[Coco] FD-50X Drive manuals

[Gene Heskett]

On Saturday 07 March 2009, Bill wrote:
>I have 3 separate drives (a FD-500 and (2) FD-502s).
>
>I have 2 controllers (a FD-500 and a FD-502)
>
>I have 2 cables (a flat ribbon cable and a rolled shielded cable)
>
>I only have 1 computer (a 26-3127 Coco2).
>
>Regardless which controller I use, or which cable I use, the result is the
>same.
>
>Two of the three are FD-502. Between them, there is (1) FD-502 controller,
>one flat ribbon cable, and a round shielded cable. The drives act like this
>(regardless of which controller is used, 500 or 502, or which cable is
>used): When the DSKINI0 command is given, the drives "click" through each of
>the 35 tracks slowly, but instead of returning to the beginning and doing it
>again quickly to verify, they just spin a few seconds and display an ?IO
>ERROR
>
>The third is a FD-500 w/controller, but no cable. I've been using the cable
>from the first 502 (a ribbon cable). The drive acts like this (again,
>regardless of which controller is used, 500 or 502): When the DSKINI0
>command is given, the drive "clicks" through 18 of the 35 tracks slowly, but
>then it stays in the same place for 4 more "clicks", and displays an ?IO
>ERROR.
>
>Unfortunately, I don't have any to test anything else.

1. Do the activity leds on the drives come on? (1 at a time)

2. Is this cable a 'twisted' cable (so that both drives can be set to respond 
to disk selector signal ds1, and check the drives for their jumper settings 
for that)  and does it have any missing contacts in the card edge connectors 
that plug onto the backs of the drives?

I am told that the twisted cables used for the coco's are not twisted in the 
same exact manner as those used in now very elderly pc's, you may have a 'pc' 
cable somebody threw in the kit just so it had a cable.

3. It would be unlikely that all 3 drives have worn or dirty heads, but the 
dirty part can be checked if the drive is removed from the box by wetting a q-
tip in the alcohol sold at paint supply stores such as Ace Hdwe.  Rubbing 
alcohol is cut with water and the denaturing additive, but the paint store or 
ace hdwe stuff is the real thing.  The heads can be identified once the drive 
is out of the box, they slide in and out in a position directly behind the 
disks hub driving spindle, and are usually what looks like a white ceramic 
thing about 3/16" square, mounted very flimsily in the end of the arm of the 
carriage.  Slide it to an accessible point, and wipe the face with a q-tip 
wetted with the alcohol, gently of course.  Single sided drives will have a 
felt pad on the other arm that faces the other side of the disk.  Give it time 
to dry is you get it damp.

While you are in there, the drives will probably thank you for a drop of 
sewing machine oil applied to the rods the head carriage slides on.

4. Another ugly thought, are the disk spindles belt driven?  Maybe the belts 
are slipping and the disk itself is not turning at its normal 300 rpm.  Along 
the same lines, the plastic rosette that presses the disk hub to the drive 
spindle may also have relaxed over the years, that reduces the grip pressure, 
so the disk itself, with its liner lubes all evaporated over the years which 
makes the disk hard to turn in its sleeve, and then the hub is slipping.  This 
can usually be identified by putting a magic marker mark on both sides of the 
hub hole, and doing a dskini.  Then look at the mark, if worn away on one 
side, its slipping there.

FWIW, this is a huge problem with 8" floppy drives, been there, done that.

>> -----Original Message-----
>> From: coco-bounces at maltedmedia.com [mailto:coco-
>> bounces at maltedmedia.com] On Behalf Of Joel Ewy
>> Sent: Saturday, March 07, 2009 10:12 PM
>> To: CoCoList for Color Computer Enthusiasts
>> Subject: Re: [Coco] FD-50X Drive manuals
>>
>> If 3 different drives fail in exactly the same way, I might start to
>> suspect a different part of the system, like the cabling (the
>> connectors, the cables themselves, or the orientation in which they're
>> plugged in), the power supply, or the controller.  Do you have a good
>> way to test out those other pieces?
>
>--
>Coco mailing list
>Coco at maltedmedia.com
>http://five.pairlist.net/mailman/listinfo/coco


-- 
Cheers, Gene
"There are four boxes to be used in defense of liberty:
 soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
If you find a solution and become attached to it, the solution may become
your next problem.