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Re: An USB interface for Disk2?



Quite a few interesting ideas here.

I'm not sure that the whole track approach would work all that well. For reading, you have to know the sector layout or at least the number of, and how to identify sectors, in order to determine when you have circled around and have completely finished reading the track. One you have done that, you might as well read and write sectors.

This implies implementing at least part of the RWTS in the micro-controller, which doesn't bother me, too much. However, copy protected SW may require a special RWTS implemenation in order to be read.

So far, high level analysis make me think that a modern micro-controller should have plenty of power to accomplish the job of the Disk II controller hardware and the RWTS, without significant additional HW assistance.

The USB mass storage option may be an interesting way to go, but I'm not particularly excited about delving too deeply into USB having spent some fustrating time at work trying to manage a project that involved an USB device interface. However, it may be worth the effort and some kind of translation from USB mass storage to what essentially is RWTS should be doable.


Regards,
Mike Willegal

Linards Ticmanis wrote:
Mike Willegal wrote:

Seems like with a little additional effort, a real
disk II could even be driven directly by one of those Apple II emulator
programs.


I think you would have to read whole tracks, let the emulator run on an
in-memory representation of the track, and then write it back in one go
when the emulator tries to move the head off that track (if it has
changed). Otherwise, I assume that latency would ruin any attempt to do
this.