silverdr_at_wfmh.org.pl
Date: 2008-10-14 20:10:09
On 2008-10-14, at 18:00, Greg King wrote:
>> The next delay is the one for stepping the head. As I don't use
>> any head-
>> stepping at all, I simply removed all routines. But, Gideon's
>> 'floppy
>> drive' does act on the state of the outputs of the 6522; and so, I
>> need at
>> least the routines that output the signals for the stepping motor.
>> There is a routine for fast-stepping the head and one for slow-
>> stepping.
>> The actual decision is made at $FA0E where the number of steps is
>> compared with MINSTP ($0064). MINSTP is filled with the value $C8
>> = 200
>> at position $F2A4. Whatever the original input is, at $FA0E,
>> register A
>> is a number where bit 7 _always_ = zero. And therefore, A never
>> can be
>> greater then $C8; and thus, the fast-stepping routine never is
>> executed.
>>
>> Or, am I wrong?
>
> My reply is months late; but, I must ask:
>
> Doesn't 200 steps move the head by 100 tracks? Why would that code
> be on
> machines that have less than 100 tracks?
Maybe that was a quick'n'dirty way of simply disabling the routine in
question?
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