Hi,

Over a year ago, a friend gave me his somewhat-expanded Amiga 1200 for parts/safe-keeping. I just recently transplanted his FZ-375A HD floppy into my A1200 tower. With no disk in the drive, I can see the light flashing and hear it clicking (very faintly), and if I connect the 34-pin cable upside down, the light stays on and I believe the drive spins continuously. But (with the cable on correctly), when I place any floppy in the drive....nothing.

The cable I'm using is a standard 2-connector Amiga floppy cable, not a PC floppy cable with the twist.

I will be doing more troubleshooting, but wanted to ask if anyone was aware of a simple fix. I thought these drives were supposed to be just connect and go?

Thanks!

Todd

P.S. Been away for a while. Gosh, it feels good to be back!

@thetao

A short update:

1) A different cable made no difference.
2) Booting with no drive at all generates a "DF0:Unreadable" icon.
3) The jumper on the back of the drive is in the lower-right position. Put another way, looking straight-on at the drive rear, the lower-right and center-bottom pins are covered. The "key" on the back of the cover indicates the jumper block should be a 7x2 layout, but it's actually a 6x2. The jumper seems to be in the "DC" position. Is this correct?

One more update:

I meant to say the jumper block on the drive is a 3x2. I tried moving the jumper to the RDY position (upper right and lower right?), which definitely changed things. The drive still isn't seeing disk changes, but the diskchange command works now and the LED shines brighter. But after spinning for a moment, the disk is still not readable, with "DF0:Unreadable" still appearing on Workbench. And I tried many different floppies. Inserting a HD floppy still gives me only a DD option when formatting through Workbench or through the Format program in Sys:System.

Still seems like I'm missing something fundamental...

@thetao

Forgive me for asking, but did it ever work? I seem to remember that a standard PC floppy won't work in a Classic unless you have a special cable with a bit of hacking.

But then, I haven't used a Classic now for many years, so I might be talking cr*p...

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@tonyw

Hehe, but it's not a standard floppy. The Chinon FZ-375A is THE Amiga high density drive. I haven't spoken to my friend in quite a while, but the floppy was one of the highlights of his 1200, and I'm sure at the time that *he* thought it worked fine.

@thetao

AFAIK the floppy was used in Amigas and in PCs depending on the jumper settings.

Maybe this picture can help you (i didn't make it but i found it via google).

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@thetao

Is your A1200 a Commodore or an AmigaTechnologies build?

if its the latter you might need some fiddling and the original HD-Floppy will not work right away.

@thetao

Should I assume the jumpers were working as is prior?

I wonder, if settings DS1 (Drive Select 1?) would help as IIRC a HD drive has to be on a seperate unit to DF0. On the A4000 anyway IIRC.

Also, have you tried adding a twist in the cable, to see if that works better?

@thetao

My A3K came with one of these drives as df0:.

It worked fine for a long time, but as the machine got older, the contacts on the floppy detect switch got dirty and it became unreliable. It's a switch near the front of the drive. It's a pin that gets pushed down when the floppy is inserted. I could actually reach in and trigger it with my finger while the machine was running.

Maybe your drive is having trouble with this switch.

@thetao

It sounds an awful lot like a PC-configured drive, or possibly someone nicked the jumpers off it at some point.

Not sure of the default jumper config for an FZ357A (I no longer own one), but you may need to enable the disk change signal on pin 2 and the 'Ready' signal on pin 34.

See here for further details.

In the meantime (or as a workaround) try "diskchange df#:" at the CLI (as suggested here).

Regards



Rich

PS - Welcome back

Last edited by Boot_WB on 19-Nov-2010 at 03:30 PM.

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Thanks for all the replies!

@cHaOs667

Your picture shows the original FZ-357 drive, not the -A variety for Amiga, but it does have the 7x2 jumper layout, vs. the 3x2 layout on my drive. When I zoom in, I can't quite see enough detail to tell how it's configured, but may have a better look later.

@Hypex
@Boot_WB

I'd been wondering what all the jumpers were for, and so thanks for the tips. Will investigate this more.

@robo-ant

Good suggestion. The first thing I tried today was dismantling the drive and saturating the two microswitches in the front with contact cleaner. I'm not sure how much of it got inside, but I learned long ago that dismantling microswitches usually doesn't work. Unfortunately, no difference. Worst case scenerio, I will desolder and replace them with switches from another drive.

