[Coco] drive motors

[Robert Hermanek]

Ah, well here you touch on another topic that I've had trouble with:  I 
try on and off, but have never successfully connected any 3.5" device to 
my system.  The situation is...

Coco3, standard disk controller.  Using original ribbon cable that came 
with 5.25 drive, so all connections are card-edge style, and there are 
two connectors available for drives.  I picked up a second 5.25 drive at 
some point, hooked everything up, and have confirmed that with 2 5.25" 
drives, drive 0 and drive 1 respond normally, work perfectly.  So all 
controllers/cable are A-OK.

Next step:  I've been led to believe that pretty much any 3.5" drive 
will work... so I ordered a very clever little adapter that is female 
34-PIN IDC style connector one one side, and nice shiny gold card-edge 
male on the other.  So this give me a 5.25" style connector for any 3.5" 
drive.  I've been careful to double check PIN 1, making sure I don't get 
anything backwards.  I set all this up as drive 0.  At this point I can 
power up, and confirm that remaining 5.25" drive (drive 1) works 
perfectly still.

So:  controller to stock cable to card-edge adapter to 3.5" drive is the 
full connection for drive 0.  Drive 0 appears to respond normally, 
meaning drive select is correct, when I do a DIR0 the 3.5" drive lights 
up and heads move around.  I get an IO error of course, no formatted disks.

I've tried both new HD disks, as well as a factory sealed set of DD 
disks that I picked up, and have this result every time:  Try DSKINI and 
I get an IO error half way through.

Clarification on DSKINI:  What does it do exactly?  As anyone knows that 
listens to their drives, DSKINI sounds like it runs the heads down to 
one end, then slowly ticks through the tracks.  Then their appears to be 
a "stage two" where it again repositions the heads, and runs through the 
tracks more quickly.  Then the process is complete.  If we call this 
stages one and two, then I can say that my DSKINI operation always fails 
after stage 1 -- the heads position, all tracks are slowly advanced 
through, the heads position again, IO error.

Then I gave up for a  while.  More recently, I took a floppy emulator 
that I could not resist buying, and configured that in the exact same 
fashion as the 3.5" drive, and had the exact same result -- it appears 
DSKINI succeeds for some amount of time, then fails part way through.

I'll attempt a link to the emulator:

http://www.amazon.com/Updated-Version-SFR1M44-U100K-Floppy-Emulator/dp/B00C4PCK9S/ref=sr_1_1?ie=UTF8&qid=1373726291&sr=8-1&keywords=SFR1M44-U100K

I've tried both HD and DD media.  I've tried both 1.44 and 720k images 
on my emulator.  I've tried three different physical 3.5" drives -- one 
brand spanking new, the other two from the oldest PC systems I could 
find.  Always have the same experience.

...but I hear others simply hook up 3.5" drives and away they go. Thoughts?

Thanks,
-RobertH


On 7/12/2013 7:20 PM, Robert Gault wrote:
>
> Maybe it is the controller or the way you set jumpers and resistor 
> blocks in your drives. On my two floppy system, the only floppy that 
> turns on is the one in use.
>
> I have tested this with a Disto SC-II and two Tandy controllers using 
> the stock DOS1.1. One floppy is a 3.5" the other a 5.25" drive.
>
>