Using 720K or 1.44 MB 3.5-Inch Disk Drive with MS-DOS (60091)

The information in this article applies to:
    Microsoft MS-DOS operating system 3.1
    Microsoft MS-DOS operating system 3.2
    Microsoft MS-DOS operating system 3.21
    Microsoft MS-DOS operating system 3.3
    Microsoft MS-DOS operating system 3.3a
    Microsoft MS-DOS operating system 4.0
    Microsoft MS-DOS operating system 4.01
    Microsoft MS-DOS operating system 5.0

This article was previously published under Q60091


Many users wish to install 3.5-inch floppy disk drives in their systems. Currently, there are two popular varieties of the 3.5-inch floppy disk drive. MS-DOS Version 3.30 supports the 720K and 1.44 MB 3.5-inch floppy disk drives. Listed below are some general guidelines to remember when selecting a 3.5-inch floppy disk drive.


The disk controller for your computer must support the type of floppy disk drive you want to install.

The ROM BIOS also needs to support the floppy disk drive. Many of the ROM BIOS versions available today DO NOT support the 1.44 MB floppy disk drives. (This is because the 1.44 MB floppy disk drive was first introduced by IBM on their PS/2 systems, and the ROM BIOS of IBM's PC/AT systems do NOT support 1.44 MB floppy disk drives.) More versions of the ROM BIOS do support the 720K floppy disk drive. Check with the original equipment manufacturer (OEM) of your computer to find out what version of the ROM BIOS is required to support a 1.44 MB or 720 MB 3.5-inch floppy disk drive.

With an AT system, a setup program is run to tell the ROM BIOS what types of floppy disk drives are hooked up. If the setup program supports the floppy disk drive, the DRIVPARM command (or the DRIVER.SYS command) is not necessary. This is the preferred way to install the floppy disk drive.

If the floppy disk drive is being installed on an XT system, or if the drive type is not supported under the AT setup program, you must use either the DRIVPARM or DRIVER.SYS command. Under MS-DOS Version 3.30, the DRIVPARM command is not functional, and therefore, the DRIVER.SYS command must be used. An update to MS-DOS Version 3.30a is available that allows the use of the DRIVPARM command.

The following are some examples of using DRIVPARM and DRIVER.SYS:
   DRIVPARM=/d:01 /f:02           ; For a 720K floppy disk drive on B:
   DRIVPARM=/d:01 /f:07           ; For a 1.44K floppy disk drive on B:
   DEVICE=DRIVER.SYS /d:01 /f:02  ; For a 720K floppy disk drive on B:
   DEVICE=DRIVER.SYS /d:01 /f:07  ; For a 1.44K floppy disk drive on B:
The DRIVER.SYS device driver creates an external reference to the floppy disk drive if it is configured correctly. DO NOT Reference Drive B; otherwise, the floppy disk drive will be installed incorrectly. If you have a hard disk Drive C and you set up DRIVER.SYS, it will create a reference of D: to the 1.44 MB disk in Drive B. Use Drive D to access the 1.44 MB floppy disk drive.

Modification Type: Major Last Reviewed: 11/25/2003
Keywords: KB60091