[Coco] Help with my CoCo FDD

[Gene Heskett]

On Sunday 18 November 2018 22:44:01 Walter Zambotti wrote:

> Ok guys.
>
> I have two CoCo III a CoCo I and three FD setups.
>
> FD1 Is a Real Tandy Controller and FDD. I haven’t used this in a while
> but I think it is working.
>
> FD2 Is a Shinon FD502 slim case with a third party controller that
> supports 42 tracks. Used on my main CoCo III.
>
> FD3 Is a Shinon FD502  full height case with an ugly hacked
> controller.  This was used on the CoCo I
>
> Neither of the shinon FDs with either controller are working at the
> moment!
>
> At the time I messed things up I was trying to get both shinon drives
> into the full height case.
>
> Anyway both controllers can see both shinon drives ad I can do a
> DSKINI0 and they both start working but after formatting 35 tracks I
> get an I/O error. So they spin up and heads move around but not
> reading any data.
>
> It could be that the media is all 30 years old but I had some unused
> Tandy certified floppies that have also failed.
>
> Then jumpers on the FD502 are pretty straight forward.
>
>
> 0 1 2 3 MX Term
>
> I checked the jumpers on the other shinon drive which are set the same
> just one jumper on 0.
>
> I managed to determine that there was only 0.5 volts on the 5 volt
> rail which was due to a loose contact which is Now sorted but it's
> still not working.
>
> I think MX is for cable select or Always selected.  I found no clear
> documentation on this.
>
> Link to images here;
>
> https://1drv.ms/f/s!AgghqTS6bkpArCAjVbeIx1zmaOiU
>
> It's the smaller controller FD2 that I want working.
>
> I have also tried swapping cables in case that was issue.
>
> Walter

This has the quack and waddle of two ducks, both wanting to be first, 
drive 0.  From prior experience the first thing I'd do is look into the 
edge connector pulled off either or both drives. Missing teeth? then 
both drives need a jumper on 0 (1) 2 3 MX Term
                             0 (1) 2 3 MX Term because the twist in the 
cable makes the 2nd & last drive into drive 0, and in any event you'll 
need a jumper on Term for last drive on the end of cable.

If someone has replaced the connectors with ones with all their contacts 
and no twist in part of the cable, then the 1st drive needs a jumper on 
0 and the 2nd drive needs a jumper on 1, and that last drive also needs 
one on Term. This is how I've had mine setup since I got my first coco.

MX generally is a switch that tells the drive to start the motor when 
motor on is active regardless of the drive select lines. CoCo 
controllers do not have a motor up to speed pause when switching drives 
so set a jumper on both MX's if only the drive selected runs its motor. 
Both should run purely from the controllers motor on signal so all drive 
spin at the same time.

Good luck. If the drives are otherwise good, you should be doing the 
happy dance.


> -----Original Message-----
> From: Coco [mailto:coco-bounces at maltedmedia.com] On Behalf Of Gene
> Heskett Sent: Tuesday, 13 November 2018 1:11 PM
> To: coco at maltedmedia.com
> Subject: Re: [Coco] Help with my CoCo FDD
>
> On Monday 12 November 2018 23:32:03 Walter Zambotti wrote:
> > Hi guys
> >
> >
> >
> > Advance help request.
> >
> >
> >
> > I was cleaning up my FDD and a jumper fell out (from I don't know
> > where!) And there are numerous jumpers on the FDD and I don't know
> > where to put it back.
> >
> >
> >
> > After that I can't read any of my FDs!
> >
> >
> >
> > I'm going to take a few pics of the thing and post them online in
> > the hope one of you guys might be able to help!
> >
> >
> >
> > Walter
>
> Panasonic did at one time have that stuff on the web as .pdf's. But
> that was 20 years back too. I have an earlier factory manual on the
> JU-455, but its not that new so the pcb is probably different. But set
> that one on your scanner glass, and send me a PM as a  multimegabyte
> jpeg, with the scanner running at at least 600 dpi, so I can compare
> it with what I have. Send it to me, not the list as it will be huge.
>
> --
> Cheers, Gene Heskett
> --
> "There are four boxes to be used in defense of liberty:
>  soap, ballot, jury, and ammo. Please use in that order."
> -Ed Howdershelt (Author)
> Genes Web page <http://geneslinuxbox.net:6309/gene>
>
> --
> Coco mailing list
> Coco at maltedmedia.com
> https://pairlist5.pair.net/mailman/listinfo/coco



-- 
Cheers, Gene Heskett
--
"There are four boxes to be used in defense of liberty:
 soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
Genes Web page <http://geneslinuxbox.net:6309/gene>