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

From: John Lawson <jpl15_at_panix.com>
Date: Tue Dec 9 21:16:54 2003

On Tue, 9 Dec 2003, Eric Smith wrote:

> The part of the ST-506 disk emulation that's of most concern to me is
> whether anything needs to be done about write precompensation. The
> controller shifts the pulses on write to compensate for the peak
> shifts that happen on magnetic media when flux changes are recorded
> close together.



  Is it not true that the precomp circuits are driven by head position
info - thus the 'solid' version (emulation) of any drive would just be
permanently 'stuck' in one mode or the other would the controller care, or
even know, what track and cylinder the actual 'data' were coming from?

  I don't know if this would cause the emulator qua emulator to fail at
some perhaps subjective level - but I can't see where one would need to
actually legislate write precomp into a block of RAM.


 Cheers and Best of the Season


John
Received on Tue Dec 09 2003 - 21:16:54 GMT