Microsoft KB Archive/99008

= MS-DOS 6 MEM Command Reports 384K for Adapter RAM/ROM =

Article ID: 99008

Article Last Modified on 11/21/1999

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APPLIES TO


 * Microsoft MS-DOS 6.0 Standard Edition

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This article was previously published under Q99008



SUMMARY
The MS-DOS 6 MEM command may display an incorrect value for Adapter RAM/ROM. On many machines, MEM displays a table similar to the following:   Memory Type        Total =  Used  +  Free --

Conventional       640K     126K     515K Upper              139K     111K      28K Adapter RAM/ROM    384K     384K       0K Extended (XMS)    7029K    2781K    4248K --

Total memory      8192K    3401K    4791K It is not possible to have 384K Adapter RAM/ROM and a value greater than zero for upper memory.



Adapter RAM/ROM
The value specified by Adapter RAM/ROM is calculated as follows:

1 MB (1024K) minus conventional memory, minus upper memory

block (UMB) space

Therefore, Adapter RAM/ROM is the sum of the following:


 * Excluded UMB space
 * Memory used by BIOS and adapter cards
 * Expanded memory services (EMS) page frame(s)

However, on machines in which the amount of reported extended memory is below the 1 MB boundary (384K or less), MEM increases the value reported for Adapter RAM/ROM so that the total memory on the system is a multiple of 1 MB.

NOTE: The amount of extended memory reported is correct.

Definitions
The upper memory area (UMA) is a range of addresses between 640K and 1 MB (1024K). This area is also commonly called the reserved address space.

Upper memory blocks (UMBs) are areas in the UMA that EMM386.EXE has reserved for loading device drivers and terminate-and-stay-resident (TSR) programs high.

Additional query words: 6.00 XMS

Keywords: KB99008

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