3 Nov
2013
3 Nov
'13
2:36 a.m.
On 2013-11-02 18:59, John Wilson wrote:
Someone (was it Emanuel maybe?) suggested doing the
emulation at the
level of the HD controller chip (I forget, is it an SMC part?) on the
RQDX3 board.
I'm not sure I can take credit for it, but we talked about it so many
times ;-)
Assuming you can find the data sheet, doing a
register-level
emulation might *really* loosen up the timing quite a lot (hundreds of
nanoseconds to respond). Plus then you'd be dealing with cooked bytes
instead of raw flux transitions so you might be able to put something
more useful on your SD card (like plain old .DSK files, so it'd be easy
to insert/extract files with the SD card plugged into another computer
w/o having to hack the low-level format).
I still think it is the easiest approach, but I went away from it, as
there are to many different controllers out there. So the version which
stores the flux transitions should be the most general, and would help
on pretty much every system which used MFM/RLL drives ...
Cheers