Solid State Music S-100 Notes Web page

Please check my S-100 Solid State Music document list page. To return to my S-100 Web page follow this link. Last update Feb 29 2024. This document copyright Herbert R. Johnson 2024, documents from others have their copyrights.
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On another Web page are notes from Iain McFetridge who designed the SSM VB3.Check this Web page for a VB3 VB3A comparison. This Web page has notes about the Philadelphia Music Festival which included an SSM music card; and SSM as an producer of electronic music chips and boards. - Herb

Electronic music and SSM

Philadelphia and electronic music on S-100

Found this Web site on vintage computer music which includes notes about a recording made at the Philadelphia Computer Music Festival and released in 1979. The page linked describes the use of Solid State Music S-100 hardware to make some of the album tracks. The Festival was recorded during the Personal Computing '78 show in Philadelphia I contacted the Web site and, in 2008, the site owner said he did not have more information about the software or hardware used.

SSM and ALF synthesizers

SSM produced a SB1 music synthesizer board, and provided a program MUS-X1 to operate the board. The following is thanks to a Jan 2017 discussion from 'stynx', about the SB1, and about ALF Products who produced the boards noted. He was in contact with two of the ALF founders. For more information on ALF check wikipedia- Herb

ALF produced 2 types of S-100 sound-boards. One was 4 channel rectangle waveform without volume control and the other was a fully blown synth voice (hybrid-synth) with AHDS and filters, one voice per card. 8 cards of the later could be used in a single S-100 computer. The complex card was expensive and you would have to pay beyond $12000 in 1977 for a 8 voice synth in a preconfigured computer offered by ALF. ALF introduced the quad-channel simple rectangle synth to the Apple II in 1978 as the MC-16 with 3 Voices (up to 3 cards supported in a single system) and 8bit volume-control and 16bit accuracy.

The MC16 was hailed as near pitch-perfect but needed an expensive 1.782mhz quartz and 3 companding DACs. 3 Cards would easily cost $300-$400 for a 9-voice system. TI took the design as input for their SN76489 programmable sound generator (PSG) which ALF in turn used in 1980 on the MC-1 sound-card for the Apple II to get 9 voices (3 TI chips) for less than $100 (12bit accuracy and 4 bit volume). This was good enough for most.

The AY3-891X from GI was a clone of the TI-chip. The AY3-891X was licensed by Yamaha as the YM2149 and paved the road for the integrated FM synthesizer-chips from Yamaha. The Apple II was beginning to decline at this point. And the focus was more on the fresh 16bit/32bit systems.

In 1979 Mountain Computer created the Mountain Computer Music System for the Apple II that was greatly influenced by the the ALF S-100 synth board as well as the SSM SB1. The MCMS had a 2K "wavetable" with 256 bytes per waveform/channel and a somewhat controllable lowpass-filter. It had 8 voices (stereo) and used 2 Apple II card slots. The synthesis was mainly digital with very little post processing via analog filtering. You could say that the MCMS is one of the earliest fully functional all-in-one synthesizer systems for a personal/home computer. The MCMS design was later (1983/84) licensed by Passport to create a single board combined (extremely rare) synthesizer/midi-card for the Apple II.

Both the SSM SB1 and the ALF S-100 cards share a lot of similarities as they both are sample based hybrid synthesizers. They were a defining part of the computer-music revolution. These boards allowed even children who didn’t know musical notes to compose music. The C64 used a hybrid synth like the ALF or SSM S-100 cards on a single chip (SID). The Sid had fixed digital waveforms though.

ALF went on to get big in the disk-duplicator market, which they developed to supply the growing need to have music to play on the ALF cards, with the ALF MC1 being the last music related product from ALF.


Herb Johnson
New Jersey, USA

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