HP 21MX E-series front panel keyboards

[Peter Brown]

Thanks Glen, Jay and Bob,

I think that I now understand what's going on.

The system that the keyboard comes from is an E series machine but all of 
the cards have been removed - it is quite possible that it at some time had 
additional booster microcode boards so that would expain the extra front 
panel cable.

What sort of microcode board would require direct access to the keyboard?

Bob - thanks for the kind offer of the 2113 chassis.  I currently have a 
couple of full size 2113's in almost working condition (thanks for your 
continuing help on that one) my hope was that I could get a smaller system 
working as well - hence the need for the short keyboard.

Glen - the document that you linked shows the problem quite well.  What I 
need is the PCA 5060-8343 what I have is PCA 5061-1343.  The metal work 
changes to convert a long front panel to a short one look to be fairly 
minimal and are probably within my capability (injury estimate: 2 bruised 
knuckles, a gash and some sort of deep graze)

I note from the circuit diagrams that the keyboards are basically the same 
with the larger PCA having some addtional bi-directional buffering to drive 
the additional keyboard outputs.  I thought that I might be able to saw down 
the keyboard PCA and discard the extra buffering bits but they seem fairly 
well integrated into the rest of the PCA.

Does anyone have a spare 5060-8343 that they might be convinced to part 
with? or failing that a whole front panel assembly for a 2105?

Thanks to all

Peter Brown