At 09:00 PM 9/10/98 +0000, you wrote:
>As far as I know, MotorOn instructs the drive to start spinning, some
>'dumb' drives do this right away, other drives with a bit of 'brains'
>only react on it, when a disk is detected in the drive, and keep
>still when not. When de-activated, most drives keep the disk running
>a few seconds after that, regardless of any software-controlled
>delays. If you permanently ground it, that means that a disk you put
>in the drive will start spinning right away, and will keep on doing
>so 'infinitely' as long as it's in the drive. If it solves your
>problem, you might do so, but it doesn't seem like a good idea to me.
I only shorted the MotorOn to test what happened, as to give a clue to what
could be wrong.
>The Ready-signal indicates whether the disk has reached 'normal
>operating spinning-speed' (5 times round / second), so normally, the
>drive should only be able to activate this, when the disk already is
>(MotorOn activated previously). I guess you kind of got this far.
I found the error tonight!
On the turbo R main board there are connections for two drives. Because it
was easier to solder, I used the connector for the B-drive to attach the PC
drive cable to. But some signals on the B-drive connector are only for the
B-drive (not equal to the A-drive signals).
The following signals are seperate for the A-drive and the B-drive:
- drive select
- disk change
- motor on
I knew about the first two, but until now never thought of the MotorOn.
Actually I was just about to insert an extra IC that could generate a
MotorOn signal when I saw the wires of DriveSelect and DiskChange coming
from the other connector and it struck me that doing that to MotorOn might
solve everything.
>It might be that you're just out of luck
>on this one, and that there's no way to get your drive to work with
>this Turbo-R floppy-controller.
It was actually the 4th drive I tried. First was a Sony, which didn't work
at all. Second was a Mitsumi, which loaded reasonable well, but had
troubles saving. Third was a brand that I forgot, which didn't work at all.
Fourth was success: the TEAC drive.
If I had known about the wrong MotorOn signal, I might have been able to
get the other 3 drives working as well.
Strange thing is that the Mitsumi apparently didn't need a MotorOn signal
to start spinning...
>But then I remembered something else that might do the trick. I don't
>know if this an issue here, but I will mention it. I've got a
>magazine artricle somewhere, I looked it up, and found this: some
>older HD drives determine DoubleDensity or HighDensity by looking at
>pin 2 of their connector. Practicly all newer drives do this by
>detecting the extra hole in HD disks, but some older drives need to
>be told by the FDC, how to go about. If this is so, pin 2 on your
>drive might need to be grounded (open = HD, grounded = DD).
The 235HF has jumpers for this: you can use either the HD hole or one of
several pins.
By the way, in the 235HF open means DD and grounded means HD. In the
Mitsumi drive it was like you described.
>'Officially' pin 2 is simply 'undefined', I'm not sure, but I think
>some drives use it to put a DiskChange signal on this pin, for
>instance.
I used it for DiskChange and put Ready on pin 34.
Thanks to everyone for helping me solve this!
If anyone ever needs info on changing a drive in a turbo R, please mail me.
I got a lot of experience from the many hours I spent testing, measuring,
soldering etc.
Bye,
Maarten
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