Where I can find affordable 256x8 PROMs?

[norberto.collado koyado.com]

I did check eBay and other places and everything is very expensive. This is to create a copy the CDR86 PROM IC.

 

 

Here is the new CDR Floppy Controller.

 

[Lee Hart]

Wow; that was quick!

Looks like you made a few changes, like using the WD2797 instead of the WD1797. I assume it's more available?

I have a tube of MMI 6309-1 256x8 tri-state PROMs. Can you use them?

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[norberto.collado koyado.com]

WD2797 are more available and I do not need to deal with the analog calibration circuit of the WD1797, which is a pain to deal with. 

My Data I/O TOPS48 does not have the 6309 PROM listed, but I think I can you the AM27S29 to program the 6309 part. 

Thanks,

Norberto 

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Subject: Re: [sebhc] Where I can find affordable 256x8 PROMs?

 

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[norberto.collado koyado.com]

Programmer:

 

 

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[Joseph Travis]

I believe that I could program them on my Data I/O Model 29B.

Joe 

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[Frank Madison]

A GAL16V8 can be programmed as a ROM.

Sent: Friday, August 7, 2026 at 9:37 PM

From: "norberto.collado koyado.com" <norberto...@koyado.com>

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Subject: [sebhc] Where I can find affordable 256x8 PROMs?

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[norberto.collado koyado.com]

I have done it backwards. From PROM to GAL. I can try downloading the PROM contents onto a GAL and hopefully it will work.

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[Lee Hart]

I'll send you a couple and you can try them out.

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[norberto.collado koyado.com]

Thanks!

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