[Coco] Help with my CoCo FDD

coco at jechar.ca coco at jechar.ca
Thu Nov 22 08:19:15 EST 2018 

  I had a 5 1/4" floppy drive I had given up on then I tried spraying 
"Deoxit Fader Spray"
  on the contacts that worked like a charm.

On 2018-11-21 05:11, Gene Heskett wrote:
> On Wednesday 21 November 2018 01:08:24 Walter Zambotti wrote:
> 
>> Thanks guys.
>> 
>> I have tried the cable both ways now and I definitely had it the
>> correct way.
>> 
>> Plugging it in the other way causes the led to light and the motor to
>> spin even with the controller is disconnected from the CoCo.
>> 
>> I re-clamped both cables but no difference.
>> 
>> Re-cleaned all contacts with newspaper and blew out all the
>> connectors.
>> 
>> Jumpers settings tried:
>> 
>> None - nothing starts
>  (correct)
>> D0 - only dskini0 starts
> ( which is wrong, mx missing)
>> D1 - only dskini1 starts
> (ditto)
>> D0 & D1 - both dskini0 & dskini1 start
> (wrong, both drives will attempt to put read data on the data line)
>> MX both start
> (runs motors, but without a Dn, no data to data line)
>> D0 + MX : both start
> (correct, only one drive, D0, will rx/tx data)
>> D1 + MX : both start
> (also correct, but data will rx/tx from D1)
> 
>> All the above combinations + Term : No change to above
>> 
>> When I say start the motor comes on and the head returns to zero and
>> then performs 34 steps and then returns to zero before getting an I/O
>> err.
> 
> (classic case of dirty/worn out head. assuming the command was a
> dskini0/1)
>> 
>> Also driveX + dir causes the FD to seek forwards and backwards 3 or 4
>> times before failing.
> again, dirty head/worn out heads/bad disk)
>> 
>> So I thinks it's formatting but fails when trying to read.
> Paint store alcohol, wet long q-tip, Sherwood from drug store, gently
> head heads. Give time to dry before re-inserting disk, minute or so or
> use a clean dry q-tip.
> 
> If clamping rossette is collapsed from old age, maybe the disk itself 
> is
> not spinning in the case of a 5.25 disk, but 3.5's are keyed and will
> spin anyway if motor turns.
> 
>> I'm stumped!
>> 
>> I have determined that one of the chinon drives is faulty as the
>> stepping motor refuses to move the head towards track 0.
> 
> The rods the head carriage slides on need cleaned and re-oiled, light 
> but
> non-drying oil, 3-n-1 or sewing machine, possibly the driveing screw is
> caked full of hardened 30 year old grease, clean until the screws 
> spiral
> groove is shiny clear to the bottom of the groove and relube, chassis
> grease suggested, or vaseline maybe. Check the wire that is the groove
> follower for noticeable wear. I've seen then worn plumb off in Amiga's.
> 
>> Short of scoping pins for signal output I'm not sure what to do.
> 
> Thats the next step after the clean and lube. And it sounds like the 
> data
> pin is what you need to scope. For a dskini you should see data from 
> the
> controller while its stepping in, and when it steps back out to do the
> verify phase, you should see data from the drive, and it sounds as if
> the drive isn't returning usable data if that where you are getting the
> io error.
> 
> There is also a possibility the controllers 1773 is blown. At the tv
> station, with a 255 foot pyrod tower for a lightning rod 30 feet out 
> the
> back door with a 4" wide copper ground strap interconnecting the tower
> to house ground, our stuff took a beating when mother nature got upset
> because somebody called that stuff butter. And the coco's do not have
> grounded power cords. I lost 1773's in the smaller, later controllers
> several times. That chip is IIRC an NMOS tech chip, and they can grow a
> purple plague that kills them just from old age and average humidity
> alone. In that case, see if you can find a Fujitsu MB-8877 as its a 
> CMOS
> tech chip and not subject to that particular failure. And I think its a
> drop in for a WD-1793 in the 40 pin pkg. All are going to be very old
> stock and hard to find.  Check the graveyard electronics site as a last
> resort.
>> Can anyone recommend a replacement FD and controller! It needs to
>> support 42 tracks!!!
> 
> Ouch.
>> 
>> Walter
>> 
>> -----Original Message-----
>> From: Coco [mailto:coco-bounces at maltedmedia.com] On Behalf Of EDDY
>> SZCZERBINSKI Sent: Wednesday, 21 November 2018 7:06 AM
>> To: CoCoList for Color Computer Enthusiasts <coco at maltedmedia.com>
>> Subject: Re: [Coco] Help with my CoCo FDD
>> 
>> I may be wrong in some instances but usually, cable goes "down" when
>> connected. I always try that first when I don't know the direction and
>> it always worked so far with lots of equipments. Hope it helps
>> Eddy
>> 
>> ________________________________
>> De : Coco <coco-bounces at maltedmedia.com> de la part de Walter Zambotti
>> <zambotti at iinet.net.au> Envoyé : mardi 20 novembre 2018 01:46 À :
>> 'CoCoList for Color Computer Enthusiasts' Objet : Re: [Coco] Help with
>> my CoCo FDD
>> 
>> >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.
>> 
>> No dividers but they are clearly numbered 1-2 to 33-34
>> 
>> The number 1 is also adjacent the red wire on the ribbon cable.
>> 
>> I have been placing pin 1 on cable to pin 1 on FD connector (this is
>> the pin close to the connector divider/groove)
>> 
>> However the connector on the controller is not so clearly labelled.
>> There is a "1" printed on the board very close to one end of the
>> connector.  Could mean something else!!!
>> 
>> I will try flipping the connector and blowing out the connector.
>> 
>> I have to get home first!
>> 
>> Walter
>> 
>> 
>> 
>> -----Original Message-----
>> From: Coco [mailto:coco-bounces at maltedmedia.com] On Behalf Of Gene
>> Heskett Sent: Tuesday, 20 November 2018 10:22 AM
>> To: coco at maltedmedia.com
>> Subject: Re: [Coco] Help with my CoCo FDD
>> 
>> 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>
>> 
>> --
>> Coco mailing list
>> Coco at maltedmedia.com
>> https://pairlist5.pair.net/mailman/listinfo/coco
>> 
>> 
>> --
>> Coco mailing list
>> Coco at maltedmedia.com
>> https://pairlist5.pair.net/mailman/listinfo/coco
>> 
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>> 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>

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