[TUHS] Unix v6 chess source code?

[Jonathan Gray]

On Tue, Jan 31, 2023 at 08:11:29AM +0100, Mattis Lind wrote:
> Hello!
> 
> I saw someone playing chess on their pdp-11 and thought it could be an
> interesting project to run on my pdp-11. At this point the RK05s are not
> yet running so booting unix v6 is not possible.
> 
> I then thought that if the source code could be found it might be possible
> to get it to run standalone with some modifications.
> 
> After some googling I found the archive
> https://www.tuhs.org/Archive/Distributions/UNSW/7/record0.tar.gz
> 
> which contained a chess.lib file. It appeared that this archive contained
> source code for some kind of chess program. I have been told that it isn't
> the chess written by Ken Thompson so the question is who wrote it? There
> are not many comments in the code. Could be interesting to know more about
> this chess implementation.
> 
> Just looking through the source files and the mk file show that it is
> missing a set of files. The mk file references a set of "b"-prefixed
> assembly files, bgen.s, bmove.s, bheur.s and bplay.s which are present in
> the archive. But it also references a set of files with "w"-prefix, wgen.s,
> wmove.s, wheur.s and wplay.s which are missing.
> 
> I also recognise that there is an include file, "old.h" that is included
> from all c-modules that most likely is present in the overload.lib which
> seems to be an overlay loader.
> 
> 
> Anyone that has an idea how this thing was built once upon a time?
> 
> /Mattis

a pre-v7 version of those files exists in

tuhs/Applications/Spencer_Tapes/unsw3.tar.gz
usr/source/chess

tuhs/Applications/Usenix_77/ug091377.tar.gz
3/ken/chess

code is the same in the above

v7 chess only has a few small changes, such as seek->lseek

UNSW 107, UNIX L6 Source 2
tuhs/Distributions/UNSW/107/107.tar.gz also has
gt40/chess/ch.mac.z

;
; chess display for gt40
;
; note: not a chess program, just the display
;
;       probably for use with unix chess.
;