[Coco] floppy controller update

Stephen Castello zootzoot at cfl.rr.com
Sun Jul 6 18:14:10 EDT 2008


On Sun, 06 Jul 2008 17:59:10 -0400, Chuck Youse
<cyouse at serialtechnologies.com> had a flock of green cheek conures
squawk out:

>On Sun, 2008-07-06 at 16:13 -0400, Chuck Youse wrote:
>
>> The only serious problem at this point is what can only be termed
>> abysmal performance.  During the boot process, I'm only getting slightly
>> more than 1Kb/s (essentially 4-5 sectors/second) on the reads.  I've
>> tracked it down to the period of time between when I issue the read to
>> the controller and the time it exits non-DMA mode (once the transfer is
>> complete).  Ideas:
>
>The more I think about this, the more I think it must be an interleaving
>issue.  Consider that the sectors are most likely laid out in order by
>Linux's fdformat.  Consider that I appear to be getting something in the
>neighborhood of one sector every 200-250ms, and then consider that at
>300RPMs, one revolution takes about 200ms.  Bingo.
>
>Does that seem right?  Is anyone even listening to my jabbering
>anymore? ;)
>

It does sound like the interleave is set wrong.  Back when hard drives
big as a Kiev 6c, there were many programs to redo the interleave to
speed up the access.

Stephen
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