Definition: IBM 650

IBM's first successful commercial computer. Introduced in 1954, the 650 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. See punch card.

The 650's internal memory was a fixed-head magnetic drum containing 2,000 10-digit words that rotated at 12,500 RPM. Magnetic disks, which IBM pioneered, were available to the 650 in 1956 (see RAMAC). See IBM 701, IBM 1401 and System/360.

At an IBM 650 Console (1960)

The author of this encyclopedia, Alan Freedman, was a punch card operator in 1960. However, he wanted a "high-tech" photo he could brag about so he had a fellow operator snap his picture at the computer's console. Directly behind are a punch card reader and magnetic tape drives. See punch card.