Amiga 500 floppy issues

[Gyromite]

I have a Chinon FB-354 drive taken from a enclosure to be converted to an internal. This raised a few questions. All the tech specs say this has 6 pins for jumper settings. I only see three, however the drive seems to be recognized fine with the current settings. The drive will spin on boot and stop regardless of what WB 1.3 or bootable disk I put in. If I take the disk out and put a new one in, it will not try to load again. I've got no idea. Thanks for the help.

How about a video of it? http://www.youtube.com/watch?v=oZa4YECvvQQ

 

[BLTCON0]

Three pins = DS0 & DS1 (PCs only need those)
Six pins = DS0 - DS1 - DS2 - DS3 (FB-354's for Amigas indeed had all these)

So there are good chances it's meant for PCs. Are there any other jumpers hidden somewhere? I THINK there was a version of this drive bare of jumpers but there was an option PCB that plugged onto the drive and provided the missing settings which could make it work in "amiga mode". If I'm not remembering nonsense, you could perhaps have such a unit (the functionality of such a PCB could easily be implemented in the external case's circuitry).

So, if it's setup as a PC drive, the quickest way to make it work is setting it to DS0 and cross-joining wires 2 & 34 of the floppy cable (this is a partial solution, suitable only for Amiga DOS). If for any reason the drive is fixed to DS1, you can make it appear as DS0 by also cross-joining wires 10 & 12 of the floppy cable.

Actually if you have another way of booting (e.g. a hard disk) you don't even need to modify the cable, you just have to issue "diskchange df0:" in a CLI window to force Amiga DOS to detect the disk every time you insert a new one. But you still need to set the drive as DS0.

And make sure the drive actually works! When was it last seen properly working? Give it a good clean especially the heads if it's been unused for a long time (there is info about that on Amibay).
The kind of delay before it returns to the KS screen in your video isn't encouraging.

 

[Gyromite]

Thanks for the reply. This drive originally was an external Amiga drive and worked fine. The original HD in my GVP A530 died so I have to get the floppy drive working at least temporarily in order to reinstall the GVP software. As I'm sure you know, WB 1.3 has no way to load off an external on bootup so my only option was to strip it out of the case and get it setup as an internal.

Also, yes there was a jumper on pins 2 and 3. This would only cause the power light to come on. I moved it over to 1 and 2 and got the result on the video.

You may be on to something saying it may be "hard wired" for DS1. I'll look into cross joining, but I may just invest another $25 and get a drive that will work out of the box. Thanks again...

 

[BLTCON0]

Thanks for the reply. This drive originally was an external Amiga drive and worked fine.

Ok so it's functional.
But that doesn't mean it's a direct replacement for an internal drive either.
I have a Datalux SV-702 external Amiga drive which uses an Epson SMD-400, which is incompatible to both the Amiga and even standard PC pinouts. With the suitable interface PCB it works, of course.

The original HD in my GVP A530 died so I have to get the floppy drive working at least temporarily in order to reinstall the GVP software. As I'm sure you know, WB 1.3 has no way to load off an external on bootup so my only option was to strip it out of the case and get it setup as an internal.

It's KS 1.3 that can't boot DF1: , WB 1.3 will boot fine off an external drive if you have a higher Kickstart in place.

Also, yes there was a jumper on pins 2 and 3. This would only cause the power light to come on. I moved it over to 1 and 2 and got the result on the video.

What are the jumper designations? I can only guess they're for DS0 and DS1 setting, but you must verify this.

You may be on to something saying it may be "hard wired" for DS1. I'll look into cross joining, but I may just invest another $25 and get a drive that will work out of the box. Thanks again...

If you're sure it's fixed to DS1, reversing wires 10 & 12 will make it DS0.
By the way, you're using the standard Amiga floppy cable which has no twists like PC ones, right? The 10-12 swap wire trick is meant for a standard untwisted cable.

Your video isn't very revealing, but does the drive sound like making three attempts to read the disk before it gets back to the KS 1.3 screen?

 

[Gyromite]

It's KS 1.3 that can't boot DF1: , WB 1.3 will boot fine off an external drive if you have a higher Kickstart in place.

Right. That's what I meant to say.

What are the jumper designations? I can only guess they're for DS0 and DS1 setting, but you must verify this.

The 3 pins show DS0 and DS1. The board itself has DS2 and DS3 on the back but have no soldering points showing jumper pins were there. I'll take a picture to show later on this evening.

If you're sure it's fixed to DS1, reversing wires 10 & 12 will make it DS0.
By the way, you're using the standard Amiga floppy cable which has no twists like PC ones, right? The 10-12 swap wire trick is meant for a standard untwisted cable.

I'm not sure of anything! Yes, the floppy cable is the original one that worked with the previous internal floppy.

Your video isn't very revealing, but does the drive sound like making three attempts to read the disk before it gets back to the KS 1.3 screen?

I agree about the video. It was quick as I incorrectly thought it would be a quick fix. The disk only spins. I do not hear it trying to read any sectors on the disk.

Thanks again
Gyro

 

[BLTCON0]

Ok so the DS0 setting should work fine Set it so.
Now let's say it's a PC drive. The PCB would be identical to the Amiga version though, just differently configured. What rev is your drive?

Also try this: Place the WB 1.3 disk into the drive BEFORE power up, then power up. Try this with both your normal cable AND a cable with wires 2 & 34 cut (you can use the untwisted part of a PC floppy cable for testing).

 

[Gyromite]

I got some pictures that hopefully may help... and a new situation. I will try your cable tests tomorrow.

