6 Jun
1998
6 Jun
'98
4:25 p.m.
Ethan Dicks wrote:
There
was a UNIX box, made by Perkin-Elmer that had two 68000 processors
coupled to implement page faulting. When the main processor would fault,
the secondary would load the desired page into RAM and restart the
primary at the new page. Ugly. That's why Sun used the 68010 early on.
You access non-existent memory, get a page-fault trap, your kernel
figures out where to put the wanted memory and returns from the trap.
Your code never knows that milliseconds have elapsed.
Actually, I believe it was the original Sun 1 which used the double
68000s.
Perkin-Elmer did make a 68000 Unix box, the 7350. It actually could run
three diffent OS's:
Personal IRIX
Uniplus System 3
MicroXelos (Uniplus-derived SVR2)
Interestingly, the MicroXelos kernel was smart enough to know about the
68010. If you installed one in a 7350, it would use different trap
handling code.
Tony Eros (you still out there?) has my old one which was upgraded with
a 68010.
<<<John>>>