Stored indoors for some years and then powering up, missing notes and
some top panel sw functions missing.
full sm here
http://www.synfo.nl/servicemanuals/R...VICE_NOTES.pdf
same 2 notes ,not each octave , but as keyboard is scanned as 8x8 matrix
keys 8n and 8n-2 are missing , n= 1 to 8.
Hopefully that means the 74LS138 3 to 8 demultiplexer did not survive
1/3 century,internal metalisation creep or something, rather than main
micro problem.