IBM 650

IBM's first successful, commercial computer. Introduced in 1954, it read data from punch cards and magnetic tapes. By the end of the 1950s, there were more than 1,500 units installed, making it the most widely used computer in the world. The 650 added high-speed computational ability to the punch card data processing that was the norm in every large enterprise in those days.

The 650 used a fixed-head magnetic drum that rotated at 12,500 RPM for its internal memory from 1,000 to 2,000 10-digit words. Magnetic disks, which IBM pioneered on its 305 RAMAC, were made available to the 650 in 1956. See IBM 1401 and System/360.

IBM 650

This photo taken in 1960 shows the author of this publication, Alan Freedman, sitting at the console. Directly behind him is a punch card reader, and behind that, the magnetic tape drives.

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(computer)

IBM 650 - A computer, produced ca. 1955 and in use in the late 1950s, with rotating magnetic drum storage and punched card input. Its memory words could store 10-digit decimal numbers and each instruction had two addresses, one for the operand and one for address of the next instruction on the drum. SOAP was its (optimising) assembler. Languages used on it included BACAIC, BALITAC, BELL, CASE SOAP III, DRUCO I, EASE II, ELI, ESCAPE, FAST, FLAIR, FORTRANSIT, FORTRUNCIBLE, GAT, IPL, Internal Translator, KISS, MITILAC, MYSTIC, OMNICODE, PIT, RELATIVE, RUNCIBLE, SIR, SOAP, Speedcoding, SPIT, SPUR.