Mem

The MEM command is used to display a table showing how memory (RAM) is currently allocated.

Syntax:

MEM [/Switches]

None Displays the status of the computer's used and free memory

/A Adds an extra line about available space in the High Memory Area.

/C Lists the programs that are currently loaded into memory and shows how much conventional and upper memory each program is using.

/D Lists the programs and internal drivers that are currently loaded into memory.

/F Lists the free areas of conventional and upper memory.

/M progname Shows how the program (progname) is currently using memory.

/P Pauses after each screenful of information.

/H Brief help (same as /?)

Notes:

The status of expanded memory is only included if it conforms to version 4.0 of the Lotus/Intel/Microsoft Expanded Memory Specification (LIM EMS).
The status of the upper memory area is only displayed if a UMB provider such as EMM386 is installed and the command DOS=UMB is included in the "Config.sys" file.

Examples:

C:\WINDOWS>MEM Memory Type Total Used Free ---------------- -------- -------- -------- Conventional 636K 70K 566K Upper 195K 195K 0K Reserved 0K 0K 0K Extended (XMS) 15,165K 169K 14,996K ---------------- -------- -------- -------- Total memory 15,996K 434K 15,562K Total under 1 MB 831K 264K 566K Largest executable program size 566K (579,888 bytes) Largest free upper memory block 0K (0 bytes) MS-DOS is resident in the high memory area. C:\WINDOWS>_

C:\WINDOWS>MEM /A Memory Type Total Used Free ---------------- -------- -------- -------- Conventional 636K 70K 566K Upper 195K 195K 0K Reserved 0K 0K 0K Extended (XMS) 15,165K 169K 14,996K ---------------- -------- -------- -------- Total memory 15,996K 434K 15,562K Total under 1 MB 831K 264K 566K Largest executable program size 566K (579,888 bytes) Largest free upper memory block 0K (0 bytes) Available space in High Memory Area 0K (368 bytes) MS-DOS is resident in the high memory area. C:\WINDOWS>_

C:\WINDOWS>MEM /C Modules using memory below 1 MB: Name Total Conventional Upper Memory -------- ---------------- ---------------- ---------------- SYSTEM 38,400 (38K) 13,040 (13K) 25,360 (25K) HIMEM 1,168 (1K) 1,168 (1K) 0 (0K) EMM386 4,320 (4K) 4,320 (4K) 0 (0K) .... ... ... ... ... ... ... SETVER 832 (1K) 0 (0K) 832 (1K) MSCDEX 32,176 (31K) 0 (0K) 32,176 (31K) Free 579,904 (566K) 579,904 (566K) 0 (0K) Memory Summary: Type of Memory Total Used Free ---------------- ----------- ----------- ----------- Conventional 651,264 71,360 579,904 Upper 199,312 199,312 0 Reserved 0 0 0 Extended (XMS) 15,529,328 173,424 15,355,904 ---------------- ----------- ----------- ----------- Total memory 16,379,904 444,096 15,935,808 Total under 1 MB 850,576 270,672 579,904 Largest executable program size 579,888 (566K) Largest free upper memory block 0 (0K) MS-DOS is resident in the high memory area. C:\WINDOWS>_

"Reserved" is the memory located on add-on boards such as video adapter boards.
"Largest executable program size" is the largest contiguous block of conventional memory available for a program.
"Largest free upper memory block" is the largest area of upper memory available for a program.
"MS-Dos is resident in the high memory area" indicates that MS-Dos is running in the first 64K of extended memory rather than in conventional memory.

C:\WINDOWS>MEM /D Conventional Memory Detail: Segment Total Name Type ------- ---------------- ----------- -------- 00000 1,024 (1K) Interrupt Vector 00040 256 (0K) ROM Communication Area 00050 512 (1K) DOS Communication Area 00070 1,424 (1K) IO System Data CON System Device Driver AUX System Device Driver .... ... ... .... ...... 0116B 90,400 (88K) MEM Program 0277D 489,504 (478K) MSDOS -- Free -- 09EFF 2,992 (3K) IO System Data 09FBA 80 (0K) -------- Data Upper Memory Detail: Segment Region Total Name Type ------- ------ ---------------- ----------- -------- 0B15B 1 2,608 (3K) vmm32 Data 0C801 2 26,896 (26K) IO System Data 26,864 (26K) CTSOUND0 Installed Device=CTSB16 ... .. ... ... .... ..... 0E900 2 32,176 (31K) MSCDEX Program 0F0DB 2 29,264 (29K) vmm32 Data Memory Summary: Type of Memory Total Used Free ---------------- ----------- ----------- ----------- Conventional 651,264 71,360 579,904 Upper 199,312 199,312 0 Reserved 0 0 0 Extended (XMS) 15,529,328 173,424 15,355,904 ---------------- ----------- ----------- ----------- Total memory 16,379,904 444,096 15,935,808 Total under 1 MB 850,576 270,672 579,904 Memory accessible using Int 15h 0 (0K) Largest executable program size 579,888 (566K) Largest free upper memory block 0 (0K) MS-DOS is resident in the high memory area. XMS version 3.00; driver version 3.95 C:\WINDOWS>_

C:\WINDOWS>MEM /F Free Conventional Memory: Segment Total ------- ----------------- 01159 288 (0K) 0116B 90,400 (88K) 0277D 489,504 (478K) Total Free: 580,192 (567K) Free Upper Memory: Region Largest Free Total Free Total Size ------ -------------- -------------- -------------- 1 0 (0K) 0 (0K) 2,608 (3K) 2 0 (0K) 0 (0K) 196,704 (192K) C:\WINDOWS>_

To find out what memory the 'vmm32' module has been allocated:

C:\WINDOWS>MEM /M vmm32 VMM32 is using the following memory: Segment Region Total Type ------- ------ ---------------- -------- 00914 48 (0K) Data 00917 3,728 (4K) Program 0B15B 1 2,608 (3K) Data 0E8ED 2 304 (0K) Data 0F0DB 2 29,264 (29K) Data ---------------- Total Size: 35,952 (35K) C:\WINDOWS>_

File Details

File Name	Default Location	Dos Ver.	Win Ver.	Size	Date	Source
Mem.exe	c:\windows\command	7.0	Win95	32 082	11/07/95	win95_08.cab
		7.1	Win95 (OSR2.x)	32 146¹	24/08/96	win95_14.cab
			Win98	32 146¹	11/05/98	win98_41.cab
			Win98 SE	32 146¹	23/04/99	win98_46.cab

Superscripts denote which same size files, if any, are identical (using FC).

Thanks to Gerard Schildberger for pointing out the /H switch
This page last revised: August 28, 2000.