[Coco] Thought

Eric J. Rothfus eric at rothfus.com
Fri Sep 24 12:21:45 EDT 2004


> (1) I would imagine the timing would have to be fairly tolerant for seeks
> given the variable step times for different drives???

They sure are.  And I think you're right, that an appropriate
buffer would allow you to deal with any hiccups at the sector
level.

> But if you assume that the seek time(1) of a floppy drive is always
> going to be enough to cover the latency of starting a USB transfer, you...

This is where I wonder.  Although the interface circuit would
be easily able to issue the USB request within a usual seek
time, what concerns me is the PC responding to the request
quickly.  Granted, if a program was written that would
stay resident (ie - not have to be swapped in) and if the USB
was quiet I wouldn't worry about it.  But that adds complication
to the PC side.

Bottom line is that the smaller the interface circuit, the
more "real-time" the PC application needs to become.  I think
that there is a healthy balance as you were suggesting with
an "appropriate" buffer and circuit.

THEN...I could imagine a fairly simple application (which I have
been meaning to write) that would allow the vintage machine
to select from a library of programs/images.  The circuit/app
could respond to these requests and load the appropriate image.

Anyway, back to my "paying" job...
But this is a fun distraction.

Eric




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