MEM/C Reports Zero Bytes with MOUSE.EXE Loaded High

• Microsoft MS-DOS operating system versions 5.x, 6.0, 6.2, 6.21, 6.22
• Microsoft Mouse Driver for MS-DOS, versions 9.x, 10.0

SYMPTOMS

When you use the MEM /C command to report the upper memory used by the Microsoft Mouse driver versions 9.x and 10.0, the MEM command may incorrectly show 0 bytes for MOUSE.EXE in upper memory.

CAUSE

This problem can occur if the line DOS=UMB is not present in the CONFIG.SYS file. The MEM command sees only programs that are loaded using upper memory blocks (UMBs). Since MOUSE.EXE can load outside the MS-DOS memory allocation chain, it may not show up in MEM's report.

STATUS

Microsoft is researching this problem and will post new information here in the Microsoft Knowledge Base as it becomes available.

MORE INFORMATION

The Microsoft Mouse driver version 9.x and 10.0 can load into upper memory automatically even if the DOS=UMB line is not present in the CONFIG.SYS file.

If the DOS=UMB line is present in the CONFIG.SYS file, memory usage in the upper memory area is reported correctly by the MEM /C command.

Steps to Reproduce Problem

1. Boot your computer with the following CONFIG.SYS and AUTOEXEC.BAT files:

   
         CONFIG.SYS
         ----------------------------
         DEVICE=C:\DOS\HIMEM.SYS
         DEVICE=C:\DOS\EMM386.EXE RAM
         DOS=UMB
   
         AUTOEXEC.BAT
         ------------------
         C:\MOUSE\MOUSE.EXE 




2. Type "mem /c" (without the quotation marks) at the MS-DOS command prompt. The memory used by the mouse driver is reported correctly, as in the following sample report:

   
         Name        Total     =        Conventional   +  Upper Memory
         -------------------------------------------------------------
         MOUSE       25,328 (25K)       272 (0K)          25,056 (24K) 




3. Remove the DOS=UMB line from the CONFIG.SYS file and then restart your computer.



4. Type "mem /c" (without the quotation marks) at the MS-DOS command prompt. The memory used by the mouse driver is reported incorrectly, as in the following sample report:

   
         Name        Total     =        Conventional   +  Upper Memory
         -------------------------------------------------------------
         MOUSE       272 (0K)           272 (0K)          0 (0K) 

Additional query words: 5.x 6.00 6.20 6.21 6.22 9.x 10.00

Keywords : msdos
Version : 5.x 6.00 6.20 6.21 6.22 9.x 10.0
Platform : MS-DOS
Issue type :