On 2019-11-05 13:45, rescue wrote:
Been away for some time from the mailing lists.... getting back into
my classic gear again....
I have two of these Qumetrack 542 drives.
While testing my 360K drive collection (8 drives.... I must be
slacking :-) ...), 2 worked, 4 had issue (resolved with a good head
cleaning), and 2 (both of the Qumetrack 542 drives (I have two of
them)) have mixed results. My testing is on a Tandy 2500SX/33 using
the Tandy straight through cable and with the drives set do DS0.
I seem to have no issue with Dunfield's testfdc (using testfdc/x a:)
with these drives, doing SS and DD and getting 'pass' from testfdc.
I
can also use his imagedisk program, go to the alignment section, and
I
can track the drive properly up an down the disk.... it is just DOS
that can't seem to do it.
However, when I do a format a:, the drive will format through the 40
tracks, then instead of the heads returning to track 0 quickly, they
do these small stepping 'bursts' and DOS times out saying
failure.....
it probably would have worked if DOS would wait 10 seconds or more
for
the drive to move to track 0.
I've never seen behavior like this. I even tried an external power
supply in case the Tandy one wasn't up to driving the full height
floppy drive due to an aging marginal supply, but that didn't help
anything.
I've now also had one of them shut down the power supply (a shorted
tantalum cap I'm sure).
I've looked through the manual on the drive, I've tried the HM, HS,
and no jumper setting for stepper motor power, same results in all
cases.
I'm trying too determine if these drives are good. I'm planning on
using them in a Tandy Model III that is upgraded internally to a
Model
IV, but I feel these are basic drives and should work in DOS fine
too.
I hope someone has a clue, as I'm tapped out of them currently.
Well, For reference... I figured it out.
Apparently the newer system (Tandy 2500SX/33 (386SX cpu)) has to fast
of a step time.
I found a program called flopparm.com and teststep.com which are part
of FPLKIT11.ZIP.
By using:
flopparm custom=10,15,15,8
I was then able to format a disk using DOS format.
I won't be using the drive on this system, and it will be being used
likely in a TRS-80 Model III, so I'd imagine the older system won't be
as aggressive on the timings as the 386SX is and it won't be an issue.
So, both of my drives are confirmed good (well, after I replaced the
shorted tantalum on one of them).
-- Curt
Thanks,
-- Curt
