Up to 48 Buffers Load in HMA with MS-DOS 5.0 (76186)

The information in this article applies to:
    Microsoft MS-DOS operating system 5.0

This article was previously published under Q76186


When you load MS-DOS high, it is loaded into the high memory area (HMA), the first 64K block of extended memory at the A20 address line. If you have buffers set to 48 or fewer in the CONFIG.SYS file, most of the time the buffers are also loaded into the HMA.

If all the buffers do not fit in the HMA because of other memory use (line code pages), all the buffers are loaded in conventional memory.


To load MS-DOS and buffers into the HMA, you must have an 80286, 80386, or 80486 microprocessor and extended memory. Your CONFIG.SYS file should include the following statements:


The buffers= statement in the above example is set to the maximum number of buffers that can usually be loaded into the HMA. Buffers= can be set to any value between 1 and 99.

The amount of conventional memory being used for the disk buffers can be determined using the MEM /P[rogram] or MEM /D[ebug] commands. If the size value for buffers is 200 hexadecimal, the buffers are loaded into the HMA.

Note: One buffer is always loaded into conventional memory; therefore, the number of buffers actually loaded into the HMA is one fewer than the number of buffers specified.

For more information loading buffers in the HMA, query on the following words in the Microsoft Knowledge Base:


(c) Microsoft Corporation 2000, All Rights Reserved. Contributions by Kevin Zollman, Microsoft Corporation.

Modification Type: Major Last Reviewed: 11/6/2002
Keywords: KB76186