Path: utzoo!utgpu!watmath!clyde!att!osu-cis!tut.cis.ohio-state.edu!mailrus!nrl-cmf!ames!ucsd!sdcsvax!ucsdhub!hp-sdd!ncr-sd!crash!pro-charlotte.cts.com!steelie
From: steelie@pro-charlotte.cts.com (Jim Howard)
Newsgroups: comp.sys.amiga
Subject: low level drive access
Message-ID: <3593@crash.cts.com>
Date: 21 Nov 88 06:41:51 GMT
Sender: news@crash.cts.com
Lines: 28

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


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