6502 CPU schematics

[Ethan Dicks]

On Sat, Mar 08, 2008 at 06:15:13PM +0000, Philip Belben wrote:
> Pete Turnbull:
> >So replacing the missing or damaged 6520 with a Motorola MC6821, which 
> >should be much easier to find, even has a degree of authenticity :-)
 
I have done this as well and not noticed any unusual behavior.  Because
there was a 6821 on every COMBOARD-I, I have a few in my parts box, but
not many 6520s.  It also works on the display board for an AIM-65, FWIW.

> Thanks for the tip.  6821 or 6820 goes on my mental wish list.

Try Unicorn Electronics - http://198.170.117.30/IC/6800.html - $3.49
each, but they do have a $20 minimum order.

-ethan

-- 
Ethan Dicks, A-333-S     Current South Pole Weather at  9-Mar-2008 at 09:30 Z
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Ethan.Dicks at usap.gov            http://penguincentral.com/penguincentral.html