@Amigo1

I bought this motherboard new from Vesalia in Germany in 1999 or 2000, because I wanted to a clean system for OS 3.5/3.9, and new 1200's were scarce in the USA. The board reads

A1200 Revision 2B (the top of the "B" didn't print correctly)
Commodore Electronics Ltd
(c) Copyright 1992 All Rights Reserved

plus a lot of other writing. How do you pick out an AT motherboard? But maybe this answers one small mystery? While doing some housekeeping recently, I found a small Amiga Technologies floppy adapter board that I'd never used and couldn't remember how I got it:



Perhaps it came with the motherboard? Until now I've been using a PC floppy with a Kywalda board. I recall reading yesterday that AT 1200's weren't any different, but the floppy drives required a dongle to operate, because AT wouldn't pay the $$ to commission a special batch. So I'm guessing this board is a sort of "Kywalda lite"? I still think I should be able to connect an FZ-357A directly, even if it is an AT board.


Changing the jumpers around didn't make things any better than my earlier RDY test. Diskchange works, but all disks are still unreadable. Then I ran the drive with the cover removed and realized the read/write head wasn't moving at all! I then shut everything down and very gently removed the 3 ribbon cables that push into the circuit board, and sprayed the connectors with contact cleaner, too. Still no difference. I even ran an old "head cleaner" program that I believe is supposed to step the heads. So I am starting to think the drive really is a dud. Short of finding a magical jumper combination, I guess the best course of action now is to dig out the original 1200 and see if it works properly there.

But if someone has one of these FZ-357A drives in a 1200, I would still love to know how your jumpers are configured. And any other suggestions, too.

Thanks everybody!

Still more testing...

I decided to return to Kywalda + PC floppy so I could observe the movement of the read/write heads. But now the PC floppy is showing the same symptoms! It doesn't recognize when a disk is inserted, and the heads don't move at all. I have barely used this Amiga in the last 3 years, and so don't know what could have happened to the floppy controller (the CIA chip, right?). But I recalled that each CIA chip serves multiple functions. I tested joy1, joy2, keyboard, serial, and parallel, and all this works normally...so now I am nearly stumped. The only thing I haven't tested is the external floppy connector. I still have an enclosure from a third party external floppy that I used with my Amiga 1000, back in the early 90's, and if this is compatible with a modern HD PC floppy, I will test this port sometime. But for now, my best guess is.........a bad solder joint?

Troubleshooting this will take more time than I can currently spare, so I shall have to put if off a little while. But if anybody still has suggestions, particularly about CIA troubleshooting or settings for the FZ-375A's 3x2 jumper block, I'm listening.

@thetao

Yes CIA also controls floppy. At least CIA B is involved. And you are right that CIA has multiple functions.

Perhaps check your floppy cables. Make sure that all the data is getting through. With a multimeter or such.

@thetao

Just a quicky, but how is your amiga powered, is it via the original cream box psu or have u connected a PC supply to it. As i seem to remember if using a PC supply, when the center pin (i think the 5v line) into the Original(5pin) Amiga power port wasnt connected, then the Amiga Audio and i think possible to floppy didnt work.

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@thetao

Sorry, I was wrong. My A3K has a Chinon FB-357A in it. It has the 3x2 jumper block on it, though, so it may be the same as yours. Mine is set for DS0.



Hope this helps.

@robo-ant

Thanks for the pic. That's how my jumper was originally set, so now I know that wasn't the problem.

@TheAMIgaOne

Wow, I just had a flashback to the 9v input line on the C64! :) My 1200 is in an Elbox Power Tower, and using its PC power supply. +5v seems to be okay, as the hard drive, CD R/W, etc. work fine. Sound does too. But these lines are separate from the one going to the motherboard, and as I do have at least once brick power supply, that will be a simple thing to test once I have time to remove the motherboard.

@Hypex

Since everything else is working (have yet to test the external floppy port), I'm assuming this is not actually a CIA problem. My very first 1200 motherboard (bought used around 1995) also had floppy problems. I took it to an Amiga repair shop (wow, how rare is that) and in the end, they just resoldered the connector. I haven't used the Amiga much for the better part of 3-4 years, and don't remember when I used the floppy last, so am hoping the weight of the cable just pulled something a little loose.

Unless someone has more tips on CIA/voltage troubleshooting, I will make time to test everything around Christmas, and will post a followup then. Thanks!!!

@thetao

If at all possible, your next test should be the external floppy connector with a standard Amiga drive. If it works, then your CIA is just fine (hope so!)