Re: [hatari-devel] Re: Hatari floppy drive detection with EmuTOS

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Le 16/01/2014 01:05, David Savinkoff a écrit :
----- Nicolas Pomarède wrote:
... the WD1772 doc
says it needs to count 6 revolutions (index hole) from the floppy drive
to determine when the spin up is good.

But my understanding about this is that if the drive is disconnected,
you will never receive the index pulse, so the revolutions counter will
stay at "0", spin up will never complete, and restore will never
complete too, because it needs spin up to complete first.

I just read parts of the WD1772 data sheet and noticed that the 6
revolution spin-up is an optional flag that You set for some instructions.

Thus, you must devise your own timeout for a non-existent drive.

Yes, that's why I think it would make more sense to test if a drive is avaible by just doing a "restore" command without spinup bit. This way, you just rely on moving the head and reading TR00 signal, no index hole involved.

I read that an Atari ST floppy drive spins without stopping if the
floppy index is not working. (search atari-forum for: magnetic switch)

As the counter will never reaches '6', this makes senses the motor never stops.


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