Are they TRS-DOS?
CP/M?  (RS? Pickles and Trout?(not the same fish as Jason's), or other?)
Xenix?  (actually, that would be model 16, but a II could be converted...)) 
TRSDOS.
"Programming today is a race between software engineers striving to build
bigger and better idiot-proof programs, and the Universe trying to produce
bigger and better idiots. So far, the Universe is winning." -- Rich Cook