Q73843: Files and Buffers Memory Usage
Article: Q73843
Product(s): Microsoft Disk Operating System
Version(s): MS-DOS:5.x,6.0,6.2,6.21,6.22
Operating System(s):
Keyword(s):
Last Modified: 17-DEC-2000
-------------------------------------------------------------------------------
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
-------------------------------------------------------------------------------
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
======================================================================
Keywords :
Technology : kbMSDOSSearch kbMSDOS621 kbMSDOS622 kbMSDOS620 kbMSDOS600 kbMSDOS500 kbMSDOS500a
Version : MS-DOS:5.x,6.0,6.2,6.21,6.22
=============================================================================
THE INFORMATION PROVIDED IN THE MICROSOFT KNOWLEDGE BASE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND. MICROSOFT DISCLAIMS ALL WARRANTIES, EITHER EXPRESS OR IMPLIED, INCLUDING THE WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL MICROSOFT CORPORATION OR ITS SUPPLIERS BE LIABLE FOR ANY DAMAGES WHATSOEVER INCLUDING DIRECT, INDIRECT, INCIDENTAL, CONSEQUENTIAL, LOSS OF BUSINESS PROFITS OR SPECIAL DAMAGES, EVEN IF MICROSOFT CORPORATION OR ITS SUPPLIERS HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. SOME STATES DO NOT ALLOW THE EXCLUSION OR LIMITATION OF LIABILITY FOR CONSEQUENTIAL OR INCIDENTAL DAMAGES SO THE FOREGOING LIMITATION MAY NOT APPLY.
Copyright Microsoft Corporation 1986-2002.