Psion Chess as a UCI engine

[Damir]

He is not replying. I wrote to him several times, regarding the commercial desktop version of Chess Genius, asking if he could make it portable to Windows 10/11.
He never wrote back to me.

[Damir]

I have purchased the desktop 7.2 version for 35$, but it's not working on latest Windows.

[Michel]

v1.8 Pondering is now supported.

In addition I changed the download link to https://www.classicdosgames.com/game/Psion_Chess.html which is a no ads site. It also lists the program as freeware with permission of the copyright holders (Psion Software and Richard Lang). I have asked the site administrator for clarification.

GitHub integration now downloads the DOS binaries from https://www.classicdosgames.com/ and runs the full integration tests. So this means that the windows binary is tested on real windows.

https://github.com/vdbergh/psion-chess/ ... s/tag/v1.8

[towforce]

Does anyone here know Richard Lang personally?

Spoke to him at the 2000 WCC at the Alexandra Palace in London: he was there as a spectator - he didn't have an engine in the tournament. Not the least bit helpful in the context you're asking about, of course.

I have emailed him several times, asking if I could distribute the DOS program Psion Chess with https://github.com/vdbergh/psion-chess/ (or provide some other method to make it automatically available to the project) but he has not replied so far. ChessGenius for DOS is a free download (http://chessgenius.com/cg3dos/index.html) but this appears not to be the case for the older Psion Chess.

We were told earlier in this thread that Psion has made Psion Chess free software. I would take that to mean all versions. Also, Psion Chess appears to belong to Psion, not Richard - even if Genius belongs to Richard himself. If so, it's not in Richard's gift to grant you permissions relating to it.

Of course, talking to Richard is worthwhile for its own sake - even if it's not relevant to Psion Chess rights.

[Michel]

The bot now runs on a VPS. It can be challenged at

https://lichess.org/@/psion-chess

[Michel]

v1.13 UCI_Elo 1150 to 1650, calibrated on the CCRL blitz list.

Note: The rating of the emulated Psion Chess is about 1700 on the CCRL scale. Its lichess blitz rating (obtained from playing against other bots) is around 1850.

https://github.com/vdbergh/psion-chess/ ... /tag/v1.13

[Michel]

v1.14 fixes a serious bug when running at reduced speed (Cycles or UCI_Elo).

https://github.com/vdbergh/psion-chess/ ... /tag/v1.14

[Michel]

v1.18 The latest releases were all tweaks. Nonetheless upgrading is recommended.

https://github.com/vdbergh/psion-chess/ ... /tag/v1.18

[Michel]

v2.0 The most significant change is that ./psion -d will download and install the Psion Chess files automatically, after asking confirmation from the user. The adapter verifies the SHA-256 signatures and refuses to start if they don't match.

https://github.com/vdbergh/psion-chess/ ... s/tag/v2.0

The current Lichess ratings for the bot https://lichess.org/@/psion-chess (running on a slow VPS) are

Code: Select all

Bullet  1909
Blitz   1852
Rapid   1952

This Elo seems low compared to the anecdotal references to Psion Chess' rating on Google, given that the emulator is much faster than the hardware that Psion Chess used to run on. Lucas Braesch claims here https://github.com/lichess-org/lila/issues/19063 that the bot ratings on Lichess are 100s of Elo below their true rating (i.e. compared to human Elo). I don't know if that's true. Can anybody comment?

BTW: You can challenge the bot directly via this link: https://lichess.org/?user=psion-chess#friend (no account needed).

[Michel]

It seems that there is currently (Nov 1, 22:05 UTC) an issue with bots on Lichess. Cloudflare (unintentionally?) appears to block certain API calls.