[HECnet] 2.11BSD

Paul_Koning at Dell.com Paul_Koning at Dell.com
Tue Dec 18 06:45:40 PST 2012


On Dec 17, 2012, at 6:01 PM, Johnny Billquist wrote:

On 2012-12-17 23:50, Boyanich, Alastair wrote:
...
2) Was 2.11BSD ever ported to other platforms? Given the age/era, I'm
curious about 8088/8086/NECv20/80286 given the banked memory models used
and looking at the 8088/8086 XENIX disassembly.

Nope. That would not have been 2BSD then. And since the PDP-11 don't even have banked memory, it would probably cause some headaches to port 2BSD to something like 80286 or other similar machines.
To make it clear - the PDP-11 have a very normal MMU with pages.

Semi-normal.   It's rather unusual in that it has a paged MMU with page address granularity different from the page size (64 bytes vs. 8k bytes).   Most architectures have those two match, that avoids an adder -- consider VAX or MIPS or Alpha.

	paul



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