dillon@PAVEPAWS.BERKELEY.EDU (Matt Dillon) (06/08/86)
MMU -Memory Management Unit (either on the CPU board/chip or another co-processor. MAT -Memory address translator (a VAT with huge page sizes) VAT -Virtual address translator Additionaly, some processors support 'memory protection' via some internal registers which simply supply a 'range' of allowed addresses. The difference between this and a real MMU (MAT/VAT) is that it doesn't allow disjoint memory segments (or a limited number of disjoint memory segments) My personal opinion is that I wouldn't even think of implimenting UNIX without an MMU.... I have no desire to wait 5+ minutes for the machine to reboot every time a program crashes. -Matt
fnf@unisoft.UUCP (Fred Fish) (06/09/86)
In article <8606081922.AA03584@pavepaws> dillon@PAVEPAWS.BERKELEY.EDU (Matt Dillon) writes: > My personal opinion is that I wouldn't even think of implimenting UNIX >without an MMU.... I have no desire to wait 5+ minutes for the machine to >reboot every time a program crashes. Not to mention accumulating a reputation for having buggy system software everytime some bozo's application blows you out of the water. When the machine freezes up or goes berzerk at seemingly random times, the average non-computer user is going to blame Unix and the organization responsible for supplying it... -Fred
grr@cbmvax.cbm.UUCP (George Robbins) (06/09/86)
In article <8606081922.AA03584@pavepaws> dillon@PAVEPAWS.BERKELEY.EDU (Matt Dillon) writes: > > My personal opinion is that I wouldn't even think of implimenting UNIX >without an MMU.... I have no desire to wait 5+ minutes for the machine to >reboot every time a program crashes. > > -Matt Yes, and don't forget the hours needed to rebuild/veryify the filesystem after a program dropped little cookies on the blocks and inodes innocently cached in memory then written back onto the disk... --- Mommy, Mommy they built another computer without an MMU... That's ok Junior, sometimes things just happen that way... But when you grow up!!! -- George Robbins - now working with, uucp: {ihnp4|seismo|caip}!cbmvax!grr but no way officially representing arpa: cbmvax!grr@seismo.css.GOV Commodore, Engineering Department fone: 215-431-9255 (only by moonlite)