Bill Degnan billdegnan at
Thu Aug 12 10:39:34 CDT 2021

I would think Herb would have some valuable input, but I do know with the
SA800's there are a lot of jumpers, they vary based on the rev of the
board, and you want to be sure that the loading of the heads is not jumper
dependent.  NOTING that I am only being logical not technical.  I would
only look to cross jumpering related to the drive head control off the list
of possible causes.


On Thu, Aug 12, 2021 at 11:26 AM Jonathan Chapman via cctalk <
cctalk at> wrote:

> Does anyone have experience running the MTI MXV22M? It's a dual-height
> QBus card that emulates RX02 but uses a 5.25" 96 TPI drive. I've got a
> small heap of them and we're trying to get them going.
> When trying to format diskettes using the process documented in the
> manual, the drive selects for maybe a second then deselects, and we get a
> drive not ready error. The controller isn't using the ready line, as the
> SA-460 for which it is designed doesn't supply it. No traces physically
> connect to pin 34.
> Since we're close to out of ideas, we've also plugged in a pair of Shugart
> SA-800s, on the idea that maybe the MXV22M is close enough to the MXV22 to
> show some signs of life. It doesn't give a drive not ready error, and it
> will step the heads like it's really formatting, but never loads the heads.
> Happy for any input on this one!
> Thanks,
> Jonathan

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