Franc Zabkar wrote:
On Sun, 19 Apr 2009 00:15:56 -0400, Yousuf Khan put
finger to keyboard and composed:

Anthony K. wrote:
Is it possible to get a vintage 5.25" PC floppy drive connected to a
modern PC with no floppy controller and just USB/FireWire inputs? Do IDE
5.25" floppy drives exist? If so, I could drop one into a USB enclosure.
Is there an adapter that would let me connect a floppy drive to an IDE
interface?

My specific machine is a Macintosh so I'm certain there are additional
BIOS issues, but I figure, as long as I am able to get the drive mounted
via USB, I could run Windows or just virtualize DOS in order to see the
drive properly.


Well, I'm sure it's possible to get it to work in a USB, but the floppy
controller interface is not the same as IDE, it predates the IDE
interface by more than a decade. You won't be able to plug a floppy into
an IDE interface. However, there are direct floppy to USB drives
available these days, most seem to be of the 3.5" floppy variety.

Here's some examples from one vendor:

Canada Floppy Disk Drives, Floppy Drive, External Floppy Drives, USB
Floppy Drive at TigerDirect.ca
http://www.tigerdirect.ca/applicatio....asp?CatId=287

Yousuf Khan

If you can find a case with a standard +5V and +12V supply, plus the
standard 34-pin connector, then you should be able to remove the 3.5"
FDD and replace it with a 5.25" drive. You will need an adapter for
the power connector, though. I suspect, however, that the 3.5" drive
in the external enclosure may not use a standard PC interface. See the
following pinouts:

http://pinouts.ru/Storage/5_12_floppy_pinout.shtml
http://pinouts.ru/Storage/26pin_micr...y_pinout.shtml
http://pinouts.ru/Storage/InternalDisk_pinout.shtml
http://pinouts.ru/DiskCables/Floppy_pinout.shtml

Be wary of USB powered enclosures as these may not have enough power
(500mA max at +5V) for a 5.25" drive. Also be aware that PC FDDs are
jumpered as drive 1, not drive 0, so you will either have to find a
cable with a twist, or determine how to re-jumper your drive.

There are some additional problems:

- Some 3.5" USB floppy do not have a Shuggart bus (mine has not).
Youd id mention that.
- Many 5.25" Floppies have a very low resistance (120R) pullup on
/step /date and, I think, /WR, while most 3.5" floppies just draw
one standard TTL load (1.6mA). You may need singal drivers or need
to find and cut the pullups.
- HD 5.25" floppis run at 360rpm instead of the 300rpm all 3.5"
floppies run at. That may confuse the controller and may
make access impossible.

Arno