-------------------

I took out all the cables and reinstalled, and now the power light stays on all the time. If I put a disk in, it spins forever now. If I take it out, the spinning stops. Here's some new pics to make sure my cabling is right. The white stuff on top was tape to hold it in the external case.

 

[johnim]

the cable on the floppy is on back to front turn it over, also make sure none of that gunk is in the drive

is the disk really bootable it may be currupt?

 

[BLTCON0]

@Gyromite
Check the cable ends orientation, as johnim said it's plugged the wrong way on the floppy connector (pin1 = on the left side = where the red stripe should go).
At the same time make sure the red stripe is on pin1 of the motherboard connector too, of course. Pin1 is closest to the floppy drive and away from the floppy power connector.
(if you have reverse-plugged both ends as it looks like from the photos it should be ok, but it's still best to stick to the established conventions).

You can check if it's an Amiga-ready drive: take the drive apart and spot the 74LS06 IC on the non-visible side of the board. Do a continuity test. Pins 2 & 34 on the header should connect to pins 8 & 12 on the 74LS06 respectively.

Also test the motor without the flat cable attached (just power). Power on and press the "disk inserted" detection switch (it's the righmost of the two switches visible on the left side of the front opening). Keep it pressed. The motor should spin up for 1-2 seconds and then spin down, even though you are still pressing the switch. If not, there's a problem with the drive itself.

 

[Gyromite]

the cable on the floppy is on back to front turn it over, also make sure none of that gunk is in the drive

Thanks. I swapped both sides over. Double checked the drive and it looks clean inside but I cleaned the drive heads to be sure.

is the disk really bootable it may be currupt?

It's possible.The GVP A530 disks are bootable and I don't have a copy of those. It would be great if someone out there can grab the install disks, test them, and send them my way. My GVP I bought did not come with them anyway. The link to them is here.. http://www.gvp-m.com/a530.dms

(if you have reverse-plugged both ends as it looks like from the photos it should be ok, but it's still best to stick to the established conventions).

Both ends were reverse plugged as you said, and you are correct about the result. I got the same results of the drive spinning constantly on power up.

You can check if it's an Amiga-ready drive: take the drive apart and spot the 74LS06 IC on the non-visible side of the board. Do a continuity test. Pins 2 & 34 on the header should connect to pins 8 & 12 on the 74LS06 respectively.

That would be a great test but I don't have the equipment to do that. Besides, knowing me, I'd short the thing. Rev A is listed as an Amiga compatible drive in the drive compatibility list.

Also test the motor without the flat cable attached (just power). Power on and press the "disk inserted" detection switch .

What a great test that is! Yes, the drive spun up just fine when I pressed that pin down and stopped as you said. At least now I know I haven't destroyed the thing from my hours of playing with it.

In summary, what basically happens now is the drive constantly spins with a disk in on power up with no track seek sounds and quits spinning when I take the disk out. You wouldn't think something that sounds so simple could be so much trouble. Thanks again in investing your time to help. If anyone can send those GVP disks, PM me and I'll send my address.

 

[BLTCON0]

Ok to be honest the PCB on my "Amiga" revA FB-354 doesn't seem to have any jumpers related to where the DISKCHANGE and READY signals would go, and I doubt they'd make a different revA PCB for a "PC" FB-354. Seems the only thing they did is omit the DS2 & DS3 jumpers. So let's assume it's an "Amiga" drive indeed.

Do the same test (with no flat cable connected) but now insert a disk instead of manually pressing the switch. This should not make any difference: the motor should spinup and then spindown just like before. If it keeps spinning, again it's a problem with the drive.

 

[Gyromite]

It spun. It made two complete revolutions when I put a disk in.

 

[BLTCON0]

Well, of course it would spin, when the disk is fully inserted it gets lowered and depresses the detection switch much like you manually did. The question was whether it would spin down.

Ok so it did spin down.

So you might be looking at interface problems or bad disks, I suppose the GVP and WB 1.3 disk is all you have or you'd have already reported failure with other disks too.

You have disconnected the GVP accelerator of course, eh? All this testing should be done with the absolute minimum in hardware.

At this point, you definitely need a set of known good bootable disks.
You also need a definitely known good cable.

All I can suggest then is to grab a definitely known good PC floppy drive, and connect it to the Amiga with the modified cable I suggested before (wires 2 & 34 swapped, wires 10 & 12 swapped).

If the symptoms continue, you might be looking into a problematic CIA chip.

You can actually already test this - swap the two CIA chips and see if the behaviour changes. Hopefully at least one of the two is good so it'll give you a clue if that's the case. Careful with removing/inserting the chips from/into the sockets, also with their orientation.

 

[Gyromite]

Yes, as far as bootable, the WB 1.3 disk is all I have. I also have a copied GVP disk and it does the same. I have no idea if the disks are good or not as I bought the whole lot as is.

GVP has been disconnected the whole time.

I had an Epson disk drive on there before that had apparently spilled coke on it. What that drive did was give three loud disk seek sounds before erroring out. I tryed my best to clean it but it didn't make a difference. This particular drive only had power and ground pins so I had to replace it with this four pin power cable when I swapped the drive.

I have some old BBS friends that may still have their Amiga and might be able to get some disks from them. I'll start that route first and report what happens. Thanks again for your time!

---------- Post added at 20:33 ---------- Previous post was at 18:36 ----------

After examining the drive one more time, I think I may have noticed something. Are those two black squares you see on this picture supposed to have anything attached to them? It almost looks as if something broke off..

 

[BLTCON0]

No, that's just fine, they're just joints for two rods that run into the drive.