Olivetti Programma 101 Art Installation

"The problem with conspiracy theories is that some of them are true" (anonymous)

Last week I found an Olivetti office calculator thrown away in a container, and when I plugged it in, the broken display suggested alphanumeric characters.

This sparked an idea: a fictional story where an Olivetti engineer decides to spread a certain message through the calculator's diagnostic mode. What message could an Olivetti engineer disseminate? How about the conspiracy theory behind the Programma 101 computer?

The Olivetti Programma 101, also known as Perottina or P101, was the first commercially produced desktop computer. Its memory had 10 registers: three for operations (M, A, R); two for storage (B, C); three for storage and/or programming (assignable as needed: D, E, F); and two for programming only. The P101 was programmed in a kind of assembly language and allowed programs to be stored on magnetic cards.

In the 1960s, the P101 had strategic military importance. In fact, it was used by NASA for the Apollo program and also by the Air Force to determine the coordinates of the B52 bombs during the Vietnam War.

# Instruction Set of the Olivetti Programma 101

Sum
+
A = A + Chosen Register (hereinafter "CR")
Subtraction
-
A = A - CR
Multiplication
x
A = A * CR
Division
:
A = A : CR
Square root
√
A = sqrt(CR)
Absolute value
A ↕
A = abs(A)
Transfer from M
↑
CR = M
Transfer in A
↓
A = CR
Exchange with A
↕
A = CRCR = A
Decimal part of A in M
/ ↕
M = A - abs(A)
Clear
*
CR = 0
Print
♢
Print the chosen register
Vertical spacing
/♢
Print a blank line
Stop
S
Stop the computer to let the user introduce data in the M register or to use the machine manually as a calculator
D-R exchange
RS
Store the D register temporarily in the R register; this is a special instruction used in multi-card program to save data from the deletion that happens while reading a new card

This is where the conspiracy starts. There were two suspicious deaths at Olivetti, the theft of a P101 prototype, and a hostile takeover bid by General Electric.

For this electronic art installation, I extracted the calculator's printing module, connected the module's motor to an L298 bridge, and connected the module and a display to an Arduino UNO R4 minimal. The conspiracy story of the Programma 101 is then told under the limitations of a calculator display: using 6 numeric digits.

Parts used

Olivetti printing module

Arduino UNO R4 Minima

Hbridge L298N

DC female jack

HT1621 numeric display

Switch

It may be a somewhat absurd project, but it's satisfying to rescue electronics from the trash to tell an exciting story.

Video

References

https://www.inexhibit.com/case-studies/olivetti-programma-101-at-the-origins-of-the-personal-computer/

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