[Coco] Rusty ole FD-501

[Chad H]

What I mean is that I saw on some web links that certain controllers wouldn’t work with high density drives.
Like here.... http://tinyurl.com/kzog62g

It seems to suggest that controllers with the WD1773 chip were not capable of supporting it.  I don't know what that means!
Does I it mean you can't use the HD 3.5" drives at all?  Does it only mean you are stuck with low density functionality?
All I know is my FD-502 controller with HDBDOS EPROM seems to be handling it just fine.  But like I said, I haven't tinkered with NitrOS9 using the drive yet.

-----Original Message-----
From: Coco [mailto:coco-bounces at maltedmedia.com] On Behalf Of univax!gatech!destroyer!trantor!kandur
Sent: Tuesday, January 13, 2015 7:50 PM
To: CoCoList for Color Computer Enthusiasts
Subject: Re: [Coco] Rusty ole FD-501

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

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