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Curt Vendel

Posted up: POKEY chip schematics

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Many thanks Curt. Excited to see what else will appear on your site. I've just joined the museum facebook group so I can keep track of things.

 

So... what are you building with Joe?

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Nice :)

 

It reminds me of a project I did back in 1986 that used almost 100 misc IC's to essentially create a hard wired computer. Our schematics were also done on large sheets of paper, and hand drawn (no CAD system). It was quite impractical, but was essentially a sophisticated refrigeration control system that was under development, which was created a section at a time on a very large wire wrap breadboard. The idea was to migrate the final control aspects into a 6502 based board. Unfortunately it suffered the same fate as the Atari 1400 series, and never made it to a microprocessor design, or production for that matter.

 

Nice to see you posting again on the forums Curt.

 

- Michael

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I wonder if this can be used to improve emulation across the board, from MAME to Altirra?

 

I would have thought so, now they have true explanation of how the sound is derived and processed, should in time lead to near perfect sound if programmers want to take the fair bit of time to go through the schematics.

 

Not that I'm moaning at the sound we have, the above I would imagine is a big job, I'd be happy to just have the output we have.

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PMSL. It is nice that we now have something better than what was floating around, but I suspect the knowledge base won't be greatly expanded.

Pokey is probably the best known of the three, GTIA still might hold a secret or two (like 1/2 pixel shifted Gr. 9 ) and plenty was learned from the decaps of Antic but possibly a few tricks and exploits to be had.

What it lacking with Pokey though is the ability to easily compose music that takes advantage of all of it's capabilities. OK, I'm in agreement that existing trackers are left wanting but really it's nobody's fault and we're lucky to have what we do hae.

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I would have thought so, now they have true explanation of how the sound is derived and processed, should in time lead to near perfect sound if programmers want to take the fair bit of time to go through the schematics.

 

Not that I'm moaning at the sound we have, the above I would imagine is a big job, I'd be happy to just have the output we have.

I very briefly peeked at the schematics. I was expecting to see a lot more 74xx series chips in there besides a few logic gates and buffers and other implements. Tracing the wires out may be difficult. Hopefully this gets fully implemented now in the Hokey chips. And maybe a full Pokey replacement may become available for arcade and console applications that use more than just the audio logic.

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I wonder if this can be used to improve emulation across the board, from MAME to Altirra?

 

Unlikely. We already had reverse engineered schematics long ago. Even before I published schematics that I extracted from the die layout, we already had Pokeydocs, by Perry and Piotr. That was already full and very accurate schematics (I think with a single significant mistake).

 

This is invaluable historically, not technically. Unfortunately the images are a bit blurred. Way much better than the ones available before from the datasheet, but still some of the review comments are hard to read. And precisely that kind of comments might be the most interesting from the historical point of view.

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PMSL. It is nice that we now have something better than what was floating around, but I suspect the knowledge base won't be greatly expanded.

Pokey is probably the best known of the three, GTIA still might hold a secret or two (like 1/2 pixel shifted Gr. 9 ) and plenty was learned from the decaps of Antic but possibly a few tricks and exploits to be had.

What it lacking with Pokey though is the ability to easily compose music that takes advantage of all of it's capabilities. OK, I'm in agreement that existing trackers are left wanting but really it's nobody's fault and we're lucky to have what we do hae.

GTIA Schematics will be posted sometime next week...

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Just looked at the MOnSter 6502.....Wow, that is something else...Geeky as hell but is a good way...

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GTIA Schematics will be posted sometime next week...

 

Any original schematics are, of course, very welcome. But IMHO, CTIA would be more interesting than GTIA. We already have something for GTIA, but nothing for CTIA.

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Hello ijor

Unfortunately the images are a bit blurred. ..., but still some of the review comments are hard to read.

 

I haven't looked at the Zip and will not do so in the future (way to lazy to search for it), but if you can clip the parts you can not read and post them here... (But please don't cut off too much. Context often helps when deciphering what's been written)

 

Sincerely

 

Mathy

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Hello ijor

 

I haven't looked at the Zip and will not do so in the future (way to lazy to search for it), but if you can clip the parts you can not read and post them here... (But please don't cut off too much. Context often helps when deciphering what's been written)

 

Sincerely

 

Mathy

Is there some reason you cannot download and extract a zip file to view the high resolution images yourself?

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Hello ijor

 

I haven't looked at the Zip and will not do so in the future (way to lazy to search for it), but if you can clip the parts you can not read and post them here... (But please don't cut off too much. Context often helps when deciphering what's been written)

 

Sincerely

 

Mathy

http://www.atarimuseum.com/archives/chips/pokey.zip

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Hello guys

 

I was afraid the ZIP would contain a gazillion small files that would take days to sift through. Luckily it's only seven files. If anyone could point me to exactly what it is that's unreadable, that would help. I've had a quick look at the first two pictures and most of what's on those seems to be easy to read.

 

BTW how big is the schema? 864 x 559 mm/34 x 22 inches? To big for most xerox-machines, but a printing company might be able to scan them. Scanning usually results in a better quality picture than taking a picture.

 

Sincerely

 

Mathy

 

Edit: Just had a look at picture number 7. Ouch! That IS unreadable. Don't have much time today, will have a second look later.

Edited by Mathy
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BTW how big is the schema? 864 x 559 mm/34 x 22 inches? To big for most xerox-machines, but a printing company might be able to scan them. Scanning usually results in a better quality picture than taking a picture.

They're labeled as D size prints, so 34x22 inches is right. Some print shops have scanners that big, but I suspect most wouldn't touch these prints with the threatening legalese "reproduction forbidden" text.

 

The prints as-is are very much appreciated, but I think Curt may be able to get better pictures from his camera. Even the faint/blurry text parts have line thicknesses a few pixels across. The main problem is the contrast isn't above the noise floor of the camera, due to low light. The lighting is also at an angle, which enhances paper grain and imperfections. Better lighting and positioning would probably allow us to read everything, after a bit of enhancement.

 

As they are right now, switching the photos to greyscale, removing grain, and playing with contrast improves most of the text, but not the worst case bits.

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Each print can be photographed, or hand-scanned in sections. Then spliced together. No need for huge pro-level equipment. Do it carefully, do it right, and it'll look awesome.

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The main area that is really hard to read is the revision notes, at the top right on every sheet. But now I'm not sure it is that important. I was hoping it would detail the difference between Pokey rev A and rev B, but seems this is not included.

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