real IMSAI 8080 playing songs from MUSIC SYSTEM BOARD By Software Technology (1977)

We made IMSAI write and draw on a graphics card, we made him talk , we made him play Wargames and games in cp/m, basic (including the milestones of Creative Computing), and so on.
Only one thing was missing: the sound.

This is the MUSIC SYSTEM BOARD of Software Technology.
It is an 'audio' card for S-100 bus systems built with only 5 components.
Probably the first sound card on the first microcomputers, precisely the Altair, the Sol-20, the Imsai. The synthesizer has (just over) 4 octaves and can play three voices simultaneously (Polyphonic). It does not provide any control over the width or envelope of the notes although it provides staggered notes, various articulation times, durations and tempos.
Each card provides output on a single channel, so two cards are required for stereo, or you work in mono.
Virtually as simple as it is intriguing, as well as extremely primal.

NB: This is the REAL board used on on August 25, 1978 in Philadelphia while the first Computer Music Festival (https://www.vintagecomputermusic.com) .
The card is used on sound demonstration on a SOL-20 (Processor Technology) to perform the Yankee song Doodle Dandy in mono channel and all performances are recorded on an LP I own (see photo) "The LP record made of the concert included 17 musical pieces performed on seven different computer synthesizers, representing programming by 11 people"

Here is David's article. H. Ahl in which he reviews the card:
https://www.atariarchives.org/bcc3/sh...
Ps: the song "Yankee Doodle Dandy" performed and recorded in '78 on the SOL-20 with this card you can listen to here:
https://www.vintagecomputermusic.com/....
Here the Philadelphia computer's set
https://www.swapmeetdave.com/PhilaMus...

ENJOY !
By Andrea Matteucci , Retrocampus