[Coco] Rusty ole FD-501

[univax!gatech!destroyer!trantor!kandur]

Chad, 
you mention "high density drives" several times.
What do you mean exactly by that?
I made a second descriptor for a DS DD 720k 5.25" drive,
(with help from Gene Heskett and Bill Price) 
that matches a 3.5" 720k drive. If interested, look around here, 
http://qdv.pw/coco/?s=descriptor 

Kandur

Tuesday, January 13, 2015, 5:04:06 PM, you wrote:
> OK, so I received the FD-501 drive enclosure from eBay with rust on the outer
> shell but when I opened it, it was in surprisingly very good and clean
> condition.  I fired it up, rand a cleaning disk through it and performed
> several DSKINI, BACKUP and other operations to confirm it was working..and it
> was.  It was very quiet and smooth, too bad its a single sided drive though. 
> I was looking to use this enclosure to add the ability to work with 3.5" dusks
> so I pulled the 501 driver, bubble wrapped it and stored it.  I soldered in a
> 3rd power harness to the power PCB for 3.5 inch type plug and swapped the
> ribbon cable with a old round 502 drive cable 8 had attached a 3.5" IDC
> connector to.  I have a box full of brand new 3.5" 1.44mb floppies and decided
> to give it a try even though the only controller packs I had available are
> 502's.  I let the 3.5" drive be #1 unit since they are jumper less and
> installed a spare 360k 5.25x drive jumpered for #0 unit.  I have virtually no
> 720k diskettes anymore so tried a few NIB Imation 1.44mb diskettes with
> consistent results. I read somewhere you need a older controller pack for high
> density drives. apparently this is not necessarily true.  I also thought I saw
> a post saying the HD / DD density hole on the 3.5" disks have no effect in the
> CoCo... Also not true, though i'm not sure what its changing since the
> OS9-BOOT speed test tool reported approximately 300rpm whether it was taped over the notch or not.

> The whole thing was plug-n-play for me except for one thing..that density
> notch.  With it covered, my CoCo would read/write flawlessly fast and smooth
> to its own formatted disks and those done on my PC using the DSKINI.EXE
> utility.   There was a strangle glitch with the utility though, I think I've
> seen it before with the 5.25" drives, where it wouldn't RETRIEVE side 2 of a
> disk written by the CoCo until you need did this weird thing...
> 1) eject disk
> 2) DIR -enter-  (drive noises and DOS errors of course)
> 3) reinsert disk and RETRIEVE then it does fine

> Again this only effected side 2 reading...strange.  I haven't yet tried with
> other disk utilities for comparison.  So far no real problems with the 1.44mb
> drives/media in HDBDOS.  I haven't loaded up NitrOS9 yet but imagine it will
> act like a 360k drive there too.  Maybe the whole high density issue was with
> trying to get extra capacity under NitrOS9?  I don't know.

> If anyone could shed some light on any of these issues or concerns please do
> so.  Also, if you have further "tests" I could try to make sure this setup is
> working as reliably as it seems, that would be great too.  I still have a
> bunch of the same model drive used for spares if I need to get any information
> or pictures.  And thanks to those other hybrid floppy users that gave me itch to go ahead and do this!

> Sent from my Transformer Infinity