jason@cs.utexas.edu (Jason Levitt) (01/16/90)
I'm trying to put a 68851 PMMU chip in to a Macintosh II.
When I put the chip in, the machine will not boot.
The chip is an early mask version denoted by "XC". It reads:
XC68851RC16
9B87D8724
In addition, I believe the Macintosh II logic board is quite
early because there are 12 little chips just south of the NUBUS
slots, rather than one LSI chip. Is this correct?
Is the problem with the early logic board version, or the
early PMMU mask, or both?
Does anyone know the serial #'s of bad logic boards, or mask
#'s of bad PMMU chips?
Will Motorola or Apple let you trade in the bad chips or boards?
I'll summarize answers to the net....
---Jason
-----
Jason Levitt P.O. Box 49860 Austin, Texas 78765 (512) 459-0055
Internet: jason@cs.utexas.edu | "Disneyland exemplifies the essence of
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| -Ronald Reagan [1990]gft_robert@gsbacd.uchicago.edu (01/17/90)
In article <1076@gort.cs.utexas.edu>, jason@cs.utexas.edu (Jason Levitt) writes... > > I'm trying to put a 68851 PMMU chip in to a Macintosh II. >When I put the chip in, the machine will not boot. [...] I read in MacWeek a month or so ago that some early Mac II logic boards would not work correctly with the PMMU. I think Apple will replace the board for free for those machines. Sorry, I don't know which numbers/dates they are. Robert ============================================================================ = gft_robert@gsbacd.uchicago.edu * generic disclaimer: * "It's more fun to = = * all my opinions are * compute" = = * mine * -Kraftwerk = ============================================================================