AIM-65 displays - test-drb@ccmp.vtda.org

30 Apr 2002

...
 From: "Ethan Dicks"
&lt;erd_6502(a)yahoo.com&gt;

--- M H Stein &lt;mhstein(a)canada.com&gt; wrote:
  BTW, I've used 6821s & 6520s
interchangeably as well without problems.  
I only mentioned it because someone either here or on the CBM Hackers
list said they had problems substituting a 6821 for a 6520.  Since I
have tubes of 6821s and a small pad of 6520s, I was happy to verify
the substitution (I have, in the meantime, traded a tube of one for
a tube of the other across the pond, so I'm all set with both).

Hi
 It may be that he confused 6521's with 6821,6820 and 6520's.
The last three are essentially the same but the 6521 is different.
( or maybe I got it confused? I know one is different ).
Dwight