7 Aug
2000
7 Aug
'00
7:35 a.m.
While there seems to be a fair amount of information
about the older apples,
i.e. ][, ][+, and the IIc+, I've been unable to find any menaingful
information on the web about the plain-old IIc. It has an external
connector to a floppy disk drive, but I've found no information about the
drive itself. The IIc+ has an external "intelligent" drive, and I'd like
to
know what that means, in this case, not to mention that I'd like to know
about the "intelligent" hard disk that attaches to the IIc+ via that same
connector, though perhaps not using the same protocol.
AFAIK, the IIc+ has the internal equivalent of a UniDisk 3.5, which was a
"normal" Apple 800K mechanism with a microprocessor-based daughterboard
added. It communicates with the IIc through a packet protocol, which is
called SmartPort. However, the actual disk controller hardware of the IIc+
is just the IWM chip, which is a slightly fancier single-chip version of
Woz's original disk controller.
The only "intelligent hard drive" that Apple made for hooking up to floppy
disk ports on their computers was the HD20. (Not the HD20-SC, which is SCSI.)
The HD20 is only supported on Macintoshes, and it's protocol is NOT the
same as SmartPort. I don't know any technical reason why it wouldn't be
possible to write a driver to use the HD20 on the IIc+, but I haven't heard
of anyone doing it.
There's also little definitive information about
the memory usage for I/O
and how (and how closely) they emulated the ][+ slot usage. They've
apparently memory mapped the keyboard, so I would also like to know where in
the memory map the keyboard lives.
AFAIK, the keyboard is encoded at $C000 and $C010, just like any other
Apple II. The shift and option keys might be wired to the extra button
inputs, just like the old "shift key mod" people did on earlier Apples.
I'm considering cutting a hole in the side of the
box to accomodate some
sort of I/O channel. I understand that there was an expander available from
a third party, but have little information about that. The slot I'd make in
the box would accomodate a 40-pin, or perhaps 50-pin inline cable connector.
Since I'd prefer to make an internally buffered I/O channel as opposed,
simply, to bringing out the CPU's signals, it would be useful to have some
information.
Any suggestions?
Well, my main suggestion would be that if you're trying to accomplish
something *practical*, you should just use a late-model laptop computer.
But if you're just doing this for fun, more power to you!