Editing Burroughs Large Systems (section)

{{Short description|Range of mainframe computers in the 1960s and 70s}}
The '''Burroughs Large Systems Group''' produced a family of large [[48-bit computing|48-bit]] [[mainframe computer|mainframes]] using [[stack machine]] instruction sets with dense [[Syllable (computing)|syllables]].<!-- On the B5000 there are 4 types of syllables, only one of which has an opcode, and on the B6500 an instruction may have multiple syllables. [[instruction syllable]] is a redirect to [[opcode]]. --><ref group=NB>E.g., [[12-bit syllable]]s for B5000, [[8-bit syllable]]s for B6500</ref> The first machine in the family was the B5000 in 1961, which was optimized for compiling [[ALGOL 60]] programs extremely well, using single-pass compilers. The B5000 evolved into the B5500 (disk rather than drum) and the B5700 (up to four systems running as a cluster). Subsequent major redesigns include the B6500/B6700 line and its successors, as well as the separate B8500 line.

In the 1970s, the [[Burroughs Corporation]] was organized into three divisions with very different product line architectures for high-end, mid-range, and entry-level business computer systems. Each division's product line grew from a different concept for how to optimize a computer's instruction set for particular programming languages. "Burroughs Large Systems" referred to all of these large-system product lines together, in contrast to the [[COBOL]]-optimized [[Burroughs Medium Systems|Medium Systems]] (B2000, B3000, and B4000) or the flexible-architecture [[Burroughs Small Systems|Small Systems]] (B1000).