Abstract-
David Link
Memory
for Love Letters
Computer Archaeology of a Very Early Program
From
August 1953 to May 1954 strange love-letters appeared on the notice board
of Manchester University’s Computer Department:
DARLING SWEETHEART
YOU ARE MY AVID FELLOW FEELING. MY AFFECTION CURIOUSLY CLINGS TO YOUR
PASSIONATE WISH. MY LIKING YEARNS FOR YOUR HEART. YOU ARE MY WISTFUL SYMPATHY:
MY TENDER LIKING.
YOURS BEAUTIFULLY
M. U. C.
The acronym “M.U.C.” stood for “Manchester University
Computer”, the earliest fully electronic, programmable, and universal
calculating machine; the fully functional prototype was completed in June
1948. One of the very first software developers, Christopher Strachey
(1916–1975), had used the built-in random generator to generate
texts that are intended to express and arouse emotions. The British physicist
performed this experiment a full thirteen years before the appearance
of Joseph Weizenbaum’s ELIZA, which is commonly —
and mistakenly — held to be the earliest example of computer-generated
texts. Dr. David Link constructed an emulator of the machine, and ran
Strachey’s original programme on it, which is preserved in his papers
held by the Bodleian Library in Oxford.
From a technical perspective, the Universal Machine that Alan Turing designed
theoretically in 1936 can be reduced to a problem of memory. It had to
be capable of writing, reading, storing, and deleting any data. For the
Manchester Mark I, the engineer Frederic Williams had modified cathode
ray tubes common in both warfare and commercial applications in such a
way that electronics repeatedly read and refreshed the 1280 picture dots.
The storage system evolved out of attempts to filter out certain parts
in the picture received from the world. In early radar, increasing improvement
of the sensing power brought problems with it, for stationary objects
like mountains and buildings reflected the pulses and irritated the operator
by generating irrelevant information. In “Moving Target Indication”
(MTI), the engineers succeeded to filter out of the uniformly recorded
data what was of interest. They displayed and temporarily stored the wave
form of echoes of successive pulses on a CRT whose signal plate was connected
to a video amplifier. Instead of the direct signal on the monitor, which
before had displayed the actual radar echoes received, the indicator generated
arbitrary symbols by marking moving targets. Photography and television
were touted as technologies that faithfully recorded reality. Radar, however,
broke the seeming unity of reality and its representation apart, because
it programmatically manipulated the image, and this can be regarded as
the “primal sin” of this technology. The rays received now
only represented the initial data for filtering, that is, the algebraic
calculation of the image. Slowly but surely, algorithms were beginning
to determine what was considered as real.
The combination of highly sensitive sensors and imaging produced by calculations
resulted, as of 1941, in the appearance of “angels” on radar
screens, which naturally astonished and baffled the operators. This was
what they called Doppler echoes in the clear air, when pilots flying past
could not identify the source. These signals hallucinated by the technical
system fanned the flames of discussions about unidentified flying objects
of extraterrestrial alien life forms in the 1950s. After the war, these
hallucinatory signs changed into symbols of nothing; pure signs that could
take on any arbitrary meaning — computer memory.
Computer Archaeology opens up a field in which theoretical and practical
aspects, immaterial procedures and their technical implementation refer
to and emerge from each other. The difference of execution, which
separates these symbolic apparatuses from other artefacts and consists
in their autonomous carrying out of almost endless sequences of instructions,
creates an opaque area between the input of the original data and the
incalculable moment in which the machine returns with the result, which
is not easily penetrated. The technical history of ideas cannot omit this
space of time and is forced to pass through the practical work of reconstructing
the apparatus and the operations performed on it.
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