DOSKEY Maximum Buffer Size is 61900 Bytes (87284)
The information in this article applies to:
• Microsoft MS-DOS operating system 5.0
• Microsoft MS-DOS operating system 5.0a
• Microsoft MS-DOS operating system 6.0
This article was previously published under Q87284
SYMPTOMS
Specifying a buffer size larger than 61900 for DOSKEY causes your
computer to stop responding (hang).
CAUSE
The maximum size of the DOSKEY command history and macro buffer is
equal to 64K minus the size of the DOSKEY program itself. This works
out to approximately 61900 bytes. Due to an error in the DOSKEY
program, specifying a buffer size larger than this will cause your
computer to hang. To avoid this problem, specify a buffer of 61900
bytes or less.
STATUS
Microsoft has confirmed this to be a problem in MS-DOS versions 5.0,
5.00a, and 6.00. This problem was corrected in later versions.
MORE INFORMATION
Because DOSKEY is a .COM program, it is limited to 64K of memory for
both its code and data. For this reason, the maximum command history
and macro buffer size is equal to 64K minus the DOSKEY code, or
approximately 61900 bytes.
If you specify a buffer size larger than can fit within the DOSKEY 64K
memory segment, DOSKEY will detect it and automatically truncate the
buffer. While DOSKEY correctly limits the size of the buffer, an error
in the code used when DOSKEY terminates and stays resident causes
DOSKEY to miscalculate the amount of memory to free on termination.
As a result, the memory where DOSKEY is loaded is marked as unused.
The next program that runs will be placed where DOSKEY is already
located, which causes the computer to hang.
Reference(s):
"Microsoft MS-DOS User's Guide and Reference," versions 5.0 and 5.0a
| Modification Type: |
Major |
Last Reviewed: |
10/12/2003 |
| Keywords: |
KB87284 |
|