Marquette "MUSE"--DEC mini/file server circa 1986-88

From: Bob Stek <bobstek_at_ix.netcom.com>
Date: Mon Apr 17 12:43:57 2000

I have one of the original Triadex Muses's - obviously quite different from
the DEC unit. A description of it from Hal Chamberlin's book The Musical
Applications of Microprocessors

THE MUSE
(as described in Hal Chamberlin's Book)

Thirty-eight different digital signals are generated by several counter
stages and a 31-stage shift register. These signals, along with constants 0
and 1, are connected to 40 signal rows. Eight 40-position slide switches,
divided into two groups of four, act as columns and can connect to any
individual row signal. Four of these switches, which are called THEME
controls feed a parity generator, whose output feeds the 31-position shift
register. The other four switches, designated INTERVAL controls, are
connected through some translation logic to a 5-bit DAC, which drives a VCO
tone generator. The VCO and DAC are adjusted so that the step size is a
semitone on the equi-tempered scale. The translation logic converts its
4-bit input into 5-bit output according to the conventions of the major
musical scale. An adjustable low-frequency oscillator clocks the counters
and shift register.
The rows driven by the counters and constants 0 and 1 are designated as the
"C" (counter) region. Five of these rows are connected to a simple 5-bit
counter, while two more connect to a divide-by-6 and a divide-by-12 counter.
The outputs of the various counts are normally used for short, highly
ordered, sequences. For example: if the "A" switch is set to row "C1", B to
C2, C to C4 etc., the device will generate an ascending major scale.
Essentially, a binary counter has been connected to the DAC, which would be
expected to generate an ascending staircase waveform.
If switch A is moved to the C? position, the scale will still ascend, but by
alternate intervals of one note and three notes. Moving D and B back to the
OFF position (contant 0 row), results in a pair of trills:
C-D-C-D-G-A-G-A-C-D... Many other combinations, opf course, are possible,
but the sequence length will never be more than 64 notes using the C6 row,
or 32 notes otherwise.
The 31 rows in the "B" (binary) region are driven by the 31-stage shift
register, which shifts downwards from row 1 to 2 to 3 etc. The four THEME
switches are used to control the shift register by determining what will be
shifted into the register's first stage input. If they are set in the C
region, then the register acts merely as a delay line. This can be useful in
creating canon effects. However, if one or more are set in the B region,
then a feedback path into the shift register is created and complex
sequences can result. One possibility is to set the THEME switches for a
complex sequence, set three of the INTERVAL switches in the C region for a
repetitive tone pattern, and set the fourth somewhere in the B region. The
result is that the repetitive pattern is modified according to the shift
register pattern. The number of unique combinations is, for all practical
purposes, infinite.

There are two software simulations available - sorry, don't have the URL's
anymore - ANKLUND and Muse11. Muse 11 is quite good - I haven't tried
ANKLUND. It's a fun thing to play around with - came out in the early 70's
I think, so it's quite on-topic. Noteworthy (pun intended) is that one of
the creators of the original Muse was
that-famous-AI-guy-at-MIT (damn, I gotta get my memory refresh rate
increased again!)

Bob Stek
Saver of Lost SOLs


-----Original Message-----
From: owner-classiccmp_at_classiccmp.org
[mailto:owner-classiccmp_at_classiccmp.org]On Behalf Of John Allain
Sent: Monday, April 17, 2000 1:03 PM
To: classiccmp_at_classiccmp.org
Subject: RE: Marquette "MUSE"--DEC mini/file server circa 1986-88



A friend of mine told me a while back that he had seen
a thing called a 'Micro (or mini) Muse' a few years ago
at a trade show. He said it was doing music synthesis
and that it attracted quite a crowd.

Could this be related? Sounds like the "macro" MUSE
was doing AD/DA, such a thing could be used to make a
synthesizer demo... Anybody?

John A.
Received on Mon Apr 17 2000 - 12:43:57 BST

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