4 ms·
The old Burroughs systems (up to at least the B7700) didn't really have MMUs in the traditional sense - their descriptors only reserved 20 bits for (word addres
by Taniwha 4y ago
The old Burroughs systems (up to at least the B7700) didn't really have MMUs in the traditional sense - their descriptors only reserved 20 bits for (word addresses) so they were limited to ~6Mb of addressing - not a big deal when we had paid over a US$ million for 1.5Mb of B6700 core, no one could have afforded more - they paged segments (much as a 432 would have) and also supported segments chunked into 256 word chunks for large arrays (at the cost of an extra memory access per lookup).