A310 floppy drive alternatives

[dominicbeesley]

The floppy drive on the A310 I got from the Bradford show last year never had a good floppy drive and my attempts at fixing it have not made matters any better - I've pretty much knackered the head alignment in trying to fettle them, though they were pretty much goosed anyway. I'd not realised how difficult it would be to substitute the drive or I might have proceeded with more caution.

The problems seem to be several:
1) location of the LED - I can solve
2) location, shape and position of the eject lever - more difficult but not insoluble
3) drive/ready signals seem to be different

I'd really like to get it back working with a real floppy drive not a Gotek or other substitute - I may well fit one as a second drive though.

Are there any known readily available substitutes?

If not, is there any document describing what signals the A3xx series want from the drive. I must have a drive in my collection that can be persuaded to cooperate even if I have to do some metal bashing to get the eject button lined up

D

[baz4096]

The A3xx series uses the same floppy as the Master Compact, so at a pinch, and if you don't mind sacrificing a Compact PSU drive unit drive (if you have one), you can use one of those. Sony MP-F63W-00D is what you're after. This manual might be similar: http://bitsavers.trailing-edge.com/pdf/ ... _Sep85.pdf, but I've been unable to find the F63W version. F53W appears to be a slower access time CMOS version vs the faster TTL F63W. https://manualzz.com/doc/19851976/sony_ ... ochure.pdf
I don't know about any alternatives I'm afraid.

[jms2]

I’m in the same position myself, but similarly haven’t found an alternative. The real drives are very rare and so, it seems, is much documentation. It’s surprising how difficult it is to find old floppy drives.

[dominicbeesley]

Thanks both,

Thanks for that datasheet Baz, it should help - already its helped me work out why I was getting inconsistent results from the RF test-points, they're difference signals, not one per-side. That may help me to realign the drive. I've bent the spring (flat copper/brass) that holds the top head in place...the clamping screws sheared off as soon as I tried to free them off to allow me to rework/realign it! The pinout may give me further clues as to what change/ready signals are required too.

It sounds like I will need to endeavour to fix what I have though if they are that rare. I have a newer Sony drive that has slightly different heads but they look like they may transplant. I'll come back with pictures when I work up the enthusiasm to try some transplant surgery....

D

[nicf82]

Snap @dominicbeesley that is exactly what happened to me, bent the spring then snapped the heads of the screws

I would be interested to hear if you find another drive whose head can be used, or a way to shoehorn in a modern drive!!

Nic

[jms2]

This is like a self-help group, it's excellent!

Would I be right in thinking that the copper-coloured spring plate simply holds the head down against the disc, and (within reason) doesn't need to be too precise provided that the head is actually kept in contact? If that's the case, is it possible to somehow bend it back down while in situ? I did actually try this, but it didn't seem to help.

Or... could adding a small weight to the arm cause it to get pulled down more and compensate for the permanent set of the spring?

[nicf82]

This is like a self-help group, it's excellent!

is it possible to somehow bend it back down while in situ?

I did try the same thing but it did not work for me either. I bent it down enough to get it to sit in what looks lie the right place but unfortunately I still just keep getting Disc Error 0 when I try to verify a disc on that drive. I am assuming it is somehow out of alignment.

Cheers!
Nic

[jms2]

Same here. The thing about alignment though is that there's no way to adjust it, and also you'd think the drive would be able to read discs that it had formatted itself, even if misaligned. So this leads me back to the simple "not close enough" theory. I don't really know what I'm talking about though!

[dominicbeesley]

I think in bending it about must have upset the azimuth alignment so that it is not exactly tangential to the centre or possibly the heads aren't resting exactly flush against the surface.

I really should try and do some proper experimentation by writing to and reading back from each surface. If they are both not working then it is the pressure of the head pressing together that is out. If only on side is off then it is my fiddling with that head?

I will need to clear space on my workbench and hook the drive up to a Beeb where I can do some low level poking at the disc controller...