On Tue, 15 Feb 2005 shoppa_classiccmp_at_trailing-edge.com wrote:
> Sounds like you weren't getting the "drive ready" signal from drive 0.
> Maybe it was a problem on the 50-pin floppy bus messing everything up
> for a while.
>
> On generic 8" floppy drives (e.g. Shugart SA801), "drive ready" comes
> from a one-shot triggered by the LED/photodetector that shines through
> the index hole. Ambient light can mess up thresholds, leading to
> some bizarre circumstances like "it works with the cover on but not with
> the cover off", "it works with the cover off but not with the cover on",
> "it works fine until 4PM in the afternoon" (which happens to be when
> the sun shites through the window into the drive box, etc.)
Hmm, I keep the cover on during normal operation and I'm in a room with no
outside light (have windows covered to prevent morning sun from heating up
the place early in the day during summer months).
> Mechanical alignment of the index LED/detector can be a little out of
> whack sometimes. There's also a pot on the PCB for setting sensitivity,
> IIRC.
I checked on that but the sensor is mounted pretty firmly. I didn't spend
very much time on it (just cursory glances) but maybe I'll look at it a
bit closer the next time I pop the cover.
--
Sellam Ismail Vintage Computer Festival
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Received on Tue Feb 15 2005 - 17:17:25 GMT