Programma 101

The Programma 101 was a printing programmable calculator manufactured by Olivetti in 1965. It is regarded as the first personal computer produced by a company (that is, a desktop electronic calculating machine programmable by non-specialists for personal use). A futuristic design for its time, the Programma 101 was priced at an almost affordable $3,200 (versus $25,000 for a PDP-8).

Capabilities

The Programma 101 was able to calculate the basic four arithmetic functions (addition, subtraction, multiplication, and division), plus square root, absolute value, and fractional part. Also clear, transfer, exchange, and stop for input. There were 16 jump instructions and 16 conditional jump instructions. 32 label statements were available as destinations for the 32 jump instructions and/or the four start keys (V, W, Y, Z).

Each full register held a 22-digit number with sign and decimal point.

Its memory consisted of 10 registers: three for operations (M, A, R); two for storage (B, C); three for storage and/or program (assignable as needed) (D, E, F); and two for program only (p1, p2). Five of the registers (B, C, D, E, F) could be subdivided into half-registers, containing an 11-digit number with sign and decimal point. When used for programming, each full register stored 24 instructions.

It printed programs and results onto a roll of paper tape, similar to calculator or cash register paper.

Stored programs could be recorded onto magnetic cards approximately 10cm x 20cm. Each card could be recorded on two stripes. All ten registers were stored on the card, thus allowing programs to use up to ten stored 11-digit constants.

Programming was similar to assembly language, but simpler, as there were fewer options. It directed the exchange between memory registers and calculation registers, and operations in the registers.

The program to calculate logarithms occupied both stripes of one magnetic card.

Construction

All computation was handled by discrete devices (transistors and diodes mounted on phenolic resin circuit card assemblies), as there were no microprocessors and integrated circuits were just beginning. It used an acoustical delay line memory with metal wires as a data storage device. Magnetostriction transducers inside an electromagnet attached to either side of the end of the wire. Computer bits entering the magnets caused the transducer to contract or expand (based on binary value) and to twist the end of the wire. The resulting torsinal wave moved down the wire. A piezoelectric transducer converted the bits to an electronic signal that was then amplified and sent back at the beginning with a delay time of 2.2 milliseconds. Typically, many bits would be in transit through the delay, and the computer counted them by comparing to a master clock to find the particular bit it required. Delay line memory was far less expensive and far more reliable per bit than flip-flops made from vacuum tubes, and yet far faster than a latching relay. Computer programs went on plastic cards with a magnetic coating on one side and an area for writing on the other. V, W, Y, and Z stripes on each end of a card enabled it to store two programs.

History

It was designed by Olivetti engineer Pier Giorgio Perotto in Ivrea.

The styling, attributed to Marco Zanuso but in reality by Mario Bellini, was ergonomic and innovative for the time, and earned the company the Industrial Design Award.

Developed between 1962 and 1964, it was launched for the first time at the 1964 New York World's Fair, attracting major interest. 40,000 units were sold; 90% of them in the United States where the sale price was $3,200.

Hewlett-Packard had to pay about $900,000 in royalties to Olivetti after using some of the solutions adopted in Programma 101 in the HP9100.

A futuristic design for 1965, the Programma 101 could be regarded as the first personal computer produced by a company (not a personal computer as it is understood today, but a calculating machine, programmable by non-specialists, and intended for personal use, at the almost-affordable price of $3,200.)

The 101 is mentioned as having been used by the US Air Force to compute coordinates for ground directed bombing of B-52 Stratofortress targets during the Vietnam War. [cite book
last = Rotter
first = Andrew, ed.
title = Light at the end of the tunnel : a Vietnam War anthology / edited by Andrew J. Rotter : p. 280, Shawcross: Bombing Cambodia--A critique
year= 1991
location= New York
isbn = 0312045298] .

References

External links

* [http://www.silab.it/frox/p101/ introductory descriptions of P-101]