Paris, Feb 27th 1996

I read with very much interest in this digest various opinions about the
ambition of Player pianos to be (or not to be) early computers.
Perhaps you could be interested reading the english summary of an article I
wrote 2 years ago for the quarterly Journal ("La Revue") of the Musee
National des Techniques, in Paris. (The museum has a web site at:

    http://www.cnam.fr/museum/

where you may read all these summaries).

Memory gaps / Philippe Rouille (<rouille@cnam.fr>).- Musee des arts et
metiers, La Revue, feb. 1993, n 2, p.34-41. Translation from French into
English:  schindler@cnam.fr, 3 oct. 1994

Abstract

The "memory gaps" in question here are designed to restore pre-programmed
actions or pre-recorded data. There is a great deal of similarity between
the solutions adopted by very different branches of industry (textile,
publishing, manufacture of musical instruments, etc), for recording often
very complicated actions to be reproduced identically and repeatedly,
without direct human intervention. A long technical and, above all,
psychological journey was needed to arrive at these solutions which are in
turn being challenged today by other methods which they have helped to
create.

The cam, known and used since ancient times, and its derivatives, has long
been the best means of reproducing a pre-programmed movement. Used for
example in fullers earth mills or in the movements of "jacquemart"
clockwork mechanisms, these systems "in relief" present several limitations:

   - the duration of programmed operations depends directly on the
     circumference of the cylinder which supports the cams;

   - the cylinders can sometimes be changed, but the operation is difficult
     and storage is cumbersome;

   - all subsequent alteration of the programme is both difficult and costly.

The textile industry was to play a pioneer role in this respect. In 1725,
Basile Bouchon, a textile worker from Lyon, used a sheet of perforated
paper in a loom to ease the task of fellow workers whose job was to pull
the cords on the loom. The way the perforations were arranged was
established according to the pattern to be reproduced on the cloth. The
fact that Bouchon penetrated the needles he wanted neutralized into the
holes in the paper, while the active needles were pushed back by the raised
parts, is significant of the psychological difficulty in imagining that the
empty spaces could play an active role. However, the idea of commanding the
repeated actions of a machine, not by cams firmly attached to a rotating
shaft, but by holes made in a strip of paper, is a revolutionary one.

In 1728, Falcon, who worked with Basile Bouchon, replaced the paper strip
by a set of punch cards attached to one another, enabling the programme to
be changed rapidly. Vaucanson, in 1745, further automated the loom but used
a perforated cylinder, less flexible than the strips of paper or card.

These innovations were taken up and improved by Jacquard in the 19th
century with looms comprising up to two thousand hooks.

Other sectors were subsequently to make wide use of these "memory gaps". In
1843 in Lyon, Claude-Fe'lix Seytre patented a system using punch cards in
mechanical musical instruments.

Following confidential tests on various factors, perforated card or paper
became commonly used in pianos and automatic organs from around 1880 to
1890.

Several types of media coexisted with different types of reading methods.
The punch card, folded accordion-style, was notably used in street, barrel
and fairground organs; its thickness made it cumbersome, but its solidity
enabled intensive usage and the mechanical use of the sensors.

The roll of perforated paper provided the memory for pneumatically
activated instruments:  pianolas, violins, banjos, harps and so on.  Of
smaller volume, it enabled a large repertoire of very long pieces, but its
fragility restricted its use to pneumatic commands.

Disks - metal for music boxes composed of vibrating strips (symphonion,
polyphon), or cardboard for the family of organettes, small portable
harmoniums - were widespread from around 1890 to 1914.

Four reading systems were to appear successively and are still used,
according to needs:  mechanical reading, pneumatic reading, reading via
electrical contact and, last of all, the optical reading of punch cards and
tape in statistical or information processing machines. All these devices
were to enable increasingly faster reading speeds.

Around the end of the 19th century, several industrial sectors began to
grasp the potential of perforated media. Printing was one example, with the
invention in the US in 1885 of the "Monotype" which operates via coded
punched tape very similar to that used in pianolas.

Perforated media are also to be found in certain Braille writing machines
for the blind, as well as in telegraph or telex tapes, in arithmetical,
statistical and information processing machines and also, in industry, for
commanding large numbers of machine tools.

However, the use of perforated media to record and reproduce data also has
its limits. The system is deficient if it is required to instantly restore
very complex or nebulous data. It has therefore been replaced by similar
technologies:  magnetic media or laser scanning techniques.

MUSEE DES ARTS ET METIERS - 292, rue Saint-Martin - 75003 PARIS - FRANCE