steelie@pro-charlotte.cts.com (Jim Howard) (11/21/88)
Everyone, please refrain from flaming me! I know direct
hardware "hacks" tend to get frowned upon...
Im attempting to simply move the disk head 1 track toward
the center of the spindle.. Here's how Im doing it..
bclr #1,$bfd100
** ^^specify direction
bclr #7,$bfd100 ;turn on the motor
bclr #0,$bfd100 ;first half of step pulse
bset #0,$bfd100 ;second half of step pulse
Now, why doesnt this do anything? Im not exactly sure whether
I am supposed to set up all the bits, and turn on the disk DMA,
or what.. The hardware reference manual is VERY ambiguous.
Remember, Im not trying to read data from the disk, Im just
trying to move the head. I have to figure out how to move
the head before I can read data anyway..
Thanks
UUCP: ....!crash!pro-charlotte!steelie | Pro-Charlotte - (704) 567-0029
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INET: steelie@pro-charlotte.cts.com | Log in as "register"ditto@cbmvax.UUCP (Michael "Ford" Ditto) (11/22/88)
In article <3593@crash.cts.com> steelie@pro-charlotte.cts.com (Jim Howard) writes: >Everyone, please refrain from flaming me! I know direct >hardware "hacks" tend to get frowned upon... Ok, flame withheld, but you'd better have a darn good reason... :-) >Im attempting to simply move the disk head 1 track toward >the center of the spindle.. Here's how Im doing it.. > > bclr #1,$bfd100 >** ^^specify direction > > bclr #7,$bfd100 ;turn on the motor > bclr #0,$bfd100 ;first half of step pulse > bset #0,$bfd100 ;second half of step pulse Did you select a drive? Something like (pardon my C): ACIAB->prb |= 0x78; /* Unselect all drives */ ACIAB->prb &= ~0x80; /* Turn on the motor (if desired) */ ACIAB->prb &= (0x08<<drivenum); /* Select the one we want */ ACIAB->prb &= ~0x02; /* Specify direction */ ACIAB->prb &= ~0x01; /* First half of step pulse */ ACIAB->prb |= 0x01; /* Second half of step pulse */ I think I have the order correct, but I'm sure someone will correct me if I don't. >Now, why doesnt this do anything? Im not exactly sure whether >I am supposed to set up all the bits, and turn on the disk DMA, Ouch! (DMA is for the actual transfer of bits to/from memory, and you'd better tell it where to start reading and writing before you activate DMA). -- -=] Ford [=- "The number of Unix installations (In Real Life: Mike Ditto) has grown to 10, with more expected." ford@kenobi.cts.com - The Unix Programmer's Manual, ...!sdcsvax!crash!elgar!ford 2nd Edition, June, 1972. ditto@cbmvax.commodore.com