H89 CP/M hard-secored boot diskette

From: Eric Smith <eric-nospam-638_at_brouhaha.com>
Date: Thu Apr 3 19:30:00 2003

>> I have, of course, dumps of the 2 proms (one is 32*8, the other 256*4)
>> in my Z90. They're a lot less 'unobtainium' than many chips I deal
>> with!.
>
> That's good news, because I have a few CPU boards I'd like to upgrade...
> so, modern equivalent blanks are available? I haven't ripped labels off
> of any of them to see what they really are.

No, there are basically no modern equivalents for those parts.
Cypress makes some CMOS PROM and EPROM parts for bipolar replacement,
but not in those small sizes, and the ones that they do make are
extremely expensive. And it looks like they're phasing out the windowed
(erasable) parts.

If you need to replace those parts, you'll have to buy surplus or
NOS (new old stock) parts.
Received on Thu Apr 03 2003 - 19:30:00 BST