Stopping the motor

I have a quite funny problem.

I just finished coding my first (and last?) demo and thought that I should at least put it on a floppy disk to wrap the project up. Since I'm running on an emulator that would be a virtual floppy, an adf-file.

I made a startup-sequence which simply starts my demo, and that works.

However, the (virtual) floppy driver motor is running when my demo starts and it does not stop running until I exit my demo... So it is emitting a (fake) motor sound all the time, ruining the music.

So, I thought that there must be a way to stop the motor. I've played around a bit with the DSKMOTOR bit of CIAAPRB register, but it does not seem to have an effect.

I do not really want to write a trackloader or something like that...

Any ideas of how my to stop the disk motor?

[Cylon]

Give the system a few seconds to finish disk handling before taking over the machine. then the motor will stop by itself.

Hm.. So there is no way of controlling the motor yourself?
Is there any way to at least poll for whether the motor is still running or not?

[Galahad/FLT]

Originally Posted by mekhall

I have a quite funny problem.

I just finished coding my first (and last?) demo and thought that I should at least put it on a floppy disk to wrap the project up. Since I'm running on an emulator that would be a virtual floppy, an adf-file.

I made a startup-sequence which simply starts my demo, and that works.

However, the (virtual) floppy driver motor is running when my demo starts and it does not stop running until I exit my demo... So it is emitting a (fake) motor sound all the time, ruining the music.

So, I thought that there must be a way to stop the motor. I've played around a bit with the DSKMOTOR bit of CIAAPRB register, but it does not seem to have an effect.

I do not really want to write a trackloader or something like that...

Any ideas of how my to stop the disk motor?

Try this:

lea $bfd100,a5
bset #7,(a5)
bset #6(a5)
bset #5(a5)
bset #4(a5)
bset #3(a5)

[phx]

Important in CIABRPB ($bfd100) are:

Bit 7: /MOTOR (active low)
Bit 6: /DSKSEL3 (active low)
Bit 5: /DSKSEL2 (active low)
Bit 4: /DSKSEL1 (active low)
Bit 3: /DSKSEL0 (active low)

Whenever you select a drive (transition of the select-bit from high to low) it will remember the state of the MOTOR bit.

So, to turn all drive motors off, I am using this code:

        lea     $bfd100,a0
        or.b    #$f8,(a0)
        nop
        and.b   #$87,(a0)
        nop
        or.b    #$78,(a0)
        nop

1. Set MOTOR-off bit and deselect all drives.
2. Select all drives, which makes them aware of the MOTOR-off state.
3. Deselect all drives again.

I tried the solution from phx, and it works great!

Thank you!

Now I can get peace of mind and release my demo.