DOCUMENT:Q73843  17-DEC-2000  [msdos]
TITLE   :Files and Buffers Memory Usage
PRODUCT :Microsoft Disk Operating System
PROD/VER:MS-DOS:5.x,6.0,6.2,6.21,6.22
OPER/SYS:
KEYWORDS:

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The information in this article applies to:

 - Microsoft MS-DOS operating system versions 5.0, 5.0a, 6.0, 6.2, 6.21, 6.22 
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SUMMARY
=======

The following article explains MS-DOS version 5.x and later files and buffers
memory usage.

MORE INFORMATION
================

Buffers
-------

The version 5.0 "Microsoft MS-DOS User's Guide and Reference" states on page 376
that buffers are automatically loaded into the high memory area (HMA) when the
DOS=HIGH statement is used in the CONFIG.SYS file.

The required 512 bytes (200h) is always loaded in conventional memory. This
number remains constant regardless of the number of buffers specified.

If DOS=LOW, or no DOS= line exists in the CONFIG.SYS file, buffers are allocated
in conventional memory. Each buffer uses approximately 532 bytes of memory.

Files
-----

The memory consumed by the FILES= statement in the CONFIG.SYS file is always
allocated in conventional memory, regardless of the DOS= statement in the
CONFIG.SYS file.

There is no constant number for the amount of memory used by each allocated file
in the FILES= statement. As the number of files allocated increases, the amount
of memory required for each file increases also. A chart of commonly used
amounts follows:

   # Files in       Bytes used         Bytes used
   CONFIG.SYS       in Decimal           in Hex
   ----------------------------------------------

     Default            192                 C0
        10              496                130
        15              608                260
        20              896                380
        25             1200                4B0
        30             1488                5D0
        35             1776                6F0
        40             2080                820
        45             2368                940
        50             2672                A70
        55             2960                B90
        60             3260                CC0
        65             3552                DE0
        70             3856                F10
        75             4144               1030

Additional query words: 6.22 5.00 5.00a 6.00 6.20

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Keywords          :  
Technology        : kbMSDOSSearch kbMSDOS621 kbMSDOS622 kbMSDOS620 kbMSDOS600 kbMSDOS500 kbMSDOS500a
Version           : MS-DOS:5.x,6.0,6.2,6.21,6.22

=============================================================================

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