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Unusual discovery of Barry's Orlando 32k colors extension by ATREUS of Atari Area Forum

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tOriman
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Unusual discovery of Barry's Orlando 32k colors extension by ATREUS of Atari Area Forum

Post by tOriman »

Hi,

I suspect that many Atarians, especially older ones, have heard or read about the expansion of the AtariST computer's color display capability to 32k colors developed and described by Barry Orlando in the 32kcolors.zip file available on the Internet. Unfortunately - the file did not contain the schematic, but Barry wrote that for anyone who sends him a letter with feedback - he will send a copy of the schematic. Personally, I never lived to see a reply and I tried to contact him from 25 years ago.... Literally three days ago, our buddy Atarian - nicknamed ATREUS - from the Polish Atari Area, while browsing through old issues of Atari Interface magazine on the Atarimania site, made a remarkable discovery. Literally like Indiana Jones :). It turned out that in the October 1989 issue is published the text of the 32kcolor file, along with a complete diagram of this extension and a listing of a test program of its use. I am personally still in shock - how was it possible that for decades no one came across this document.... Eternal respect to Atreus for his curiosity and willingness to learn about the history related to various aspects of Atari computers.

Hat off.

Link to archive on Atarimania - https://www.atarimania.com/atari-magazi ... e_108.html - October 1989 page 24.

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tOri
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Re: Unusual discovery of Barry's Orlando 32k colors extension by ATREUS of Atari Area Forum

Post by exxos »

@tOriman That is amazing! A very long mystery possibly solved :D :thumbup:


I extracted the pages here :)

atari-interface-magazine-1989-10_page-0026.jpg
atari-interface-magazine-1989-10_page-0026.jpg (351.38 KiB) Viewed 2001 times
atari-interface-magazine-1989-10_page-0027.jpg
atari-interface-magazine-1989-10_page-0027.jpg (308.39 KiB) Viewed 2001 times
atari-interface-magazine-1989-10_page-0028.jpg
atari-interface-magazine-1989-10_page-0028.jpg (284.58 KiB) Viewed 2001 times
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Re: Unusual discovery of Barry's Orlando 32k colors extension by ATREUS of Atari Area Forum

Post by Steve »

@tOriman Very cool, is this something you personally might design a PCB for?
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Re: Unusual discovery of Barry's Orlando 32k colors extension by ATREUS of Atari Area Forum

Post by tOriman »

Hi,

Not now because I can't. I think that Sporniket will do something more...I wrote only info here.

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Re: Unusual discovery of Barry's Orlando 32k colors extension by ATREUS of Atari Area Forum

Post by DoG »

Very cool find. What chip is U27 and U23 that it is refering to in the schematics?
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Re: Unusual discovery of Barry's Orlando 32k colors extension by ATREUS of Atari Area Forum

Post by Steve »

Isn't this the same thing? viewtopic.php?t=302
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Re: Unusual discovery of Barry's Orlando 32k colors extension by ATREUS of Atari Area Forum

Post by tOriman »

Hi,

I attach an explanation - it is most likely these chips from 520ST schematics (near SHIFTER)

tOri
SCH.jpg
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Re: Unusual discovery of Barry's Orlando 32k colors extension by ATREUS of Atari Area Forum

Post by tOriman »

Steve wrote: Tue Jul 15, 2025 6:54 pm Isn't this the same thing? viewtopic.php?t=302
It is a nice try to recreate this project by @sporniket not exactly the same project.

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Re: Unusual discovery of Barry's Orlando 32k colors extension by ATREUS of Atari Area Forum

Post by mrbombermillzy »

@Steve Spornikets version is a (great) guess at the original design and enhances the palette by adding an extra bit so 16bpp/64k colours.
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Re: Unusual discovery of Barry's Orlando 32k colors extension by ATREUS of Atari Area Forum

Post by sporniket »

Great find :)

I will study that during the summer, to see if I need to amend something on my design. No promise though, because not enough time (and I never had a working ST to test it anyway).
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