Editing Memory segmentation (section)

====B5000, B5500 and B5700====
{{see also|B5000 instruction set|Burroughs large systems descriptors#B5000, B5500 and B5700}}
Words in the [[Burroughs Large Systems#B5000, B5500, and B5700|B5000, B5500 and B5700]] are 48 bits long.<ref name=oper>{{Citation
 |     title = The Operational Characteristic of the Processors for the Burroughs B 5000
 |        id = 5000-21005A
 |   edition = A 
 |      year = 1962
 |       url = https://bitsavers.org/pdf/burroughs/LargeSystems/B5000_5500_5700/5000-21005_B5000_operChar_1963.pdf
 |  location = Detroit
 | publisher = Burroughs
 }}
</ref> [[Burroughs large systems descriptors|Descriptors]] have the uppermost bit set in the word. They reside in either the Program Reference Table (PRT) or the stack, and contain a ''presence bit'' indicating whether the data are present in memory. There are distinct data and program descriptors.<ref name=oper />{{rp|pages = 4{{hyp}}2-4{{hyp}}4}}