Psion Chess as a UCI engine

[AdminX]

Thank You Michel!

[Tibono]

Hi Michel,

Windows version: beware it currently requires a qwerty (English-US) keyboard - I suspect it is because of the way it sends key input to the DosBox integrated layer.

Fails to run if keyb is FR (engine log: info string Cannot set up the position / bestmove 0000).

I could temporarily successfully run it after switching my Windows session input from FRA to ENG, hence the issue is definitely related to it.
I also tried to wrap it (with ChatGPT help) in a powershell script to switch back & forth to the qwerty KB, works in command mode, but no more if launched from my GUI (most probably, the GUI environment prevails).

Azerty regards,
Eric from France

[Michel]

Hi Eric,

Thanks a lot for reporting!!

The adapter plays by "pressing keys" on an emulated PC and Windows DOSBox by default loads the DOS keyboard layout matching the host keyboard. With AZERTY, Psion received other keys than the ones pressed.

Version 2.1 should fix this. Please have a look!

https://github.com/vdbergh/psion-chess/ ... s/tag/v2.1

Michel

[Tibono]

v2.1 definitely fixes!
Great, a big thank you Michel for sharing this nice Psion UCI version.
Warm regards,
Eric

[Michel]

The release packages are now fully self contained. We got permission to include the Psion files.

https://github.com/vdbergh/psion-chess/releases/latest

[Wilhelm]

Hi Michel.
many thanks for this classic engine
One dream of me would be an adapter for the old native chessbase engines like fritz 6, Hiarcs 8 or Junior 7 to use in any uci-gui. I hope that with todays KI and RCA it could be done.

William

[Michel]

There is now also a macOS binary (apple-silicon only) which seems to be quite a bit faster than the Linux binary. Note that the binary is unsigned (I don't want to pay Apple 99$ a year for a developers license). So it requires

Code: Select all

xattr -dr com.apple.quarantine psion-chess-macos-arm64

in the unpack directory to run it.

https://github.com/vdbergh/psion-chess/releases/latest

[Michel]

The adapter now shows node counts and nps in the info lines. On my laptop the nps is approximately 180 kN/s. In the CPW article on Psion Chess it is mentioned that the 68020 version achieved 4 kN/s at 28MHz (I could not verify the reference for this statement).

https://github.com/vdbergh/psion-chess/releases/latest

[Michel]

v2.7.1 Move overhead has been reduced from 30 ms to 10 ms (important for bullet games). The info lines now report the internal depth (always odd, between 3 and 15), seldepth (which may be higher), as well as the internal score (which has higher resolution: 4 cp instead of 10 cp).

https://github.com/vdbergh/psion-chess/releases/latest

[Michel]

v3.0.1 go depth, go nodes and go mate are now supported. This means that the UCI handling is now more or less complete.

https://github.com/vdbergh/psion-chess/releases/latest