679 - Trevor Marshall's ETI3600, ETI4600 International Music Synthesisers and Maplin 3800 and Maplin 5600s Stereo Synthesisers

Many years ago the Australian magazine "Electronics Today International" published my designs for two partly digital, mostly analog, Electronic Music Synthesisers. the ETI 3600 and ETI 4600. Both were made available as kits of components Barry Wilkinson at ETI was responsible for the final packaging and kitting coordination. Maplin Electronics Ltd.(in the UK) subsequently picked up the designs, which they marketed as as the Maplin models 3800 and 5600s Electronic Music Synthesisers At the time I held two Australian provisional patents for the technologies I used in the Synthesiser designs. One related to the method for generating sawtooth waveforms, the other was for the method of using commutated resistors in voltage controlled filters. I never made any money out of the designs, or the patents, which have long ago been allowed to lapse. But it was fun! The original constructional articles for the ETI 3600/4600 can be found in these PDFs: October 1973, December 1973, January 1974, Feb 1974, March 1974, April 1974, July 1974, March 1975, April 1975, May 1975, August 1975 Although the earliest (4004) microprocessors were available at that time, it was not until the late-70's that I first started programming fully digital (Signetics 2650 based) Microcomputer systems. Consequently my early digital designs were hardware, and not firmware, based. Of course, these days, everything in my hardware and firmware is based on software designs - even the interconnections are controlled by the software in the EPLDs and PALs, instead of by wires. So many things have changed over the years.... Here is a mug shot of the Maplin 3800:

2010-10-02 12:32:31

http://www.trevormarshall.com/eti.htm


SileX