On Jul 25, 3:25 pm, PeterH <[email protected]> wrote:
> Not withstanding the ANS's similarity to the 9500, and the fact that
> some 9500s had a plug-in ROM which could be harvested for use in an
> ANS, installing such a 9500 ROM in an ANS will NOT convert it into a
> Mac.
The problem with using a Mac 9500 ROM in an ANS is that the interrupts
are hard wired in both machines and they're hard wired a little
differently in the ANS than they are in the 9500. This is documented
in the Hardware Developers Note for the ANS, although the actual
document may have a different name. It's been a long time since I
looked at this stuff.
If one could reprogram the ROM of the 9500 to expect the interrupts
for the various devices in the proper places, then the 9500 ROM could
be made to work in the ANS. However, one would still not have
support for the on-board F&W SCSI, nor the built-in video, both of
which would require drivers either in extensions or in the ROM. It
might be a fairly simple job for a Forth educated person. I'm not
that person.
One other interesting tidbit about the ANS is that it demonstrates
that the Bandit PCI controller and associated arbiter chip has support
for at least five devices. The 9500 puts three PCI slots on each
Bandit, and puts Grand Central on one Bandit for four PCI devices on
one Bandit and three on the other. The ANS has Grand Central, six
PCI slots, two PCI-SCSI chips, and a video card equivalent, for ten
PCI devices total, or five per Bandit. This, incidentally, is also
why the interrupts are arranged differently.
Jeff Walther
Jeff Walther
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