Disk hardware emulation, was Re: Grandfather system RTE6/VM?

From: Tony Duell <ard_at_p850ug1.demon.co.uk>
Date: Wed Dec 10 23:54:48 2003

>
>
> Something else that would be nice to be able to do with this sort of
> hardware would be the ability to read an arbitrarily formatted real
> disc drive. The MFM drives in Xerox 6085's and 8010's have 'interesting'
> sector formats that can't be read with normal controllers.

Great minds think alaike (and so do idiots like me). I suggested this in
one of my other messages. It wouldn't be too much work -- the data
handling part of the emulator/interface is much the same. What you need
to do is start sampling the data output from the drive on an index pulse
and carry on until the next index pulse (a couple of D-types and a bit of
logic here). And have some thingy to select the heads (and sections of
the emulator RAM) one after the other, then move the drive onto the next
cylinder. THose functions can be done with a microcontroller.

It would certainly be useful to do this for machines that can't low-level
format the drive (either due to hardware limitations, or due to lack of
suitable software).

-tony
Received on Wed Dec 10 2003 - 23:54:48 GMT