floppy low level format question

From: Fred Cisin <cisin_at_xenosoft.com>
Date: Fri Jun 11 17:52:36 2004

On Fri, 11 Jun 2004, Pete Turnbull wrote:
> So long as it's FM/MFM it's pretty much the same for any controller --
> otherwise disks wouldn't be so interchangable :-)

With a few quirks and a few exceptions, such as Amiga, which is MFM, but
is NOT an "IBM 3740"/"WD" style sector.

> If you want an external floppy, why go to a lot of effort when all you
> need is one of the old cards that had an external connector? It's
> normally a 37-pin D-connector, with a few pins used to supply the
> power. Of course they're ISA cards, so you'd need a machine with ISA
> slots, but your reference to "ISA bus hang-ups" implies you have that.

Some have power on the DC37, some don't.
The IBM 5150 FDC did NOT supply power on the external
floppy connector. When IBM sold an external 3.5" 720K
drive for it, there was a second cable to go through a
hole in the back and connect to the power supply


> You also need to be able to set the card to be the second floppy
> controller (but most of the ones with external connectors have that
> capability) or disable the on-board floppy controller (if there is one
> -- but most older boards can do that too).

or just cable the existing controller to an external connector.
IBM had an adapter for AT's and one for PS/2's for that.


There was once a serial external "PC 5.25 drive" for Macintosh!
It was actually a floppy drive and an AMPRO littleboard
in a case with serial port connection. When coupled to
a Mac, and running its software, it could read PC and
some CP/M diskettes. Just like any other computer connected
to the serial port. But Mac users would NOT buy a PC
compatible computer for doing their file transfers, so
it was sold as being a "smart disk drive"

--
Grumpy Ol' Fred     		cisin_at_xenosoft.com
Received on Fri Jun 11 2004 - 17:52:36 BST

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