Bull Gamma 60

Bull Gamma 60
Bull Gamma 60 at SNCF in Auteuil, France, 1960
DeveloperCompagnie des Machines Bull
TypeLarge-scale mainframe computer
Generation2
Release date1960
Introductory price10M Francs (1960, about $18M USD in 2023)
Units sold17
Operating systemGGZ, GGU
CPUTransistorized, distributed and multi-threaded. Up to 25 Processing Units. 24-bit words with 1 to 4 words data types. @ 100 kHz
MemoryCentral memory: 32 kwords (core memory). Up to four drum memory extensions (25 kwords each).
StorageUp to 48 magnetic tape readers
InputMagnetic tape, punched cards, paper tape, teletypes
Power200-400 kVA
DimensionsTypically 3000-4000 sq.ft
PredecessorBull Gamma 3
SuccessorGE-600 series

The Bull Gamma 60 was a large transistorized mainframe computer designed by Compagnie des Machines Bull. Initially announced in 1957, the first unit shipped in 1960. It holds the distinction of being the world's first multi-threaded computer, and the first to feature an architecture specially designed for parallelism.

The Gamma 60 spearheaded numerous groundbreaking technologies during the early 1960s, notably in multi-programming, utilizing tools that were still in their nascent stages. Upon its release, its architecture garnered significant attention among machine designers, becoming a subject of study alongside contemporary supercomputers and being cited as an example for progress in computer design.

Despite its innovations, the Gamma 60's large footprint (close to 4000 sq.ft), high cost, energy consumption, and complexity ultimately resulted in limited commercial success, with about only twenty units sold worldwide. Its main competitors included the IBM 7070, 7090, and 7030 "Stretch". The last Gamma 60 remained in service until 1974.