Subject: Re: Floppy code

From: [email-masked] (Brad Pepers)

> > timings in device drivers? I need to be able to do very short delays
> > (3ms) in the floppy driver I have written. From what I understand the
> > timeout() routine can do at best a delay of a few ticks which at 100
> > HZ is somewhere around 20-30ms.
> 
> Hm, how accurate do those delays have to be? Would you be able to
> sleep on the event, or would you have to poll? Problem is wakeup on
> CIA-A would generate a pretty lowlevel interrupt, and you'd probably
> not be waked up in time.
>

I'm not sure just how tight the timings are. I know when the timings
were too short there were problems but they may be able to be a bit
longer. In past code I've written I've used one of the CIA timers,
set it not to interrupt, and polled for when it timed out. Accurate
but not friendly to the OS! What is the smallest timeout I can do on
the system using the regular OS features and not hogging the system?
1 tick + time before I get notified the tick has gone by?

The timing is all in the track stepping and motor control. Once that
is done a whole track is read in by dma and then there is a disk block
done interrupt.

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+------------------ Brad Pepers -- [email-masked] -------------------+