 17.5-2.5 14.5-5.5 44.5/80
3 Toga II 1.4.1SE 3.0-17.0 12.5-7.5 * 12.0-8.0 13.0-7.0 40.5/80
4 crafty 1.0-19.0 2.5-17.5 8.0-12.0 * 12.0-8.0 23.5/80
5 GarboChess3 1.0-19.0 5.5-14.5 7.0-13.0 8.0-12.0 * 21.5/80

Jim Ablett's Android Chess Engine Bundle

2011-11-25T11:30:00.000-08:00

Jim Ablett very kindly posted an Android Chess Engine Bundle with various UCI and XBoard engines that can be imported in Chess for Android.

UCI:

daydreamer-175-ja  greko-82-ja    redqueen-098-ja  stockfish-211-ja

diablo-051b-ja     jazz-501-ja    rotor-04-ja      sungorus-14-ja

doublecheck-21-ja  komodo-13-ja   simplex-098-ja

garbochess-3-ja    pepito-159-ja  sissa-20-ja

XBOARD:

uzz-os-11-27-08          kmtchess-121-ja   scidlet-361-b2-ja
chess-one-201-ja         knightcap-36-ja   sjeng-112-ja
crafty-234-ja            mizar-030-ja      sloppy-023-ja
exchess-054-beta-ja      mskcp-145-ja      surprise-43-beta13-ja
gfc-08-rev5-ja           natwarlal-014-ja toledo-nanochess-2010-ja
gk-090-ja                olithink-530-ja   zzzzzz-351-ja
gullydeckel-215-pl10-ja phalanx-xxii-ja

Android Engines Tournament: Group C

2011-11-23T21:25:00.000-08:00

Group C has just finished a complete thirty seconds-per-move tournament in Chess for Android, played from both sides of all positions in the Nunn opening suite under the conditions described earlier.

Congratulations to Gary Linscott for GarboChess' promotion to Group B.

All games can be downloaded from the tournament page.

1 2 3 4 5
1 GarboChess3 * 10.5-9.5 9.5-10.5 15.0-5.0 16.0-4.0 51.0/80
2 Daydreamer 1.75 JA 9.5-10.5 * 12.0-8.0 14.5-5.5 13.0-7.0 49.0/80
3 GNU Chess 5.07.153.3b-32 10.5-9.5 8.0-12.0 * 11.0-9.0 16.0-4.0 45.5/80
4 Pepito v1.59 5.0-15.0 5.5-14.5 9.0-11.0 * 9.0-11.0 28.5/80
5 Rotor 0.6a 4.0-16.0 7.0-13.0 4.0-16.0 11.0-9.0 * 26.0/80

Android Engines Tournament: Group D

2011-11-15T17:58:00.000-08:00

After many more cycles on my Nexus One, Group D has just finished a complete thirty seconds-per-move tournament in Chess for Android, played from both sides of all positions in the Nunn opening suite under the conditions described earlier. Quite a shuffle-up in the results this time compared to the qualification tournament.

Congratulations to Aaron Becker for Daydreamer's promotion to Group C.

All games can be downloaded from the tournament page.

1 2 3 4 5
1 Daydreamer 1.75 JA * 12.0-8.0 11.0-9.0 14.5-5.5 16.0-4.0 53.5/80
2 sloppy 8.0-12.0 * 14.0-6.0 10.5-9.5 16.0-4.0 48.5/80
3 RedQueen 0.9.8 JA 9.0-11.0 6.0-14.0 * 11.5-8.5 14.0-6.0 40.5/80
4 gaviota v0.84 5.5-14.5 9.5-10.5 8.5-11.5 * 15.0-5.0 38.5/80
5 Diablo 0.5.1b JA 4.0-16.0 4.0-16.0 6.0-14.0 5.0-15.0 * 19.0/80

HELLO Micro-KIM

2011-11-12T23:04:00.000-08:00

The Micro-KIM arrived today! I did some initial experimentation with my 6502 cross-assembler and was happy that the paper tape format l recently added could be uploaded to the device without any problems. What better first program to write than "HELLO WORLD" (except only HELLO fits on the display)? It was fun figuring out how to control the display using low level 6502 programming.

