[Coco] Rusty ole FD-501

[Chad H]

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