Most probably your Mitsubishi drive is out of alignment. Pretty much the first (and maybe sole) symptom of a misaligned drive is that it's the only one able to read the disks it writes - just picture it as the heads' track 0 position is slightly shifted from the normal position, so they actually write with a slight offset that they can re-read fine, but that is not the 0 track position every other properly calibrated drive expects (or writes).

Realigning floppy drives is not as complicated as it's often said to be. If you have a steady hand, a little patience and ImageDisk 1.19 for DOS, it's actually pretty easy. You do not need some specific realignement disk or anything - any Microsoft official floppy was usually duplicated using highly precise hardware from what I've read, and if you don't have any, just any other commercially released floppy should be good enough, or so it was in my experience. EDIT: incomplete/bad advice, see posts below

I have meant to write a guide here on Vogons for quite some time but haven't yet done so. I definitely should, because it's a recurring question and I easily fixed plenty of floppy drives, and when the subject is brought up a lot of people mistakenly think this is way harder than what it actually is. Anyway if you have any question, just shoot and I'll try to help.

Boohyaka wrote on 2023-05-20, 22:11:

Most probably your Mitsubishi drive is out of alignment. Pretty much the first (and maybe sole) symptom of a misaligned drive is that it's the only one able to read the disks it writes - just picture it as the heads' track 0 position is slightly shifted from the normal position, so they actually write with a slight offset that they can re-read fine, but that is not the 0 track position every other properly calibrated drive expects (or writes).

Realigning floppy drives is not as complicated as it's often said to be. If you have a steady hand, a little patience and ImageDisk 1.19 for DOS, it's actually pretty easy. You do not need some specific realignement disk or anything - any Microsoft official floppy was usually duplicated using highly precise hardware from what I've read, and if you don't have any, just any other commercially released floppy should be good enough, or so it was in my experience.

I have meant to write a guide here on Vogons for quite some time but haven't yet done so. I definitely should, because it's a recurring question and I easily fixed plenty of floppy drives, and when the subject is brought up a lot of people mistakenly think this is way harder than what it actually is. Anyway if you have any question, just shoot and I'll try to help.

Hmm, that might be possible, I did clean the drive (put new grease on the steppe motor and some lube on the carrage) but didn't remove the steppe motor (only the readhead) from what I've seen it does take a long time. I do have screws on top of my readhead, but I think fiddeling with the steppe motor might be enough I hope.

I can also change my sector 0 detector with a little nob, do I need to fiddle with that (see photo's).

https://yourimageshare.com/ib/JR6URsBElD

https://yourimageshare.com/ib/m2tSq9w8Ds

Thanks for your time!

If you were able to access it properly then jumpers are fine.. so leave them as they were.
This is an alignment issue of course. There are three fail points:
1- Stepper motor adjustment out of place
2- Heads not aligned to each other
3- Track 0 detector out of place

Fixing 1 is easy and it's a common failure. Manufacturers even almost always expose the alignment control in a way you don't need to disassemble anything from the drive to access it.

Fixing 2, I hope you didn't unscrew the heads away from each other. It's probably more work than fixing 1, but can be done.

Fixing 3, this one can be annoying. As it usually requires more disassembly, and also can mess up other parts and introduce new misalignments if you don't know what you're doing.

I agree with Boohyaka on IMGDisk. It's a great tool for fixing this kind of stuff. Though I prefer not to sacrifice an original factory app/game disk for this mission, as probably its surface might get scratched in the process. You can use a brand new factory-preformatted disk (best), or a disk formatted in another drive that reads factory disks fine (not the best, but still good as a first step).

IMGDisk has limitations though.. and can't work in all cases of misalignment. If you're lucky, the Alignment tool can recognize the disk. If not, you're gonna have to work blind for a little while until IMGDisk recognizes it, then starts giving you those lovely beeps.

wbahnassi wrote on 2023-05-21, 09:58:

Fixing 2, I hope you didn't unscrew the heads away from each other. It's probably more work than fixing 1, but can be done.

(...)

