Microsoft KB Archive/79032

= Basic OPEN ACCESS and File SHARE Unsupported in MS-DOS 1.x/2.x =

Article ID: 79032

Article Last Modified on 11/21/2006



This article was previously published under Q79032



SUMMARY
In Microsoft Basic and QuickBasic, you cannot perform file sharing with the ACCESS keyword of the OPEN statement under versions of MS-DOS earlier than 3.0. The result is an error 73, &quot;Advanced Feature Unavailable.&quot;

This information applies to Microsoft GW-Basic versions 3.2, 3.22, and 3.23; Microsoft QuickBasic versions 3.0, 4.0, 4.0b, and 4.5; Microsoft Basic Compiler versions 6.0 and 6.0b; and Microsoft Basic Professional Development System (PDS) versions 7.0 and 7.1 for MS-DOS.



MORE INFORMATION
The following is a typical OPEN statement and its features (found in the language reference manual for each version of Basic): OPEN file [FOR mode] [ACCESS access] [lock] AS [#]filenumber [LEN=reclen] In versions of MS-DOS earlier than 3.0, the ACCESS feature is not available because the MS-DOS interrupt 21 hex with function 3D hex (Open File) does not support file sharing under versions of MS-DOS earlier than 3.0. This is a limitation of the MS-DOS versions 1.x and 2.x.

If you use the ACCESS keyword in a Basic OPEN statement under MS-DOS version 3.0 or later, you must run the SHARE.EXE program (or the network startup must run it) before you can perform any file locking operation.

Under MS-DOS version 4.01, SHARE.EXE will be loaded automatically if there are hard drive partitions greater than 32K.

Note that Microsoft designed Basic PDS 7.0 and 7.1 for MS-DOS version 3.0 or later, as stated on the product box.

Additional query words: QuickBas BasicCom 3.00 4.00 4.00b 4.50 6.00 6.00b 7.00 7.10

Keywords: KB79032

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