Re: Stepper Acceleration in RWTS

[martin_haye <martin.haye@gmail.com>]

On Dec 28, 7:51 pm, Sheldon Simms <wsspa...@gmail.com> wrote:
> ... If that's the case, then the whole idea of
> "accelerating" the motor is kind of silly even though the code may successfully
> seek to the correct track.

I can add that my own experience developing NakedOS involved
empirically determining values that would work, and that I found
acceleration to be definitely necessary. If I started out stepping to
fast, the stepper wouldn't move at all.

There were some mentions in Beneath Apple DOS (I think) about Shugart
specs, and I suspect Woz actually had access to technical docs for the
stepper and used a table computation to arrive at the acceleration/
deceleration values.

I'm fascinated to learn about POKEing new speed values in for newer
drives into DOS. That's so cool I have to try it with my IIc.

--Martin