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Othello (A.K.A. Reversi)

Posted: Tue Oct 29, 2013 7:16 am
by stefano
This is another piece of history.
This game was written by Robert Halstead at the Real-Time Systems Lab at MIT.
In 1978 Leor Zolman really wanted to play this same game on his home computer, so he tried to rewrite it in assembly language.
He eventually ended up creating a full native C compiler for the 8080 CP/M systems with incredible features.
The z88dk under some aspect is less powerful than the BDS C, so I had to adapt the source and discovered how fascinating it was: digging here and there helped me to improve a bit our compiler's optimizer much enough to get a minimal WRX graphics version fitting in 16K. The graphics were missing in the original program, so I provided also a 'legacy' version as it would have been if someone decided to cross-compile othello.c at those times with BDS C on a CP/M system (which, in my opinion is not as hard as it seems).

The link provides the Othello game in many flavours: WRX HRG (16 and 32K), Text (sinclair style, legacy and Upper/Lowercase text on WRX) and ZX80 !!!

Re: Othello (A.K.A. Reversi)

Posted: Wed Oct 29, 2014 9:34 am
by stefano
Memotech HRG version, 16 and 32K RAM mode.
The 16K trick uses a customized scanline counter which has never been tested on the real hardware, feedback is welcome.

Re: Othello (A.K.A. Reversi)

Posted: Wed Oct 29, 2014 10:31 am
by sirmorris
Thanks for all the effort you're putting in to ensuring that the zx81 versions work! It's much appreciated :D

Re: Othello (A.K.A. Reversi)

Posted: Wed Oct 29, 2014 8:34 pm
by stefano
Well, doing it only for "theorical" systems wouldn't make much sense, right ?
I'd be glad if you (or someone else reading this post) could try on a real TV set my latest DSTAR related post (i.e. the "vanilla" text mode) to check whether the display is still stable:

download/file.php?id=2145

I put in a small hack to handle the display variations easily but now I'm not 100% sure of its compatibility.

Re: Othello (A.K.A. Reversi)

Posted: Sat Nov 08, 2014 10:57 am
by siggi
Hi Stefano
I played the 16K and 32K WRX versions and also DSTAR vanilla on my real ZX81 laptop: the display of all versions is stable :mrgreen:

Thanks a lot
Siggi

Re: Othello (A.K.A. Reversi)

Posted: Sat Nov 08, 2014 3:26 pm
by stefano
It's very good news, thanks a lot :)

Re: Othello (A.K.A. Reversi)

Posted: Tue Oct 10, 2017 1:31 pm
by stefano
OTHELLO_WRX32K.P
Othello in WRX mode, 32K RAM, bigger font variant
(14.41 KiB) Downloaded 15 times
..no much to say, this variant for the WRX graphics looks slightly better than the one I posted long ago.

Re: Othello (A.K.A. Reversi)

Posted: Wed Oct 11, 2017 1:44 pm
by stefano
The ARX mod variant is giving me some trouble.
I had random stability problems, but after playing it for a while I have the impression that it is stable enough. To save enough memory to fit in 16K I'm using the ROM font with some shift&overlap trick to simulate the missing characters.
OTHELLO_ARX16K.P
Othello, ARX 16K
(12.78 KiB) Downloaded 7 times

Re: Othello (A.K.A. Reversi)

Posted: Thu Oct 12, 2017 4:45 pm
by Andy Rea
stefano wrote:
Wed Oct 11, 2017 1:44 pm
The ARX mod variant is giving me some trouble.
I had random stability problems, but after playing it for a while I have the impression that it is stable enough. To save enough memory to fit in 16K I'm using the ROM font with some shift&overlap trick to simulate the missing characters.

OTHELLO_ARX16K.P
awe man... crashed half way through a game for me.... :(

great work on the game.

Regards Andy