Yay, now I need some Osborne boot media!

Fred Cisin cisin at xenosoft.com
Mon Nov 24 16:44:48 CST 2014

On Mon, 24 Nov 2014, Chuck Guzis wrote:
> One of the easier methods of crossing the old-new divide is to replace
> or add a 3.5" floppy drive to the XT and use 2D (not high-density) media
> to exchange.  Leave the other 5.25" floppy where it is.  Of course,
> you'll need the header-to-edge adapter and the power cable adapter, but
> AFAIK, they're still available--as well as drive bracket adapters.
Once you solved the power connector issue, you could usually find cables,
or . . .
use a fairly long AT cable, but use the middle floppy connector for the
FDC!, the FDC connector for the 3.5" drive, and the end floppy connector
for the other floppy drive.

> Later versions of MS-DOS (I don't recall exactly when, but I think it
> was around 3.3 or earlier, have a DRIVER.SYS installable driver to
> handle the full 720K)--otherwise, you may be restricted to writing 360K.

THAT would be version 3.20   of bothe MS-DOS and PC-DOS.
They also had DRIVPARM as a CONFIG.SYS "command", that would reconfigure
without adding another drive nor driver in [precious] RAM.  But, that was
not documented in the PC-DOS manuals, and for reasons as yet unexplained,
would not work with the real IBM BIOS ROMs, although it did work [with
either PC-DOS OR MS-DOS] with Award, Phoenix, and several generic BIOS

Also, SOME non-generic OEM versions of 2.11 that were put out with laptops
supported 720K drives.

> The actual type 3.5" drive doesn't matter much--you can use an HD or DD
> drive, so long as it's media-sense and not host-directed for density
> (almost all are) and you use DD disks (or cover the media type aperture
> on the floppy.)

Well, the "1.4M" media and the "720K" media was slightly different.
600? Oersted V 720? oersted, so it was close enough that you could usually
get away with using the wrong one.

Grumpy Ol' Fred     		cisin at xenosoft.com

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