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Mike Chambers
October 18th, 2006, 12:09 AM
there is an interesting page i found that says 1.44 MB 3.5" floppy drives can be used on a 360 KB controller card.


You can install a 3.5-inch 1.44 MB FDD in nearly any 286 or later computers and some late-model XT clones, although the drive may be recognized only as 720 KB. If that occurs, use 720 KB (DD) diskettes in that drive. In theory, you should also be able to install a 3.5-inch FDD in a PC- or XT-class system and use it as a 360 KB FDD. In practice, this works on some PC- and XT-class systems, but not all. For reasons that are not clear to us, some old systems refuse to recognize the 3.5-inch drive. If that occurs, your only alternative is to locate an actual 5.25-inch 360 KB drive and use it to do the transfer.

http://safari.oreilly.com/059600513X/pchardnut3-CHP-6-SECT-6


maybe i'm the only one who didn't know this, but i thought i'd post it.

dongfeng
October 18th, 2006, 12:33 AM
I tried it a while ago on my XT. It worked perfectly but at 720kB :)

Mad-Mike
October 18th, 2006, 02:30 AM
My XT is still going strong on a 16 bit controller with dual 1.44M floppies, reading them at full 1.44M capacity, go figure. I have not been able to get my 360K drive working on the same controller, nor do I have a 720K availible to me at the moment. Not that it matters, I don't even really have a need to format the diskettes on that computer anyway, especially with a good 1.44M drive on my newly assembled laptop always handy.

Mike Chambers
October 18th, 2006, 08:28 AM
huh... interesting... i've tried 1.2 MB 5-1/4" drives and 1.44 MB 3-1/2" drives on my 8088 with a 16-bit controller and it never has worked. all it does it make the drive motors spin and turn the LED on once it tries to boot.

i've tried both an old mid-late 80's western digital 16-bit controller (MFM/floppy) and a newish DTC 16-bit controller (ISA/floppy) and neither work. i know the cards aren't bad, the WD works in my 286 and the DTC works in my 386.

Mad-Mike
October 20th, 2006, 05:57 PM
I really think with my computer it's the controller and drives. I've mainley stuck with the same TEAC floppy drive for the task, I think the other one is possibly a Panasonic, both are 1.44M and read 1.44M diskettes, but neither will format them.

The most noticeable thing about starting an XT from the 1.44M drives though, at least my old one (I have an older 64K-256K model board I'm using these on, maybe IBM changed something that blocked this glitch later on), is that boot times are REALLY Slow for an XT, it sometimes can be a minute or two for it to boot into DOS off a 1.44M floppy, but it pulls it off.

I think it has something to do with the controller I'm using too, since it seems to not be able to do it on just any controller card. I'll go pop it out and take a look see, and get the drive models while I'm at it.

nige the hippy
October 21st, 2006, 09:01 AM
huh... interesting... i've tried 1.2 MB 5-1/4" drives and 1.44 MB 3-1/2" drives on my 8088 with a 16-bit controller and it never has worked. all it does it make the drive motors spin and turn the LED on once it tries to boot.

Once upon a time in the dim and distant past I had exactly this prob, now I can't remember how, and it would take a bit of trying out, but I think it was all down to jumpers (or even actually soldering a wire, bridging terminals on the connector) on the 3.5" drive, as the old controller didn't provide quite enough drive-select / motor-on signals - I could well be completely addled & talking rubbish, but it might give you a clue.