Re: 8088 card replica

From: Michał Pleban <lists_at_michau.name>
Date: Mon, 26 Mar 2018 11:17:22 +0200
Message-ID: <5AB8BAA2.5030803@michau.name>
Hello!

Mia Magnusson wrote:

> Btw the original schematics (CBM_8088_CPU_co-processor_schematic.pdf)
> is hard to read. Just to make sure, is it indeed an 6525? All pin
> numbers / signals match a 6525 while the schematics says "6523" which
> seems like a bad copy.

There is a 6525A in my board. But the board uses the chip only for I/O
pins, so I presume you can use either 6523 or 6525.

> If you are anyway going to change the construction, maybe you should
> consider some dual port ram? Although probably both more expensive and
> harder to get, it would be far nicer and probably faster too.

I was thinking about dual-port RAM to simulate video RAM, so that the
8088 could write to it simultaneously with 6509 reading from it and
copying to CBM-II video RAM. But this kind of setup might be complicated.

Regards,
Michau.
Received on 2018-03-26 12:07:39

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