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8kb to 16kb homebrew boards?


graywest

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Hello! I have a question about the AtariAge / PixelsPast homebrew boards that were sold several years ago. I have a couple of these bankswitch boards: http://www.pixelspast.com/homebrew/

 

I bought mine prepopulated, so there are a couple of resistors, a capacitor, and some sort of chip already soldered to the board. I also added my own socket.

 

I have used them successfully with 8k EPROMS. From what I understand from the link above, I should also be able to use the boards with 16k and 32k EPROMS. However, when I program my 16k homebrew to a 27C128 EPROM and try to play it on a real 2600, I only get a blank screen with a couple of vertical yellow stripes.

 

I'm posting a couple of pictures below for troubleshooting. Can anyone tell me what I'm doing wrong? Will my boards work with 16k ROMs? Do they need modification somehow? I tried with two different 16k EPROMS, so I don't think that's the problem - the programmer reports that they were both programmed correctly.

 

Thanks for the help!

post-6856-0-94005400-1427951972_thumb.jpg

post-6856-0-05429900-1427951994_thumb.jpg

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If 8K works OK, then I guess the logic chip is programmed with F8 bankswitching. I don't think that the logic chip can do F8, F6 and F4 bankswitching at the same time. So for 16K you need a logic chip for F6 and for 32K you need a chip with F4 bankswitching.

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If 8K works OK, then I guess the logic chip is programmed with F8 bankswitching. I don't think that the logic chip can do F8, F6 and F4 bankswitching at the same time. So for 16K you need a logic chip for F6 and for 32K you need a chip with F4 bankswitching.

 

That makes sense. Ok, so my next question is: does anyone sell 16kb homebrew boards? I don't see the boards that I purchased in the AtariAge store anymore.

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That makes sense. Ok, so my next question is: does anyone sell 16kb homebrew boards? I don't see the boards that I purchased in the AtariAge store anymore.

 

I'm guessing that Albert could still sell them to you.

I also have a PCB available that I described here: http://atariage.com/forums/topic/236413-where-to-get-pcbs-to-make-81632k-eprom-games-or-make-ones/

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  • 10 months later...

Looking at greywest's pictures I see his PCBs came with a ATF20V8B-15PC already installed.

My question is can I go up to 15ns on Tpd?

The specs on the Atari Age Bankswitch suggests ATF20V8B-10PC-ND(10ns).

I found a comparable replacement at 10ns Tpd (ATF 22V10C-10PU-ND) but it's a little more expensive.

Bottom line is can I still use the bankswitch code at 15ns?

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Looking at greywest's pictures I see his PCBs came with a ATF20V8B-15PC already installed.

My question is can I go up to 15ns on Tpd?

The specs on the Atari Age Bankswitch suggests ATF20V8B-10PC-ND(10ns).

I found a comparable replacement at 10ns Tpd (ATF 22V10C-10PU-ND) but it's a little more expensive.

Bottom line is can I still use the bankswitch code at 15ns?

 

yes

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