29 Jan
2011
29 Jan
'11
6:45 a.m.
Having not yet learned from the Twiggy floppy drive
fiasco that they
were not competent to design everything in house, Apple made their own
10MB hard drive for the Lisa 2/10 (later Macintosh XL), the Widget. The
HDA was either made by Apple, or by a vendor based on an Apple design.
It doesn't physically resemble any other 5.25-inch HDA I've ever seen.
That suprises me. I knew the elecrtronics was an Apple design, but I had
assumed they'ed used a standard HDA (much as the (floppy drive) Disk II
was claerly a Shughart chassis with an Apple PCB on it).
IWM = 'Integrated Woz Machibne', I
believe. Does anybody know if there's
only one form of it, or several?
Aside from being made in either a DIP or a PLCC, I don't think there are
any significant variants to it. I was under the impression it was sort-of a
single-chip version of the
logic on the Disk II controller board -- buty how close is it ot that
logic?
It has some added features and modes, but if you don't enable those, it
is mostly compatible with the Disk II controller.
Is it the same state machine, for example?
Probably.
Could you make a replacement using the know
schematics and ROM dump
from a Disk II?
No, because you wouldn't have the extra features and modes.