I agree with Boohyaka on IMGDisk. It's a great tool for fixing this kind of stuff. Though I prefer not to sacrifice an original factory app/game disk for this mission, as probably its surface might get scratched in the process. You can use a brand new factory-preformatted disk (best), or a disk formatted in another drive that reads factory disks fine (not the best, but still good as a first step).

Your scenario 2 is actually not that bad, just takes a little more patience 😉 I've fully disassembled drives (including heads) in a very sad and dirty state, and was able to rebuild and realign them just fine using only IMD.

The last point is very very valid, I don't know what I was thinking as it's not even how I use to do it. Let's say it was getting late and written just before jumping into bed 😁

1. Use IMD head alignment tool with a known good drive with an "official" floppy, check around all tracks with the seeking feature that you're getting a steady read, and make sure to press H to do the same with the other head
2. Once you validated your good drive, format a blank floppy using that same drive. This will be your alignment disk to fix other drives.

ThunderEagle wrote on 2023-05-20, 22:56:

Hmm, that might be possible, I did clean the drive (put new grease on the steppe motor and some lube on the carrage) but didn't […]
Show full quote

Hmm, that might be possible, I did clean the drive (put new grease on the steppe motor and some lube on the carrage) but didn't remove the steppe motor (only the readhead) from what I've seen it does take a long time. I do have screws on top of my readhead, but I think fiddeling with the steppe motor might be enough I hope.

I can also change my sector 0 detector with a little nob, do I need to fiddle with that (see photo's).

https://yourimageshare.com/ib/JR6URsBElD

https://yourimageshare.com/ib/m2tSq9w8Ds

Thanks for your time!

You should probably start by checking the current alignment of both heads with IMD with a good alignment floppy as explained above, before doing anything. Usually the step motor is directly hooked to the bottom head 0 and you need to adjust the whole assembly, and the top head 1 can be further adjusted by loosening the two screws. So you should first check if both heads are misaligned. If it's the case, start by trying to fix head 0 readings, then once that done and if head 1 is still misaligned you can adjust it without altering what you just did to fix head 0. Otherwise I've seen quite some drives with only head 1 being misaligned and in that case you don't want to mess around the stepper motor and only fix it directly with the 2 top screws.

Boohyaka wrote on 2023-05-21, 11:39:

ThunderEagle wrote on 2023-05-20, 22:56:

Hmm, that might be possible, I did clean the drive (put new grease on the steppe motor and some lube on the carrage) but didn't […]
Show full quote

Hmm, that might be possible, I did clean the drive (put new grease on the steppe motor and some lube on the carrage) but didn't remove the steppe motor (only the readhead) from what I've seen it does take a long time. I do have screws on top of my readhead, but I think fiddeling with the steppe motor might be enough I hope.

I can also change my sector 0 detector with a little nob, do I need to fiddle with that (see photo's).

https://yourimageshare.com/ib/JR6URsBElD

https://yourimageshare.com/ib/m2tSq9w8Ds

Thanks for your time!

You should probably start by checking the current alignment of both heads with IMD with a good alignment floppy as explained above, before doing anything. Usually the step motor is directly hooked to the bottom head 0 and you need to adjust the whole assembly, and the top head 1 can be further adjusted by loosening the two screws. So you should first check if both heads are misaligned. If it's the case, start by trying to fix head 0 readings, then once that done and if head 1 is still misaligned you can adjust it without altering what you just did to fix head 0. Otherwise I've seen quite some drives with only head 1 being misaligned and in that case you don't want to mess around the stepper motor and only fix it directly with the 2 top screws.

Yes, this managed to fix my problem. The Mitsubishi drive steppe motor was slightly off causing the floppy drive to read a non-existent sector -1 instead of reading sector 0, and got a lot of mismatched tracks (basically 0 matches). I did get it working correctly working in like 10 minutes. Luckily there are plenty of Youtube tutorials out there to help me understand IMD.

Of course I tested with a original Doom2 floppy without backup 😖 (without a joke, I'm not a complete noob when it comes to retro PC's and always test things with throwaway stuff if possible, but simply never delved more into fdd drives until now).

In fact it seems like I got 2 more drives with this issue, both is which are kinda old drives. So I can save those as well.

I will probably stick to these forums and help people out here and there. Anyhow, thank you for your time, I appreciate it!