--- Robert Krten <root(a)parse.com> wrote:
  For those of you who missed the announcement in
alt.sys.pdp8,
 I've now almost completed the M220 version B schematic.  It's
 available at:
 
http://www.parse.com/~pdp8/pdp8i/m220b.html 
Cool!  Thanks!  I have a few M220 cards that will eventually benefit
 from your efforts (I borrowed them from a parts machine
to keep the 
main machines running).
  The trials and tribulations of the PDP-8/I restoration
can be
 found at:
 
http://www.parse.com/~pdp8/pdp8i/restore.html
 Plenty-o-dead 7474's in that one :-) 
That's been my experience, too.  I have replaced as many as 8 7474s
at a go to get an -8/L back on its feet.  I don't recall replacing
any other chip, as a matter of fact.
-ethan