[sdiy] Two interesting early SDIY projects

Mike Gorman mikegorman at btinternet.com
Mon Jan 3 14:57:05 CET 2011


I've got an Acorn Music 500 in my collection, as well as a Clef PDSG that is
similarly BBC Micro Based.

I've plans to build my own website in the not too distant future, to
document them both (along with many other things, including my magazine
collection and a few other projects I'm working on). I was planning to
reverse engineer the PDSG, as well as the control programs for the BBC (as
these programs are a bit buggy at the moment), so I might put a similar
project on my workstack for the Music 500.


Mike Gorman

-----Original Message-----
From: synth-diy-bounces at dropmix.xs4all.nl
[mailto:synth-diy-bounces at dropmix.xs4all.nl] On Behalf Of Mike Pepper
Sent: 03 January 2011 12:40
To: Synth-diy at synth-diy.org
Subject: Re: [sdiy] Two interesting early SDIY projects

> > > -----Original Message-----
> > > To: SDIY list
> > > Subject: [sdiy] Two interesting early SDIY projects
> > >
> > > While searching for someting completely different, I stumbled across a
> > > couple of interesting early '80s SDIY projects which I haven't seen
> > > before.
> > >
> > > 2-VCO monosynth with MIDI and patch storage from 1984/5:
> > >
> > >  http://koo.corpus.cam.ac.uk/projects/elric/
> > >
> > > 8-voice digital polysynth with MIDI and arpeggiator from 1983:
> > >
> > > http://koo.corpus.cam.ac.uk/projects/digipoly/index.html
> > >
> > > The Digipoly design was published in "Electronics and Wireless World"
> > > during
> > >
> > > 1985(?) - I would love to get a copy/scan of these articles if anybody
> > > them in their archive.
> > >

> > Mike Gorman
> > I've got the requisite Wireless World articles in front of me now.
> >
> > It will be a few days before I can get round to scanning them, so I'll
> > drop
> > you a note when they are done.
> >
> > There is very little code in the articles though, so you may have to
> > contact
> > the author for a copy. This apparently was either a 50 page listing of
> > 8088 source code or a BBC Micro 40 track disk!
> >
> Thanks a lot, Mike - that would be great. I've had some other expressions
> interest in the scans too.
> Even if we can't locate the 8088 code, it will still be interesting to see
> the TTL-based voice processor and how much, or haw little, it has in
> with units like the DK Synergy.

I had the articles at the time, though it was not only the problems of
getting the code and burning the EPROMS that finally put me of; if was the
sheer cost of the processor side. I had loads of TTL, and had already done a
hardware based organ/synth, but I seem to remember 8088's being over £100,
and in 1983, that was serious money for one chip!

Acorn sold an Add-On for the BBC called the Music 500/5000, which contained
a discrete component processor using TTL. Colin Fraser has a lot of info
here: http://www.colinfraser.com/m5000/m5000.htm , but as far as I am aware,
no one has ever had the circuit diagram, and the company, Hybrid,  are long
gone. It was designed by Chris Jordan, but to make things less easy, there
is a famous photographer of that name, which makes searching abit messy.
Would love to see a copy.


Synth-diy mailing list
Synth-diy at synth-diy.org

More information about the Synth-diy mailing list