Mem

Index

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.
/HBrief help (same as /?)

Notes:

  1. 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).
  2. 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 NameDefault LocationDos Ver.Win Ver.SizeDateSource
Mem.exec:\windows\command 7.0Win95 32 08211/07/95win95_08.cab
7.1Win95 (OSR2.x) 32 146124/08/96win95_14.cab
Win98 32 146111/05/98win98_41.cab
Win98 SE 32 146123/04/99win98_46.cab

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


Thanks to Gerard Schildberger for pointing out the /H switch
If you should have any comments or suggestions,
please contact: Bob Watson
.
This page last revised:
August 28, 2000.