[sdiy] MIDIVerb reverse engineering

[Pete Hartman]

Apologies :-D  I was reading while also working, and figured going to the
git at that point in the day was a BAD idea for my concentration :-)

On Wed, Jul 16, 2025 at 3:44 PM Eric Brombaugh <ebrombaugh at gmail.com> wrote:

> There are links to all four Youtube videos in the Github README - just
> scroll down. I've also posted the presentation slides which provide a
> high-level overview of how the DSP works - look in the 'doc' directory.
>
> Eric
>
> On 7/16/25 1:21 PM, Pete Hartman wrote:
> > I'm not sure the disposition of the videos, but I recall Paul describing
> > all this discrete logic and the pipeline in them.
> >
> > Pete
> >
> > On Wed, Jul 16, 2025 at 3:08 PM brianw <brianw at audiobanshee.com
> > <mailto:brianw at audiobanshee.com>> wrote:
> >
> >     Thank you!
> >
> >     I believe that it is very worthwhile to preserve knowledge of
> >     vintage electronics design.
> >
> >     I took a quick look at the collection of files, and specifically the
> >     schematic. It seems that the "DSP" is actually implemented via
> >     discrete logic chips. I also noticed that there is a pipeline which
> >     is potentially quite confusing. Do you have a high-level overview of
> >     how this "DSP" works?
> >
> >     I recall looking inside my A.R.T. MultiVerb back when it was new,
> >     and it also seemed to have discrete "DSP" controlled by a too-slow-
> >     for-digital-audio-sample-rates 8-bit MCU. I've long been curious how
> >     that worked.
> >
> >     Brian Willoughby
> >
> >
> >     On Jul 16, 2025, at 12:35 PM, Eric Brombaugh wrote:
> >      > Back in 2021 Paul Schreiber and I reverse engineered the MIDIVerb
> >     I and although Paul posted a number of Youtube videos to discuss
> >     what we'd learned, we decided at that time to keep the design
> >     materials we'd generated from that effort private. Now that Paul is
> >     no longer with us I've open-sourced the materials on Github:
> >      >
> >      > https://github.com/emeb/MIDIVerb_RE <https://github.com/emeb/
> >     MIDIVerb_RE>
> >      >
> >      > This repository includes schematics, presentation slides, source
> >     code for the disassembler, emulator and compiler, as well as SPICE
> >     and Verilog models of the logic. Anyone at all curious about how
> >     this product democratized the world of algorithmic reverb is invited
> >     to take a look - it's a fascinating glimpse into 1980's minimal TTL
> >     design and a testament to the genius of Alesis founder Keith Barr.
> >      >
> >      > Eric
> >
> >
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>
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