IBM PC/XT Clone and 1.44MB FDD

From: Fred Cisin <>
Date: Wed Mar 24 13:10:27 2004

> At 12:21 PM 3/24/04 +0400, you wrote:
> >Hi,
> >I've got a generic PC/XT 8088 clone (contains NEC processor) with no HDD
> >and two 5.25" FDD. Needless to say that the media as well as the O/S (M$
> >DOS) is not available in my local market.
> I was wondering if it's
> >possible to:
> >(1) Install a 3.5" 1.44MB FDD in it.

On Wed, 24 Mar 2004, Joe R. wrote:
> There were plenty of aftermarket disk drive controller cards that had
> built in BIOS that supported 1.44 drives. Other than that you can use the
> DRIVER.SYS program in MS-DOS to handle the floppy.

The stock disk controller will handle 720K; but NOT 1.4M.
You can even get away with using a 1.4M drive for the 720K.
For use with 720K, the only software needed is to let the OS know. That
can be done with DRIVER.SYS, or DRIVPARM. DRIVPARM will NOT work with the
IBM BIOS. DRIVPARM is present in MS-DOS, and is present but undocumented
in PC-DOS. DRIVPARM is incompatible with the IBM BIOS.

If you NEED 1.4M, then you will have to replace the floppy disk controller
with one that supports the higher data transfer rate (500K bps), and
software to replace INT13h of the BIOS. Some of those boards include
their own replacement BIOS in a ROM chip on the board.The most popular and
sought after of those boards is the Micro-Solutions "Compaticard"

Grumpy Ol' Fred
Received on Wed Mar 24 2004 - 13:10:27 GMT

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