Editing Memory segmentation (section)

====B6500, B7500 and successors====
{{see also|Burroughs B6x00-7x00 instruction set|Burroughs large systems descriptors#B6500, B7500 and successors}}
Words in the B6500 and its successors have 48 bits of data and 3 tag bits.<!--4 bits in later machines?--><ref name="b6500-ref-man">{{cite book |url=http://www.bitsavers.org/pdf/burroughs/LargeSystems/B6500_6700/1043676_B6500_RefMan_Sep69.pdf |title=B6500 Information Processing Systems Reference Manual |publisher=Burroughs |date=September 1969}}</ref>{{rp|page=2{{hyp}}1}} The tag bits indicate the type of data contained in the word; there are several descriptor types, indicated by different tag bit values.<ref name="b6500-ref-man" />{{rp|pages=6{{hyp}}5-6{{hyp}}10}} Control words and descriptors reside in the Saguaro stack. Array segments may be paged.

The line includes the B6500, B6700, B7700, B6800, B6900, B5900, the A-series Burroughs and Unisys machines, and the current Clearpath MCP systems (Libra). While there have been a few enhancements over the years, particularly hardware advances, the architecture has changed little. The segmentation scheme has remained the same, see [[Virtual Memory#Segmented_virtual_memory|Segmented memory]].