| Re: [hatari-devel] LED with empty floppy drives |
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Le 04/05/2014 19:48, David Savinkoff a écrit :
I'm curious to know how the floppy LED is implemented in the STF.
Is the LED connected to the M51017AP IC, or is it connected to
something else?
I don't know, would need to find schematic for this.
Note that the LED is connected to the M51017AP 'in use pin'
in the SF354.
Problem is that in the doc, we don't know how 'in use' is build, so
maybe different manufacturer had different meanings.
Note that the external double sided SF314 is probably very similar
to the SF354... and the LED stays on.
Maybe Atari TOS has a M51017AP 'in use' Bug for double sided disks.
Note that EmuTOS can be made without this bug.
Hatari may have to emulate when the floppy disk is busy by checking
the floppy disk bus lines to know when the LED is on.
Even with the SF354, I'm not sure the 'in use' led signal is only
related to activity on the bus line (do you mean bits transfer ?).
We can see that on normal operation (disk inserted), the led is on even
during the 1 sec spinup phase ; during this spinup, there's no activity
on the bus, except the INDEX signal on each round.
If led was related to index signal too, the it would be blinking very
fast during the spin up phase.