[Coco] Help with my CoCo FDD

Mon Nov 19 21:21:40 EST 2018

On Monday 19 November 2018 19:35:10 Walter Zambotti wrote:

> Thanks
>
> The access led always seems to be on at all times!

Thats usually a good sign its plugged in upside down, effectively 
interchanging the signals and grounds. Doesn't usually do any damage, 
but could.

>
> One of my cables has a double end like you describe. The other is just
> single ended. Neither are tandy factory, just some 3rd party so I'm
> not sure if either is equivalent to the factory cable.
>
So they are both fully wired cables. which means you need to jumper the 
drive addresses as 0 and 1.

Are there any "dividers" in the cable plugs to keep you from plugging 
them in backwards? In non-factory stuff thats often left out, allowing 
the cable to be plugged into the controller or the drive, upside down. 
That divider/blocking thing is close to the pin 1 end of the connector, 
so locate the connectors pin one, often marked by a triangle and place 
the cable so pin one is near the slot in the pcb tongue of the drive 
that the divider, if present slides into.  On both ends of the cable. If 
the access led is still on, then you've likely blown a 7404 in the 
controller, it does happen very occasionally.

> My Tandy drive and controller came with the factory cable but I need
> to get that out of storage.
>
> I don't know if my setup is common but I know that I was able to
> access both sides of the floppy from disk basic by using drive(0/1)
> without changing jumpers.
>
> OS9 could access both sides as a single floppy.
>
> What I didn't try was jumper D1. I assumed D0 or none.

With cables with the twist, both drives are D1
>
> At the moment the only jumper setting that seems to get close to
> working is a single jumper in MX. Then dskini(0/1) begins working.
>
> I will reclamp the cables as I didn't consider this! Thanks.
>
> The edge connectors are clean.  A little gentle use of some steel
> wool.

Which is conductive, give it a good blowout with an air hose.  Thats why 
I said paper, as in newsprint, it has just the right abrasive effect, 
and is not conductive (unless soaked in salt water)
>
> Walter
>
> -----Original Message-----
> From: Coco [mailto:coco-bounces at maltedmedia.com] On Behalf Of Gene
> Heskett Sent: Monday, 19 November 2018 4:35 PM
> To: coco at maltedmedia.com
> Subject: Re: [Coco] Help with my CoCo FDD
>
> On Monday 19 November 2018 01:21:36 Walter Zambotti wrote:
> > >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.
> >
> > Thanks Gene
> >
> > I should have said I have backed off from trying to get both drives
> > working together and all my testing was just with 1 drive at a time.
> >
> > So if I only have 1 drive connected then I should just need a jumper
> > on 0 & Term!
> >
> > However one of the drives only spins up when I jumper MX even when
> > it's the only drive!  I'll check the edge connector.
>
> With the factory cable, the end connector is drive 0, but it needs a
> jumper set for drive 1. The twisted part of the cable makes it drive
> 0. the drive set as drive 1 is then the middle connector and will be
> drive 1. Stuff is numbered in base 0. Make that drive work by itsself
> on the end of the cable, and verify that a dir(1) doesn't light its
> access led, but does run the motor. You might have to use some contact
> cleaner and some newspaper to clean the card edge patterns on the
> drives, clean until the newspaper stays clean if you get some fresh
> paper, wet with cleaner and go back again, pinching the paper against
> both sides of the contact, particularly if it looks to be solder
> plated. If gold, its not very thick so be more gentle. At the cables
> age, if you can see a space in the cable to connector joint, don't be
> afraid to stick it in a vice and clamp it tight again. Its now 30+
> years old and a lot can happen to an insulation displacement connector
> with that sort of age on it.  Where the internal fingers punch thru
> the wires  as they are pressed into the slit in the contact pinching
> and connecting to the wire was never what we'd call a gas tight joint
> to start with. So oxygen from the air we breath does get in to oxidize
> things. You may find its bad even after the trip to the vice, so don't
> be surprised if you have to order up enough of those connectors and
> some 34 conductor cable to make a newer one.
>
> I've had to do it 2 or 3 times now with the db25's used to drive my
> shop cnc machinery at less than 10 years. Thats a much dirtier
> environment though. Cutting oils and "swarf", aka the metal cuttings,
> can get into the darnedest places. Biggest problem is the keyboards,
> so a lot of this stuff does have a mouse or keyboard, but a touch
> screen. But BIG touch screens cost too much, so I've resigned my self
> to losing at least a keyboard a year somewhere in the shop.
>
> > I'm going to get my Tandy ctrl and drive out of storage and test
> > that.
> >
> > That should at least prove the CoCo is not the problem.
> >
> > Walter
>
> Good idea.
>
> > > -----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>
> >
> > --
> > 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>
>
> --
> 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>