Strange problem with 1040 ST disk drive

[JP977]

Hello everyone,

 

I have a strange problem with an Atari 1040 ST's floppy drive. When I insert a floppy in the drive, it tries to read the contents of the disk as the drive light turns on and I can hear the typical floppy drive ‘noises’ but every disk appears as unreadable (sometimes the files appear with gibberish names and are unreadable). I tried with many different disks, even some original ones that I’m 100% sure are not faulty but still nothing.

 

I thought it was a floppy drive problem so I replaced it with a new one but I get exactly the same behavior.

 

I opened the case and the ribbon cable looks fine. Does anyone know where the problem could be?

 

Thank you!

[Zogging Hell]

Are these game disks? Often these are copy protected so the contents will show as garbage if you try and read them from the desktop - they require autobooting, so insert the disk immediately after switching on (might be telling you how to suck eggs here so apologies if so ).

 

If not I would ask if you have you recapped your PSU? It could be a PSU power issue, as the floppy will often show faults in that case. The other possible issue is one of your disks is seriously covered in gunk, and that having tried it in both drives you have got some of it on the drive heads. I would pull back the metal cover on any floppy you buy these days and check the disk for obvious crud - you may need to clean the drive head if so, the disks can also gently be cleaned with distilled water and a q-tip. If you have another computer with a floppy drive I would take a disk you don't care about, format it on the other machine to ascertain it is good, then try and format it on the ST. If you can format it double sided with no errors then the disk is likely to be good, and the drive.

[JP977]

Hello and thank you for the answer!

 

Sadly the system doesn't auto-boot either as I already tried it with different disks. I forgot to mention that I also tried to format several brand new disks just out of their orignal boxes but they all show as unreadable.

 

Your question about the PSU made me think as I got the computer on E-Bay and I couldn't know if anyone had tampered with it. I opened the case and I discovered that there are several modifications on the PCB. I attached the pictures to the post. Do you think this could be the reason?

 

 

[snarkdluG]

That's normal. Atari did this. It's factory bodge jobs.

[JP977]

Small update on this topic. I followed exxos' guide on recapping the PSU and I even got the PSU checked by a professional afterwards but the problem is still there: the floppy drive led lights up, it tries to read the disks and after a while it returns a general error message. This happens both with the original drive and a replacement one I got off Ebay.

 

Any suggestion on what to try next? Could it be the motherboard caps or maybe floppy control chips?

 

Thank you!

[Zogging Hell]

Did you try and clean the drive heads? Sometimes they can get crap on that is hard to shift (it only takes one rogue disk to cause a drive to appear unuseable). I would do that first, then other basics like reseating the socketed chips. Check the solder points on the floppy cable, they could have gone dry or been damaged by tugging to get that floppy drive out.

 

It might be an idea to sort a cheap floppy emulator (like a Gotek) off Ebay (or shop of choice) and see if you can read a disk image that way, as then you could at least rule out a disk drive fault (they are all getting tempermental in this day and age).

 

After that a motherboard recap would be a good preventative measure anyway at this stage. The WD 1772 chip controls the floppy, so you could try and change that if your skills are up to it.

[bfollowell]

Hopefully, not your issue, and I'd definitely check all the low hanging fruit first, like pulling and re-seating chips and all that, but it could be the floppy controller chip. Looking at your mobo revision number, that's a 1040STE, not a 1040ST, correct? Did STEs have the AJAX chip, or did they still have the WD1772? Either way, it could be the floppy controller chip, whichever your machine has. Do you have a Gotek drive? If you do, that would be a good way to narrow down the problem to the board or the drive. You've swapped drives, but without another machine to put those drives in to verify they're good, you may just be swapping out multiple bad drives and not realize it.

 

Anyway, hopefully it's not the floppy controller, but it's always a possibility. If you don't have a Gotek, and were thinking you might want to get one, this would be a good time as it would help you troubleshoot this drive issue a little further.

 

Ah, I see Zogging Hell just suggested the same thing. A day late and a dollar short; that's the story of my life!

 

Edited February 21, 2020 by bfollowell

[Randy]

Hey JP977, did you have any luck with figuring out the problem?  I seem to be having a similar problem as well, still working on it though...

[tjlazer]

I suspect it's the drive that is either dirty or bad.  The caps can go bad as well.  I have had a few original STF drives fail on me over the years.  Problem is it's really hard to repair them or recap as the drive is really hard to take apart and put back together.

[Randy]

tjlazer, there is a video showing how to work on one of these drives, really not all that hard if you have any electronics experience.  However, making the determination of whether its the drive or something else on the board (3 chips) is a bit of a problem unless you have known good drives, in which case it could very well be a chip problem which is not all that unusual.

