Looks like this board was discussed here:
Looks like its a digital to analogue converter.
found the following
" Computer Input: if MIDI Is used, then the computer Input is a MIDI interlace for the computer. (A commonly available piece of hardware that costs less than $200.00.) If audio such as live sound is used, an audio digitizer, (a digital microphone) is needed. An alternative to the simple digital microphone is a multiple channel audio digitizer such as the Dazzl A/D board, which will allow the performance events in the program to be generated from multiple channels of sound, as in alive sound board situation, with each instrument being assigned a different channel."
Ref in "next on campus spring 1991"
Dazzl Model 16/12 Analog to Digital
Converter An add-in board with 16
single-ended or 8 differential channels, a maximum sampling rate of 200
KHz, and a centronics-compatible
parallel port. Dazzl, Inc. (309) 674-