Microsoft KB Archive/51811

Problem When FASTOPEN.EXE Is Used with dBASE III PLUS PSS ID Number: Q51811 Article last modified on 07-14-1993 PSS database name: O_MSDOS

4.00 4.01

MS-DOS

Summary:

If you use dBASE III PLUS, you may experience a problem in the fastseek portion of FASTOPEN included with MS-DOS versions 4.0 and 4.01. This problem occurs only when the second parameter of the FASTOPEN arguments is included, such as in the following statement:

FASTOPEN C:=(50,50)

The problem arises when an open file is truncated at some point and then extended again. The problem occurs in dBASE when the ZAP command is used, and then records are added to the file. For more information on how to reproduce this problem, see the information provided below.

Microsoft has confirmed this to be a problem in MS-DOS versions 4.00 and 4.01. This problem does not occur in later versions of MS-DOS.

The new FASTOPEN.EXE file that contains a correction for this problem is available. The corrected version of FASTOPEN.EXE is contained in a file named FASTOPEN and can be found in the Software/Data Library by searching on the word FASTOPEN, the Q number of this article, or S12494. FASTOPEN was archived using the PKware file-compression utility.

FASTOPEN.EXE is also contained in an application note entitled “MS-DOS 4.0x Patch Disk” (PD0255). Application notes can be obtained by calling Microsoft Product Support Services.

We recommend that you do not use this file with other versions of MS-DOS, nor should you use it with original equipment manufacturer (OEM) versions of MS-DOS version 4.01. If you have an OEM version of MS-DOS version 4.01, please contact your OEM regarding this problem.

More Information:

To easily reproduce this problem, set up FASTOPEN with extents processing, and then run dBASE III PLUS with the necessary commands, which are listed below:

FASTOPEN C:=(,2)

(dBASE III PLUS Commands)

. USE FILE1 . COPY TO FILE2 . ZAP . APPEND FROM FILE2 Note: FILE1 is a file larger than 1 cluster. The results vary depending on the exact circumstances. In some cases, the data in the file is corrupted. In other cases, a “Sector not found” critical error is generated. It is also possible that other data on the disk, or perhaps the entire disk itself, is seriously corrupted, so performing this test is not recommended.

Additional reference words: 4.00 4.01 noupd

Copyright Microsoft Corporation 1993.