12 Aug
2021
12 Aug
'21
11:03 a.m.
Pretty sure it's not a SA-800 problem, that was just something we tried in the course
of running out of other ideas. These controllers are meant to talk to SA-460 or Tandon
TM100-4 96tpi 300 RPM drives ("quad density").
I did of course force head loading on drive select, which does make the SA-800s load the
heads when selected. Still nothing written to the diskette, though.
I'm sure the SA-800s are good as they're my main test bench drives. They've
been extra-special-exactly aligned so I can interchange media with Mike Douglas' FDC+
Altair compatible disk controller, which has very strict index timing demands.
Coincidentally, these are the drives I bought from you, Bill, when you moved out of the
Wilmington building! The ones that had the locked steppers.
Thanks,
Jonathan
??????? Original Message ???????
On Thursday, August 12th, 2021 at 11:39, Bill Degnan via cctalk <cctalk at
classiccmp.org> wrote:
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.
Bill
On Thu, Aug 12, 2021 at 11:26 AM Jonathan Chapman via cctalk <
cctalk at classiccmp.org> 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