Re: Some questions about a2 upgrading

[david@uow.edu.au (David Wilson)]

Roy and/or Janet Miller <millers@inetnebr.com> writes:
>There were multifunction cards for the II, however, the ones that I've used
>"pretended" to be in different slots for each function. Given that the "driver"
>for a II card was in ROM on that card, and was limited to (I think) 256 bytes,
>I'm not sure that your idea would work - but it would be interesting.

With the introduction of Smartport, the Apple // finally had an interface
that would support multifunction cards. Unfortunately, only block devices
(disks) are supported by any operating system I know of. The character
device interface could replace the BASIC & Pascal 1.1 interfaces under GS/OS
but not under ProDOS 8. Using IOSTB and bank selection it is quite easy to
support a massive firmware interface with the 256 byte IOSEL just calling
routines in the large ROM.

With a common Super I/O chip you should be able to make a card with support
for 2 (or possibly 4) 3.5/5.25" floppy disk drives, a parallel printer port,
two serial ports, two IDE channels. Provided the disk drives got power
externally it should not tax the Apple // power supply too much.
--
David Wilson  School of IT & CS, Uni of Wollongong, Australia