IBM 7090

IBM 7090

The IBM 7090 was the transistor's answer to the tube era: IBM took its 709 vacuum-tube flagship — itself the successor to the 704 — and rebuilt it in transistors so quickly that the engineers simply renamed the project 709-T, a name that slid into "seven-oh-ninety" when spoken. The first installation was December 1959; the result was six times the 709's speed (~100 Kflop/s) at half the rental, running the same 36-bit scientific architecture — and it used Stretch project's IBM 7302 core memory to do it.^[1]

The machine's real legacy is software. At MIT, the 7090 — later a doubled-power 7094 — ran CTSS (the Compatible Time-Sharing System) from 1961: the first practical timesharing system, the ancestor of Multics, and the platform where MAD and the command shell itself were born — every modern command line descends from the one Louis Pouzin wrote for CTSS. Batch-world shops ran IBSYS on the same hardware; the 7090 was the machine where interactive and batch computing first coexisted.^[2]

The voice of HAL

In 1961 an IBM 7090 at Bell Labs sang "Daisy Bell" — the first song performed by computer speech synthesis, programmed by John Kelly, Carol Lochbaum, and Max Mathews (whose MUSIC had already made the 704 sing). Arthur C. Clarke was visiting Bell Labs, heard it — and a decade later HAL 9000, dying in 2001: A Space Odyssey, sang the same song as its mind was unplugged. The 7090 is thus the only computer whose voice became cinema.^[3]

Where it sits

The 7090 completes the 701 → 704 → 709 → 7090/94 scientific line — the last and fastest of the 36-bit tube-born architecture before System/360 replaced everything. It's where the batch era ended: CTSS proved a computer could be a room you visited over a wire, and the 7090 was the room.

Check your understanding

• What did "7090" originally stand for?
• What ran on MIT's 7090/7094 that made it historic?
• What cultural first did a 7090 perform at Bell Labs in 1961?
• How did the 7090 compare to the 709 in speed and cost?