Tandy 1000 TX Video Memory Uses the High Memory Area (HMA) (74655)



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 Q74655

SYMPTOMS

When you try to load HIMEM.SYS on a Tandy 1000 TX, you receive the following error message:

VDISK Memory Allocator Already Installed: XMS Driver Not Installed.

CAUSE

The Tandy 1000 TX, an 80286 machine, uses the high memory area (HMA) for video memory. According to the Tandy Corporation, video memory is hard-wired to the A20 line. As a result, HIMEM.SYS does not load.

Third-party XMS memory managers also encounter a similar message.

MORE INFORMATION

The Tandy 1000 TX is manufactured by Tandy Corporation, a vendor independent of Microsoft; we make no warranty, implied or otherwise, regarding this product's performance or reliability.

Modification Type: Major Last Reviewed: 5/12/2003
Keywords: KB74655