[Coco] Player 'pianos' (Was: DMP-106 Printer sighted)

Andrew keeper63 at cox.net
Wed Mar 15 10:38:21 EST 2006


Message: 7
Date: Tue, 14 Mar 2006 23:20:21 -0800
From: "Neil Morrison" <neilsmorr at hotpop.com>
Subject: Re: [Coco] Player 'pianos' (Was: DMP-106 Printer sighted)
To: "CoCoList for Color Computer Enthusiasts" <coco at maltedmedia.com>
Message-ID: <160401c64801$2b24ff90$dbe679d1 at NewBaby>
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After seeing a collection of players in the UK I had a delusion of building
a player roll cutter driven by computer which could be quickly programmed
for any player. It'd be a hoot to hear some modern pop tunes on one of
these!

Neil

---

Recently, via a local book sale, I stumbled across a collection of old 
Byte magazines from the late 1970's - lots of great covers. Anyhow, the 
September 1977 issue of Byte (music issue?) had a couple of articles on 
player pianos.

The first article was a description of how someone modified such a piano 
(a 1910 Steinway-DuoArt Baby Grand player - during a restoration of 
sorts, I believe) to allow them to control it with TTL logic. Schematic 
and mechanical diagrams are featured. The author doesn't mention what 
kind of computer it was hooked up to, only that the machine was "in the 
basement". The logic interface used was based on a serial to parallel 
bit-banger system, to keep the interface cabling from the computer to 
the piano down to a reasonable size (4-pair twisted).

The other article which followed it described the interesting anatomy of 
a different model player piano (some kind of 1920's DuoArt reproducer). 
In this piano, the author describes various interesting bits - the two 
which were most interesting from a computer standpoint was a feedback 
mechanism to keep the roll paper centered over the tracker bar, and a 
separate system, which utilized some (8) extra holes in the tracker bar, 
which provided a 4-bit per half (that is, 4 bits resolution for 44 keys, 
left and right) volume control of the piano. This was done via a 
pressure control system which converted the binary value into 16 levels 
of resolution via an ingenious mechanical bellows unit - essentially a 
mechanical digital to analog (D/A) convertor!

You know, these magazines were before my time with my Color Computer (I 
got my first one sometime in 1984 or so, when I was 10 or 11) - but 
everytime I read these old issues, up through about the early 1990's, I 
realize how much I miss the publication. I miss what it used to be, what 
it used to teach. Most of all, I worry that there is such a lack of 
similar magazines today - how will the next generation of hackers grow 
up, what they may miss in their education...

Ah well.

--- Andrew L. Ayers



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