Maarten ter Huurne <[EMAIL PROTECTED]> wrote:
> > >From an old PC, I got the following drive:
> > > TEAC FD-235HF
> >
> > Sounds familiar somehow, I think it's a 720 K type...
>
> No, it's a 1.44MB (HD) drive.
>
Aah, so:
Teac FD-235F = 720 K
Teac FD-235HF = 1.44 MB
(at least we know that then)
> I am connecting it to an FS-A1GT (turbo R), which needs both Ready and
> DiskChange.
>
Ai, that might be difficult indeed...
> But I still have some troubles with this drive. Symptom: drive will
> not spin and the LED only flashes a few times.
> I think the problem is somewhere in the order of the Ready and
> MotorOn signals. It seems the turbo R won't give MotorOn until it has
> received Ready and the drive won't give Ready until it has received
> MotorOn. Is this possible?
> I came to this idea because I noticed that short-circuiting the
> MotorOn signal made the drive work, as did short-circuiting the Ready
> signal.
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.
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 own a MSX2+ myself, with the same floppy-controller (TC8566) as in
the Turbo-R, and have hooked up quite a number of drives to it in
past years. My impression is, that this FDC is a bit more 'choosy'
when it comes to whether a drive 'will do' or not, I suspect it's got
to do with signal timings (as you mentioned). As a result, some older
drives can't get to work with it, most newer (new) drives are no
problem. But, IF they work, it usually works far more reliable, far
less 'strange disk errors'. 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.
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).
'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.
If all this still doesn't help, I suggest you forget about hooking
this Teac FD-235HF up to a Turbo-R....
Greetings,
Alwin Henseler ([EMAIL PROTECTED])
http://www.twente.nl/~cce/index.htm
http://huizen.dds.nl/~alwinh/msx/supturbo
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