DRIVPARM Must Be Used with Tandy 1000HX, 1000TX, 1400LT/HD (80434)

The information in this article applies to:
    Microsoft MS-DOS operating system 5.0
    Microsoft MS-DOS operating system 5.0a
    Microsoft MS-DOS operating system 6.0
    Microsoft MS-DOS operating system 6.2
    Microsoft MS-DOS operating system 6.21
    Microsoft MS-DOS operating system 6.22

This article was previously published under Q80434


Tandy Corporation has confirmed that Tandy 1000HX, 1000TX, 1400HD, and 1400LT computers with 3.5-inch disk drives may not format disks properly after upgrading to MS-DOS 5.0 or later.

For proper floppy drive use after installing MS-DOS 5.0 or later, the DRIVPARM statement must be used with the /I switch in the CONFIG.SYS file.


After installing the MS-DOS 5 Upgrade on a Tandy 1000HX, 1000TX, or 1400LX computer, the computer attempts to format a 3.5-inch disk as a 360K disk.

Using other size parameters results in the following error message:

Invalid Parameter, This Mode Not Supported, Formatting 360K
According to Tandy Corp., this problem can be worked around by using the /I switch with a DRIVPARM statement in the CONFIG.SYS file. Using DRIVER.SYS or DRIVPARM alone will not eliminate the problem.

The following statement should be placed in the CONFIG.SYS file:
   drivparm=/d:[drive number] /f:[size of drive] /i
The /I switch indicates an electronically compatible disk drive.

The Tandy products included here are manufactured by a vendor independent of Microsoft; we make no warranty, implied or otherwise, regarding these products' performance or reliability.


"Microsoft MS-DOS User's Guide and Reference," version 5.0, pages 455-456

Modification Type: Major Last Reviewed: 5/12/2003
Keywords: KB80434