[sdiy] Identification of an unknown MIDI CV interface

[brianw]

I don't think they called it open source, but I certainly built a few designs that were freely shared. You'd probably have to download from a BBS!

For that matter, the Apple ][ came with a schematic and commented 6502 assembly source for the ROM (other than Basic).

There was a speech synthesizer card that I built by hand, entirely based on the schematic from the manual. But I don't think that was necessarily intended to be an "open" design.

Brian

p.s. Florian, does this Prodigy MIDI-to-CV interface have the concept of Local Off? I'm trying to imagine what to expect when playing the built-in keyboard at the same time as incoming MIDI is being interpreted.


On Sep 26, 2022, at 3:50 PM, grant musictechnologiesgroup.com <grant at musictechnologiesgroup.com> wrote:
> Was there any such thing as open source in the 80's?
> 
> That's probably a Ferranti DAC chip. I think I have a few if anyone 
> wants to get reacquainted.
> 
> Definitely looking forward to the EPROM dump, but this would be pretty 
> easy to recreate in a jiffy.
> 
> GB
> 
> ------ Original Message ------
> From: "brianw" <brianw at audiobanshee.com>
> To: "synth-diy at synth-diy.org" <synth-diy at synth-diy.org>
> Sent: 9/26/2022 3:29:26 PM
> Subject: Re: [sdiy] Identification of an unknown MIDI CV interface
> 
>> My first impression is that the perf-board says this was a one-off (not to mention the flying wires).
>> 
>> However, the sticker on the EPROM hints that it might have been from an open source project, although it could just be that the homebrew designer had a label printer and it was 100% DIY.
>> 
>> Disassembling the EPROM could prove quite useful, assuming that P80C32 has a known instruction set. What is this Ferranti that you mention, Mike? Google says power grid, defense.
>> 
>> Brian
>> 
>> On Sep 26, 2022, at 1:36 PM, Mike Bryant <mbryant at futurehorizons.com> wrote:
>>> I haven’t seen a Ferranti chip since the early 80s
>>> 
>>> From: Synth-diy [mailto:synth-diy-bounces at synth-diy.org] On Behalf Of Florian Anwander
>>> Sent: 26 September 2022 21:21
>>> To: synth-diy at synth-diy.org
>>> Subject: [sdiy] Identification of an unknown MIDI CV interface
>>> 
>>> Hello
>>> 
>>> Does anyone of you know this MIDI-CV interface? It is built into a Prodigy. You can see a logo "B E" and a board name "HPG110". Must be quite old, because I doubt someone has developed anything seriously on an Intel P80C32 from 1996 within the recent 20 years...
>>> 
>>> https://florian-anwander.de/moog_prodigy/Unknown_Midi_Interface.jpg
>>> 
>>> Regards
>>> Florian