1978 Sargon available as uci

[Harvey Williamson]

https://github.com/billforsternz/retro-sargon/releases

[Bryan Whitby]

Hi Harvey

Happy New Year.

I have been using Bill's Sargon UCI version for quite some time now and looking forward to his next upgrade with the goal of fixing the repetition problem whilst respecting the provenance of the program, i.e. without making any changes to the core Sargon 1978 assembly code. Also I think that he is going to change the game levels a little.

Regards
Bryan

[Fernando]

https://github.com/billforsternz/retro-sargon/releases[/quote

How is this thing used?
I see a lot of files, at least three that couold be the key to launch
Please, an explmation

[Harvey Williamson]

How is this thing used?
I see a lot of files, at least three that couold be the key to launch
Please, an explmation

Hi Fern,
You need the one that says uci-sargon this link should work https://github.com/billforsternz/retro- ... engine.exe then just install it the same as a uci engine.

[Fernando]

How is this thing used?
I see a lot of files, at least three that couold be the key to launch
Please, an explmation

Hi Fern,
You need the one that says uci-sargon this link should work https://github.com/billforsternz/retro- ... engine.exe then just install it the same as a uci engine.

Thanks!!
Fern

[Fernando]

BTW, is sargon 2 or 1?

Fern

[Harvey Williamson]

How is this thing used?
I see a lot of files, at least three that couold be the key to launch
Please, an explmation

Hi Fern,
You need the one that says uci-sargon this link should work https://github.com/billforsternz/retro- ... engine.exe then just install it the same as a uci engine.

1 i think.

[Fernando]

How is this thing used?
I see a lot of files, at least three that couold be the key to launch
Please, an explmation

Hi Fern,
You need the one that says uci-sargon this link should work https://github.com/billforsternz/retro- ... engine.exe then just install it the same as a uci engine.

1 i think.

In current PC play lot better than It used to do in old times ibn a 8088 or 286. . I played it in Arena and even If i got advantage very soon, it played his game lot more OK than what I was expecting. Once again a simple proposiktion is prooved: longer anaylsis trees makes an enormous difference.

Fern

[Harvey Williamson]

How is this thing used?
I see a lot of files, at least three that couold be the key to launch
Please, an explmation

Hi Fern,
You need the one that says uci-sargon this link should work https://github.com/billforsternz/retro- ... engine.exe then just install it the same as a uci engine.

1 i think.

In current PC play lot better than It used to do in old times ibn a 8088 or 286. . I played it in Arena and even If i got advantage very soon, it played his game lot more OK than what I was expecting. Once again a simple proposiktion is prooved: longer anaylsis trees makes an enormous difference.

Fern

It will be running a lot faster than it did in 78.

[paulhuk]

I think this the old Sargon 2.5 from the first auto response board days. Unless I am much mistaken. Playing this program is like stepping back in time to when programs would pawn pop as a matter of course and shuffle pieces too and fro’ in complex positions😀

[Bryan Whitby]

It is the original Sargon from 1978 which was written by Dan and Kathe Spracklen for the Z80-based Wavemate Jupiter III.
That is why there is so much interest in this Bill Foster project who has converted it into a UCI engine.

[mclane]

I would say this is the Sargon 1 that was published by Hayden software as BOOK !!!!

This is the book sources made into uci,

Sargon 1.
Assembler for 6502 cpu

[Bryan Whitby]

Yes McLane is correct, here is what Bill Foster wrote about it.

What is this?
The book "Sargon, a computer chess program", by Dan and Kathe Spracklen published by Hayden in 1978 presents the source code to the classic early chess program Sargon in Z80 assembly language. This is a project to bring the code presented in the book back to life in the modern era.

Why would you do that?
Why not? It was a fun challenge for a start. I love chess, I love chess software in general and retro chess software in particular. Not many people these days have familiarity and facility with Z80 assembly language, and it's nice to practise those skills and remember the good old days. The final result is fun to play with, it celebrates the pioneers and adds some twists and interest I didn't expect when I started (more on that later). Plus it's a pleasure to work on some software from a time when software could be important and significant without sprawling and metastasizing beyond the means of a single person to understand it in depth in a reasonable amount of time.

[BenRedic]

I would say this is the Sargon 1 that was published by Hayden software as BOOK !!!!

Probably, he actually mentioned this idea to me in an e-mail-exchange back in 2016, after I wrote to him about his C implementation of Microchess:

Finally, I will mention that I have purchased a second hand book that contains a source listing of Sargon. This is another future project of mine that you might be interested. I'd love to do something similar to my microchess project with Sargon. I'd provide the standard chess engine interface (i.e. Andre Adrian's idea) around it this time.

[bataais]

Over at TalkChess there's a lot talking about this one.
http://www.talkchess.com/forum3/viewtop ... =2&t=74027

Tibono wrote about Andre Adrian's little CP/M Jupiter Sargon Emulator:
http://www.talkchess.com/forum3/viewtop ... 10#p845624

http://www.andreadrian.de/schach/
http://www.andreadrian.de/schach/Jupiter-SARGON.zip

Bill Forster later answered:

Finally, I tried out the Jupiter emulation you linked to. I played quick a FixedDepth=4 game against Sargon with my Tarrasch GUI (below - Sargon almost demonstrates that my previous assertion that it could never beat me is wrong), then tried to reproduce with the Jupiter Emulator. Everything seems great for a while. As expected the emulator is about one order of magnitude slower than the native code (10 secs v 1 sec at level 4, approx). But sadly, the emulator (reliably/repeatedly) crashes after 14. g3, failing to produce 14... O-O-O. The provenance of the Jupiter code is the same as my code, I used Andre Adrian's transcription as one of my inputs. I might see if I can check my Git logs to see if there's a fix I made somewhere that could account for this.

http://www.talkchess.com/forum3/viewtop ... 20#p845725

Indeed there's a castling bug in the included SARGON.COM, I finally found it and fixed it.

Andre Adrian's code:

Code: Select all

CP10:	BIT	1,B 		; King side castle ?
	JRZ	.+11 		; No - jump
	PRTBLK	O.O,5 		; Output "O-O"
	JMPR	CP1C 		; Jump
	BIT	2,B 		; Queen side castle ?
	JRZ	.+11 		; No - jump
;X p74	
	PRTBLK	O.O.O,5		;  Output "O-O-O"
	JMPR	CP1C		; Jump
	PRTBLK	P.PEP,5		; Output "PxPep" - En passant

It's a relative jump bug. Bill Forster seems to have found the bug too, converting the relative value to absolute adresses:

Code: Select all

CP10:   BIT     1,b             ; King side castle ?
        JR      Z,rel020        ; No - jump
        PRTBLK  O_O,5           ; Output "O-O"
        JR      CP1C            ; Jump
rel020: BIT     2,b             ; Queen side castle ?
        JR      Z,rel021        ; No - jump
        PRTBLK  O_O_O,5         ; Output "O-O-O"
        JR      CP1C            ; Jump
rel021: PRTBLK  P_PEP,5         ; Output "PxPep" - En passant

To fix it, just use a hex-editor and change the 2 bytes of SARGON.COM, or get the attached version.

Code: Select all

Offset:	Was:	Should Be:
1CAF	09	0E
1CC1	09	0E

Sargon Jupiter Regards
Michael