Re: Floppy handling

From: Marc Lehmann (pcg@goof.com)
Date: Wed Jun 21 2000 - 21:53:12 EST


On Fri, Jun 16, 2000 at 12:16:13AM +0100, Adam Sampson <azz@gnu.org> wrote:
> OT, I know, but this always struck me as strange: every Amiga I've ever
> owned or used works equally well if you disable the "drive click" (with
> various software patches). Why did this feature stay around after the A500?

The drive click could be disabled, the stepping could not. If you try to
"move the head" to track -1, modern floppies will ignore this command BUT
will update the disk change signal. I am not sure wether the pc floppy
controller can be told to do that, however :( I guess it will simply
refuse to step below track 0 when the trk0 signal is active.

BTW: older (very old) drives just bumped their head (very noisy) against
the physical mounting, damaging it after a few thousand tries. Thats why
it wasn't done by default.

On Mon, Jun 19, 2000 at 10:10:03PM +0200, Jes Sorensen <jes@linuxcare.com> wrote:
> No, no, no. The Amiga uses a pin on the floppy connector that
> indicates disk change to generate an interrupt ..... next?

Which amiga? The amigas original sold by commodore (a1000, a500, a2000,
a3000, a4000) certainly do not have this functionality, simply because
it makes no sense to poll the drive and have you interrupted after you
polled. It is alwass faster to poll the drive and just use the signal
directly.

-- 
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