🚀 go-pugleaf

>From JSol@RUTGERS Sun Dec 13 17:04:42 1981
Works Digest	       Monday, 14 Dec 1981       Volume 1 : Issue 44

Today's Topics:	  Limiting 68000 To Permit Demand Paging
			(Very Short Digest)
----------------------------------------------------------------------

Date: 9 Dec 1981 20:06:22-PST
From: decvax!watmath!idallen at Berkeley
To: decvax!ucbvax!works@Berkeley
Subject: Limiting 68000 to permit demand paging.

Re: Ian Merritt's comment on a "real implementation" of paging.

The observations of hardware deficiencies published in this digest
lead me to believe that a single 68000 can not be involved in a
non-restartable instruction when a page fault occurs, since there is
no way to preserve the internal state of the chip, service the page
fault, and resume.  I am led to think that a "real implementation"
must involve more than one processor, essentially leaving the 68000
stuck in mid-instruction while the second processor brings in the
missing page(s).  Some comments seemed to suggest that, even with this
dual-processor kludge, it was still necessary to restrict the use of
certain instructions.  This is the point I am unsure of.  I can not
see this restriction as being a good thing if it means that one must
avoid auto[increment|decrement] modes.  I guess I am asking, What
precisely is a "real implementation"?  -IAN!

------------------------------

End of WorkS Digest
*******************
-------