WTD: NEC V20 Hardware Manual, IBM PC schematics

From: Mark Tapley <mtapley_at_swri.edu>
Date: Wed Mar 12 09:02:00 2003

Hans wrote:

>Wasn't the V20 100% Bus (and thus hardware) compatible
>to the 8088 ?

I know it was highly compatible, if not completely. The DEC Rainbow could
take a V20 replacement for its 8088. The only other required change was to
the boot PROM, because the V20 completed a loop faster than the 8088 and
would cause trouble (not successfully boot) in the original PROM. The
putatative reason to make the switch was for an (approx., off the top of my
head) 5-10% speedup in execution.

I (think I) can supply details, including the change to the PROM, if anyone
is interested. I have not, however, tried the change myself.

                                                        - Mark
Received on Wed Mar 12 2003 - 09:02:00 GMT