How to make an external 5.25" floppy drive?

June 2, 2005 12:24 PM

Does anyone know (or can think of) any way to make an external 5.25" floppy drive? (preferably USB or wireless, for use with PC/Windows systems).

I'm quite at home with a soldering iron, but I don't know much about what is compatible with these old drives.

I'm not after "make an extension of the PC internal floppy cable" answers, as I'm looking to make an external drive that can be plugged into a computer or laptop that has no special hardware, and without the use of a screwdriver.
Likewise, "put a miniature pc with a wireless card in the external enclosure with the drive" is a useful solution if you know of any uber-miniature dirt-cheap PCs to do it with, but currently I don't. (Let me know if you do :-))

Does anyone know if the adaptor inside a USB external 3.5" floppy drive would work if swapped out with a 5.25" drive? (I'm guessing the adaptor chip wouldn't have 5.25 detection or specs, but it seems the closest thing to a chance)

Is there anything like the IDE-to-USB adaptors that would work for floppy drives?

Any other ideas?

Thanks

posted by -harlequin- to computers & internet (10 comments total)

Your best bet might be a usb-scsi converter like this one along with an external scsi floppy drive.
posted by Lazlo Hollyfeld at 1:15 PM on June 2, 2005

IDE-to-USB adapters are easy to find; there are some on the site Lazlo linked to. You can often find them sold as "external hard drive enclosures". The 3.5" adapter should work fine. I doubt the firmware to control the drive is on the adapter--it's probably built into the drive assembly--so a 5.25" drive should look just like a 3.5" drive to that hardware. I'm concerned you might have a problem with power: is USB going to be sufficient to power that big drive? If this is an issue, it should be easy to rig up an old power supply....
posted by mr_roboto at 1:50 PM on June 2, 2005

mr_roboto, but floppy drives aren't IDE.
posted by zsazsa at 2:22 PM on June 2, 2005

I am almost certain that floppy drives are not IDE devices. They use different connectors, and plug into different sockets on the motherboard.

My guess is that a USB 3.5 inch floppy could be sacrificed and hooked to a 5.25 drive since they use the same physical interface, but their may be intricacies in the way the floppy protocol is handled over USB that would create problems.
posted by Good Brain at 2:32 PM on June 2, 2005

Ok, it looks like most, if not almost all USB 3.5" floppy drives made nowadays are direct USB to drive mechanism controllers. Once upon a time, though, the company SMSC made a USB Floppy disk controller. If you can find an older USB floppy drive with this chip that used it to bridge a standard floppy to USB, you could cannibalize it and use it. Some Usenet research leads me to believe that this exact USB floppy used the chip -- maybe you can find it still. Or you can find the chip by itself and wire it up yourself according to this handy-dandy PDF.
posted by zsazsa at 2:47 PM on June 2, 2005

I just remembered those old Backpack drives by Micro Solutions that plugged into the parallel port. If you can find one, your driver support will probably be limited to DOS only, or if you're lucky, Windows 95 or 98. I also found a Micro Solutions USB drive that looks old and chunky enough to just be a standard floppy drive in an enclosure with that chip I mentioned. However, it looks identical to their 3.25" parallel port model, so I may want to contact Micro Solutions to see if their model 14352 looked exactly like that. If it did, that may be a good drive to cannibalize.
posted by zsazsa at 3:03 PM on June 2, 2005

I'm interested to hear why you'd like to do this, since 5.25" disks aren't exactly the most reliable media in the world. It would be much easier to copy all of your 5.25" disks to image files using a normal 5.25" drive once, and store the images locally or on a CD.

Something like Daemon Tools ought to be available to mount these images as if they were physically attached on Windows, and with Unix-based systems you can use a loopback device to do the same thing, thus satisfying older software that insists on reading from a 5.25" drive.

So, I'm just curious, what are your desired results? There may be a simpler solution.
posted by odinsdream at 5:27 PM on June 2, 2005

Lazlo Hollyfeld writes "Your best bet might be a usb-scsi converter like this one along with an external scsi floppy drive."

Beat me too it. As a bonus you could hang as many drives you wanted off the same usb connection.
posted by Mitheral at 6:14 PM on June 2, 2005

I'm not convinced that this will work - as I understand it, different types of drive have completely different controllers; just connecting a 5.25" drive to a 3.5" controller probably won't do anything (or at least anything good!).

I know that you've stated that you want it to work without additional hardware, but check out Individual Computers - mostly Amiga hardware design/production, but Jens has apparently been involved in the C-One project, and the product of interest here is the "Catweasel mk3 PCI Flipper" which allows the connection of virtually any drive type...

Perhaps you can get some help from him, or maybe snag some ideas from the Catweasel...
posted by Chunder at 1:55 AM on June 3, 2005

Well, it doesn't look like it's going to be easy. Thanks for the help and links. I'm going to investigate as time and money allows.

The datasheet zsazsa tracked down indicates the chip supports 640, 720k, 1.2M, 1.44M, which suggests it supports HD 5.25" floppies, but not DD (360K). I'm pretty sure some of the floppies are DD, so that's a bit of a blow. It may be worth trying this route anyway,, since I imagine an old enclosure with this chip should be really cheap (as in, a few bucks).

I've never looked into scsi 5.25" drives, since I only have old drives from PCs, that sounds like a good idea too. Don't know whether it will work, but I don't know why it wouldn't work, only one way to find out :)

Odinsdream:
Regarding why, there are a few practical reasons (such as a bunch of stuff on floppies at my parent's place on the other side of the world, where the only computer I have with me is a laptop), but the bigger appeal is that it's just so much more useful to have one of these drives portable and available for any machine, at any time, at my convenience, than it is to have to mess around setting up a computer.

Other practical reasons include that support for these floppies is being dropped from some chipsets, soon it will nolonger be possible to hook up a drive to your computer unless it's an external, and I don't like the idea of a media becoming permanent irretrievable because I didn't get the parts while you still could.

There are also so many of these floppies kicking around in different places that setting up for one session to go through them isn't going to work - more will always found as houses get cleaned and old boxes get opened. And I suspect that other people will have similar reasons to borrow it.
posted by -harlequin- at 3:46 PM on June 5, 2005