Burroughs and UNIVAC Mainframe Lineages

Burroughs Corporation and Sperry Rand's UNIVAC division were, along with IBM, two of the most prominent American mainframe manufacturers of the twentieth century, and the two companies eventually merged in 1986 to form Unisys. The Burroughs Large Systems Group built a family of large 48-bit mainframes using an unusual stack-machine instruction set with dense syllables, beginning with the B5000 in 1961, a design optimized for compiling ALGOL 60 programs with a single-pass compiler. Sperry Rand's UNIVAC 1100/2200 series, a family of compatible 36-bit systems that began with the UNIVAC 1107 in 1962, was a solid-state successor to the company's earlier vacuum-tube UNIVAC machines. Grouping the two families together reflects the corporate lineage that made them, since 1986, sibling product lines of the same company.