David Wilson wrote:
The trick is, how does the card interoperate with the existingkeyboard? Does it disable it or try and work alongside it?
You're right of course, I wasn't considering the practicality of doing any devices other than those traditionally available on Apple II expansion cards. So yes, a keyboard on an expansion card is a problem - a small adapter plugged into the keyboard connector on the motherboard is not so much of a problem.
The most flexible design for a USB card would be to make it appear as a SmartPort controller as this protocol already supports block (disklike) and character (keyboard/mice/etc) devices. Unfortunately there has never been a SmartPort character device (AFAIK) and no existing program is going to look for a mouse or a keyboard on a SmartPort. This would not be a problem for GS/OS with its loadable drivers but would be a killer for the II/II+/IIe market.
I know *very* little about the apple, other than the basic architecture, so you may well be right.
I was thinking along the lines of an (expensive) FPGA solution that was capable of emulating a number of expansion cards, with possibly a USB host chip on it for connection to USB mice etc.
What I've always thought would be useful is a device that looks like a floppy disk drive from one side and connects to the PC via USB on the other. Then, a PC program 'serves' disk accesses from the Apple/TRS-80/etc. That way, you could store a complete library of floppy disk images on the PC yet run them on the real hardware without the need to transfer to real floppy disks etc.
Regards, -- | Mark McDougall | "Electrical Engineers do it | <http://members.iinet.net.au/~msmcdoug> | with less resistance!"