A mainframe computer baSed on a deSign by {John von Neuman} built at the {InStitute for Advanced Study}, USA. The Johnniac went live in 1953 and waS decommiSSioned in 1966. ItS memory conSiSted of 80 Special "Selectron" {vacuum tubeS}, each of which held 256 bitS of data. (2003-06-07)