Aart's Blog

Chess of Android supports setting up Nalimov, Gaviota, and Scorpio endgame tablebases on the SD card, but Robbobases were missing. Therefore, I added support for RobboTotalBases as well. I tested the setup with the UCI engine IvanHoe 999947c (modified slightly to relax file permissions when reading) and the /3 and /4 piece directories on the SD card. The engine reports info string 66 RobboTotalBases registered with 2499 indici 0mb and plays simple endgames flawlessly afterwards. The setup will be in the next release of Chess for Android.

I compiled Vladimir Medvedev's UCI engine GreKo for Android (ARM) for use in  Chess for Android  and put the binary on UCI engines for Android (with kind permission of Vladimir). Below a screenshot and the results of a few quick matches with other engines on a Nexus S (1GHz Hummingbird) with 32MB hash and Nalimov/Gaviota/Scorpio endgame tablebases on SD card. Greko 8.0 - RobboLito 0.085e4l     0.0 - 10.0  +0/-10/=0   0.00% Greko 8.0 - IvanHoe-Beta v999947c  0.5 - 9.5   +0/-9/=1    5.00% Greko 8.0 - Stockfish 2.0          1.0 - 9.0   +1/-9/=0   10.00% Greko 8.0 - Rotor 0.6a             3.0 - 7.0   +2/-6/=2   30.00% Greko 8.0 - Gaviota v0.80.0.107    5.5 - 4.5   +4/-3/=3   55.00% Greko 8.0 - GNU Chess 5.07.153.3b  6.0 - 4.0   +6/-4/=0   60.00% Greko 8.0 - RedQueen 0.9.5         6.5 - 3.5   +5/-2/=3 ...

Multi-core Android devices are becoming more widespread. Therefore, v2.8.2. of Chess for Android, available from the Android Market or as direct download , adds support for setting up UCI engines with parallel search. Unfortunately, the UCI protocol did not standardize the option name for parallel search (despite some efforts ) so the GUI simply looks in the UCI engine output for commonly used option names like "Cores", "Processors", "Threads", and "CPUs". The GUI then presents this choice in the option setup window (always labeled as CPUs), and eventually sends any selected value back to the engine using the recognized option name. Please let me know if you would like to see alternative option names for other UCI engines on Android with parallel search. As for all other options, only option values supported by the engine can be selected in the setup window. Below a screenshot of the new UCI option setup window.

It is nice to hear that others sometimes find my toy projects useful. As I reported in an earlier blog entry , a while back I implemented a 6510 cross-assembler to relive the good old times of programming a Commodore 64. Today I got an email from Antonino Brisindi who is using this assembler to burn an EPROM for his home-made 6502-based microcomputer. Below you see a picture of his impressive project in progress.

Marc F. Ferguson is writing about experiences with rooting the Nook Color on his blog FergyTech and he kindly emailed me the following pictures of Chess for Android running on the Nook Color. It is cool to see so many new devices running Android. Thanks Marc!

I compiled Ben-Hur Carlos Langoni's UCI engine RedQueen for Android (ARM), and put the binary on UCI engines for Android . Below screenshots and results of a few quick matches against other engines on a Nexus One (1GHz Snapdragon) with 32MB hash and Nalimov/Gaviota/Scorpio endgame tablebases on SD card. RedQueen 0.9.5 - Stockfish 2.0          0.0 - 10.0 +0/-10/=0    0.00% RedQueen 0.9.5 - Toga II 1.4.1SE        0.0 - 10.0 +0/-10/=0    0.00% RedQueen 0.9.5 - IvanHoe-Beta v999947c  0.0 - 10.0 +0/-10/=0    0.00% RedQueen 0.9.5 - Rotor 0.6a             3.0 - 7.0  +3/-7/=0    30.00% RedQueen 0.9.5 - GNU Chess 5.07.170.7b  3.0 - 7.0  +1/-5/=4    30.00% RedQueen 0.9.5 - gaviota v0.80.0.107    3.5 - 6.5  +3/-6/=1    35.00% RedQueen 0.9.5 - BikJump v2.1P          8.0 - 2.0  +8/-2/=0 ...

I just released version 2.8 of Chess for Android, available from the Android Market or as direct download . New features include: full PGN support (clipboard import/export, file load/save) improved layout for xlarge screen sizes (api 9 and up) bug fix in draw detection after FEN import To load a game from a file in PGN format, long press the notation window, select "Load Game from SD", and navigate to the file. This opens another window with the actual games in that file. Then select the desired game. Very large PGN files may take a while to download (or even run out of memory), but the idea is that future versions will be able to navigate quickly between successive games. I have tried to make the PGN parser reasonably robust (it accepts sloppy SAN for instance), but certain non-standard constructs are rejected. Please let me know if you encounter bugs though.

User PJ+ at the OpenChess forum implemented a nifty client utility that converts Chess for Android to a client for a remote chess server. To make this work (assuming you already have a remote chess server running at some hostname and port), simply do the following steps. Download the version of Chess for Android that grants network permission to its UCI clients (the default version at the market does not do this for obvious security reasons). Download PJ+'s client-android-cli utility. Construct a file, for example uci_client , that contains the single line ./client-android-cli <hostname > < port > for the hostname and port of the remote chess server. Copy 2. and 3. to SD card, then install these from SD just like the first-time install of UCI engines. Finally, the single line file uci_client can now be imported as any other UCI engine, and will connect to the remote chess server. I tried this method myself connecting Chess for Android as client to a remote c...

Jan Brouwer ported his UCI engine Rotor  to Android. Below the results of a few matches against other engines on a Nexus One (1GHz Snapdragon), one second-per-move, 16MB hash, and Nalimov/Gaviota/Scorpio endgame tablebases on SD card. Rotor 0.6a - Stockfish 2.0           0.0 - 10.0    +0/-10/=0      0.00% Rotor 0.6a - Toga II 1.4.1SE         0.5 -  9.5    +0/-9/=1       5.00% Rotor 0.6a - gaviota v0.80.0.107     5.5 -  4.5    +5/-4/=1      55.00% Rotor 0.6a - GNU Chess 5.07.170.7b   7.0 -  3.0    +7/-3/=0      70.00% Rotor 0.6a - BikJump v2.1P          10.0 -  0.0    +10/-0/=0    100.00% Rotor 0.6a - ZCT-0.3.2500           10.0 -  0.0    +10/-0/=0    100.00%

I don't have a tablet myself yet, but Roel from Belgium kindly emailed me this picture of Chess for Android running on a 7 inch tablet. As you can see, he was running an engine-engine match between UCI engines at the time. Thanks Roel!