Paper Tape Format Disassembler

2011-11-07T13:25:00.000-08:00

I have extended my cross-assembler with a built-in disassembler that can directly read from paper tape format (and a few other formats). For example, the following test assembly program

      .org $0200
      ldx #100
loop dex
      bne loop
      brk

is, under option -P, assembled into paper tape format (text representation):

;060200A264CAD0FD0003A5
;0000010001

Option -dP activates the disassembler on paper tape format represented as text, which disassembles the format above back to:

$0200 a2 64 ldx #$64
$0202 ca     dex
$0203 d0 fd bne $0202
$0205 00     brk

Android Engines Tournament: Group E

2011-11-06T12:40:00.000-08:00

After burning cycles on my Nexus One for many days, Group E has just finished a complete thirty seconds-per-move tournament, played from both sides of all positions in the Nunn opening suite under the conditions described earlier.

Congratulations to Ben-Hur Carlos Vieira Langoni Jr for RedQueen's promotion to Group D.

All games can be downloaded from the tournament page.

1 2 3 4 5

1 RedQueen 0.9.8 JA * 10.0-10.0 14.5-5.5 17.0-3.0 19.5-0.5 61.0/80

2 greko8.2 10.0-10.0 * 14.5-5.5 16.0-4.0 18.5-1.5 59.0/80

3 Sungorus 1.4 JA 5.5-14.5 5.5-14.5 * 13.0-7.0 16.0-4.0 40.0/80

4 Jazz v5.01 JA 3.0-17.0 4.0-16.0 7.0-13.0 * 14.5-5.5 28.5/80

5 DoubleCheck 1.3 0.5-19.5 1.5-18.5 4.0-16.0 5.5-14.5 * 11.5/80

Paper Tape Format

2011-11-04T09:32:00.000-07:00

As a present, my wife ordered the Micro-KIM from Briel Computers for me, which is a modern replica of the KIM-1 microcomputer. Even though I learned machine code on the 6510 of the Commodore 64, I remember seeing the KIM-1 in an electronics store much earlier, and I was intrigued right away. I can't wait for it to arrive to do some vintage programming.

In anticipation of the Micro-KIM's arrival, I extended my 65xx cross-assembler (available for Windows, Linux and MacOS) with the paper tape format, either in the original binary format (option -p) or in a text representation (option -P) so that its output can feed directly into the Kim's terminal interface. I simply generated the format based on old documentation and it is still untested. If someone is interested in trying it out, I would appreciate early feedback. Otherwise, I will report back when I get my Micro-KIM.

For example, using the assembler on this little test assembly program:

.org  $0100

.byte $FF $EE $DD $CC $BB $AA $00 $99 $88 $77 $66 $55

.byte $44 $33 $22 $11 $22 $33 $44 $55 $66 $77 $88 $99

yields the following text representation of the paper tape format:

;180100FFEEDDCCBBAA0099887766554433221122334455667788990AFD
;0000010001

Android Engines Tournament: Group F

2011-10-28T19:35:00.000-07:00

Group F has just finished a complete thirty seconds-per-move tournament, played from both sides of all positions in the Nunn opening suite under the conditions described earlier.

Congratulations to Evert Glebbeek for Jazz's promotion to Group E!

All games can be downloaded from the tournament page.

1    2 3 4 5
1 Jazz v5.01 JA * 15.5-4.5 18.0-2.0 18.5-1.5 19.5-0.5 71.5/80
2 ZCT-0.3.2500 4.5-15.5    * 13.5-6.5 17.0-3.0 16.0-4.0 51.0/80
3 BikJump v2.1 2.0-18.0 6.5-13.5    * 12.5-7.5 12.0-8.0 33.0/80
4 tscp181 1.5-18.5 3.0-17.0 7.5-12.5 * 12.5-7.5 24.5/80
5 umax48w 0.5-19.5 4.0-16.0 8.0-12.0 7.5-12.5 *    20.0/80

Soft6502 and H6X file format

2011-10-26T20:55:00.000-07:00

Charles Bond wrote a nifty 6502 simulator, called Soft6502, which I find useful for testing small programs written for the 65xx microprocessor family. The simulator supports the full 6502 instruction set and two 8-bit ports for input and output.

Programs can be entered one byte at the time through the keyboard or, more conveniently, loaded from file. The simulator uses the H6X file format, which is a simple, but surprisingly versatile way of representing 6502 code (essentially an ASCII representation of addresses followed by bytes).

I have extended my 65xx cross-assembler (available for Windows, Linux, and MacOS) to support this H6X file format, so that its output can be directly fed into Soft6502.