[Randy]

Actually, its a slide presentation on exxos site, pretty good one too!

[+tf_hh]

On 2/21/2020 at 9:55 AM, JP977 said:

Small update on this topic. I followed exxos' guide on recapping the PSU and I even got the PSU checked by a professional afterwards but the problem is still there: the floppy drive led lights up, it tries to read the disks and after a while it returns a general error message. This happens both with the original drive and a replacement one I got off Ebay.

 

Any suggestion on what to try next? Could it be the motherboard caps or maybe floppy control chips?

 

Unfortunately the 1040 STE has several problems with DMA - and the FDC (floppy disk controller) is also affected. Luckily none of my 1040 STE has this issue, but I have had a lot of my table in the last years. You will found detailed informations here.

 

Some of the hints from Exxos are useful, some not. My best way to make the floppy part running well is changing the DMA chip and soldering the 10K pull-up resistors to the databuss between DMA chip and FDC (see Exxos linked page above). From my personal experience, you don´t really spend much money for the "good" DMA chip - just take another from any 260, 520 oder 1040 ST/STM/STF/STFM or Mega ST. All these machines have no problems with the DMA chip, so an exchange of them can help - also when both DMA chips are called "bad DMA chip". If you have access to a bunch of STs, just let the chips rollate and in junction with the pull-up mod you have a big chance to solve this.

 

Be careful with harddisks or harddisk-emulations. The DMA issue may appear here, even if floppy part works good then. That´s the reason why the 1040 STE is mostly only used as a gaming / demo watching machine with a Gotek or HcX emulator.

[Randy]

I had problems with 1040 STFM with floppy drives and wasn't sure if it was the drive or the big 3 (DMA, WD1772, sound chip).  Luckily in the sale was an unformatted Gotek that I formatted with help from this site and poster here https://www.exxoshost.co.uk/forum/viewtopic.php?f=12&t=593

 This finally worked for me and I was able to determine that both floppy drives were not functioning and, more importantly, that the computer was fine.  In your position, I would go the Gotek route and see if that works and therefore dismiss any problems with the motherboard.  Or you can download a copy of the service manual and do a bit of detective work to see if the big 3 are at the root of the problem, that was where I was going next if the Gotek had not worked.  Now it is on to finding a good floppy to use for my disk collection!

[JP977]

Hello everyone, as I previously stated recapping the PSU unfortunately didn't fix the problem. I then got my hands on another STE motherboard (a non-working one, but for other reasons) and used its WD1772 as a replacement but still nothing. I am 100% sure it's not the floppy drive as I also used a compatible brand new one with still boxed disks and the problem is still there. Now, as some of you suggested, I'm thinking about getting a Gotek. I guess it won't be wasted money as sooner or later I want to get a working Atari ST and I'll need a Gotek anyway. Do you think it might solve the problem? Should I try replacing anything else first? Don't want to spend a lot of money on this motherboard otherwise I might as well get a 100% working STF off Ebay for roughly 150 euros.

 

Thanks again for the suggestions!  

Edited May 10, 2020 by JP977

[bfollowell]

It depends. You say you’re 100% certain that your floppy drive isn’t the issue, but you’re still having floppy issues.

 

If you’re having floppy issues, and you’re certain it isn’t the drive, then something else in the computer is causing the problems and replacing the drive with a Gotek isn’t going to make those problems just go away.

 

Personally, I don’t think you can be so certain unless you’ve seen the drive work somewhere else. There are no “new” drives anywhere anymore. Even just out of the box and never used, drives are likely at least a decade old, and boxed means nothing for floppy media. They’re years and years old as well. The drive and disks could both have gone bad just sitting there for years.

 

Still, if you know they’re good, and they’re not working in your ST, then there’s something wrong in your ST, and there will still be something wrong in your ST when you install the Gotek.

 

[Randy]

The suggestion for trying a Gotek is that we KNOW they are good once formatted properly, so if that works you KNOW it not the computer and is something with the disk drive.  I went through this process myself with a couple of drives, none would work, so I tried the Gotek, and boom, it worked.  Rand some programs off of it so the computer was good to go, and by default, the drives had to be bad.

[bfollowell]

Oh, I agree with you, but JP977 said he’s 100% certain that the floppy drive is good. His logic seems flawed to me, so I’m not convinced, be he is. Personally, I think there’s a good chance a Gotek will work, which would mean the computer is good and there’s a problem with the drive. I guess time will tell.

[JP977]

Quick update on this issue. I got a Gotek and as I suspected, it still doesn't work. The device is set up correctly but when I select the A: drive all it shows is a series of files and folders with gibberish text. This also happened twice with the native and the replacement floppy disk (most often the system just says that the disk is unreadable). At this point it will probably be easier to just get a new working ST (and this time I'll get an STF, the same version I had 25 years ago) and sell this one for spare parts.

