Gordon JC Pearce wrote:
  The keyboard problem on the other one is a bit odd -
not all the keys
 work (haven't worked out the pattern but it *seems* like the outer three
 on the ends of each row work, the middle ones being dead), and the key
 repeat starts instantly.  I'm a tad concerned that this is a sign of a
 dying keyboard controller chip 
Give it a good clean out with IPA first; generally I've seen some really
strange keyboard behaviour on micros when some of the switches start getting
tired and the contacts are dirty.
I did have my hands on a (bad) photocopy of the Superbrain schematics, but I'm
afraid I really couldn't lay my hands on them for you right now :(
One thing I found was that the cases on the machines really don't age well -
if you've got ones that are cosmetically nice, look after 'em!