<I remember CUTS, but someone else mentioned 88-ACR and I'd never
Altair cassette interface which was narrow FSK at 300baud. The actual
board set was called 88-ACR and was a mits sio with a modified modem
board (tx/rx frequencies the same).
bell 103 uses differet tones for TX and recieve so for modem use it was
useless. It is however narrow FSK.
Allison