[+tf_hh]

25 minutes ago, JP977 said:

Quick update on this issue. I got a Gotek and as I suspected, it still doesn't work. The device is set up correctly but when I select the A: drive all it shows is a series of files and folders with gibberish text. This also happened twice with the native and the replacement floppy disk (most often the system just says that the disk is unreadable). At this point it will probably be easier to just get a new working ST (and this time I'll get an STF, the same version I had 25 years ago) and sell this one for spare parts.

 

Did you mention my post here?

 

I´m pretty sure it´s the well-known DMA problem.

 

[JP977]

3 hours ago, tf_hh said:

 

Did you mention my post here?

 

I´m pretty sure it´s the well-known DMA problem.

 

Thank you tf_hh, that's actually the very last thing I might try before giving up. I looked around a bit and found this:
https://www.exxoshost.co.uk/atari/last/DMAfix/index.htm

 

Any other guide you would reccomend?

[JP977]

Updating this thread in case someone with the same problem stumbles into it. As tf_hh stated, this seems to be a common problem with STE boards. Exxoshost's website has a lot of information concerning it. Apparently, the easiest solution is to replace the CPU with one of the MC68HC000EI** series. I purchased one on E-Bay for about 4 euros but since it's shipped from China it will take a while to get here. I'll let you know if it solves the problem. 

[Randy]

Thanks JP!  As I have an STe on the way, this may become helpful, thanks!

[+tf_hh]

On 5/17/2020 at 4:25 PM, JP977 said:

Thank you tf_hh, that's actually the very last thing I might try before giving up. I looked around a bit and found this:
https://www.exxoshost.co.uk/atari/last/DMAfix/index.htm

 

Any other guide you would reccomend?

 

Hmm, my personal experiences somewhat from the things written by Exxos at the linked page. I got nearly never luck with exchanging the CPU to a CMOS type. It´s a little bit better, but more effective are changing the DMA (see above in my post) and the pull-up resistor array.

 

[TGB1718]

Just found this thread, I have similar problems with floppy drives, little used for maybe 20+ years, however I did make some images

of some more important floppys, I recently tried to use both my ST's a 520 STM and a 1040 STFM and neother machine would reliably

read any disks eventually not reading any, I have 3 different floppy drives and none semmed to work.

 

I cleaned heads, checked cables, wiring etc. and all seemed fine, so I put it down to the floppy drives failing due to age, so I 

have just bought a GOEX drive, on hooking that up after loading images that work fine on STeem I get the same issue, nothing

loads, I see the LED on the GOEX come on just like the real floppy's also I hear little beep sounds from the GOEX speaker.

 

At this point I'm considering that there is something wrong with both ST's. I have an older PC that I use to image the floppys,

so I set the BIOS to tell it it was a 720K floppy attached, and managed to use one of the old floppy drives to read a floppy disk

on it, the disk was Autoroute and was formatted on a PC that I used under PC_DITTO, I copied all the files off the floppy to

the hard drive, so reading was fine, I thought I would try formay the floppy, big mistake, I didn't realise it was a single sided

floppy and the PC format failed, once that happens, there seems to be no recovery, nut at least I know that floppy drive is ok.

 

Back on the 1040, I managed to read the directory of a couple of disks, but thats all I can do, if I try to open any text files

or run programs, there seems to be no head movement and obviously it fails with disk errors.

 

I'm going to "scope" the signals tomorrow to see if the correct voltage levels and switching signals are there.

 

My question is does this sound like it could be solved by the resistor pack addition mentioned earlier in this thread,

as it seems to only mention this working on an STE.

 

Of course if anyone else had seen/had this problem on an STM and 1040 and resolved it, that would be great.

[Randy]

One thing I have noted and spoke about before, is the DSDD drives I have tried, mostly Epson 380 drives, have all worked when cleaned and recapped.  The problem has been their reliability, in other words, when running a bunch of floppys, some which were obviously bad/defective, the drives would eventually start to fail on every floppy, including good one the drive had read before.  This would required taking the drive out and cleaning the heads again, this would always fix the problem until the next "dirty heads" would appear.  I should also note that most problems seem to be with the top head, less so on the bottom head.  However, I did manage to get an HP-branded Epson 340 HD drive that I made to read/write in HD format on my Mega STe and it has been far more reliable reading disks with only one cleaning needed after reading around 200 floppys I have picked up.  Also, disks that failed to read on a "clean" Epson 380 would be read fine on the Epson 340, go figure.  I still get bad floppy reads on some disks, probably really just bad/dirty floppy disks.  In my trials, it would appear that the Epson 340 drives are more reliable at reading disks than the Epson 380, not sure why, but that has been my experience.