Olivetti Programma 101

The Programma 101 was not the first progrmmable calculator, though in popular culture, it is considered to be the first. Actually, the first programmable stored-program calculator was the Mathatronics Mathatron 4-24 and 8-48 calculators. These were introduced and sold before the Olivetti machine came to market. The Diehl Combitron (and the SCM equivalent, OEM'd from Diehl) were amazing machines. The Combitron was invented by Stanley Frankel, one of the physicists on the Manhattan Project, and also the designer of the SCM Cogito 240 electronic calculator, as well as the Royal McBee LGP-30 "mini computer" (and a few other small computers). The Combitron was a microcoded architecture (the first microcoded electronic calculator), and loaded its microcode from a punched metal tape that encoded the microcode. The tape had two channels, one channel provided clocking, and the other channel coded 0's and 1's for the microcode load, which was read into a magnetostrictive delay like, and controlled the operation of the machine. Another magnetostrictive delay line contained the working registers of the machine. It was quite an elegant design. I have been in communication with Stanley Frankel's son, who has vivid memories of helping his Dad working on building the prototype of the Combitron in their home. They made visits to Germany to the Diehl plant to build a second, improved prototype, which Diehl then used as the basis for the building the production Combitron. The Programma 101 had a distinction of being the first calculator to have a simple and efficient built-in magnetic card storage device that allowed reading in programs and data, and writing them back out again. The Mathatron did not have a means for "offline" storage of programs, although it did use magnetic core memory for program storage, so programs would be retained during powered-off time. However, anytime a new program was desired, it would have to be entered by hand through "Learn Mode" program entry. The Combitron did provide ability to attach an external punched paper tape reader/punch which could be used to punch out programs on tape for later re-reading into the calculator (the delay line memories were volatile, meaning the content would be lost when the calculator was powered off), and could also be used to load data into programs automatically, as well as punch out the results of calculations. The Combitron was a great "front end" machine to small and medium-sized computer systems, where data could be pre-processed on the Combitron, then intermediate resulst punched onto tape, for input to a large computer for final data analysis. All of these machines are wonderful examples of the ingenuity and creativity of the early designs used in early electronic calculators. Rick Bensene The Old Calculator Museum http://oldcalculatormuseum.com