ADT: Description of the Visual Basic Compatibility Layer (114834)

SUMMARY

Microsoft Visual Basic version 3.0 has the ability to communicate with Microsoft Access databases. However, the modules supplied with Visual Basic version 3.0 can communicate only with Microsoft Access version 1.x-created databases.

For Visual Basic to communicate with Microsoft Access version 2.0-created databases, a group of files referred to as the Visual Basic Compatibility Layer (VBCL) is required. Some of these files are new, while others replace or modify existing files.

You can obtain the VBCL from the following sources:

The Microsoft Access Developer's Toolkit (ADT) version 2.0
The Microsoft Office Developer's Kit (ODK) version 1.0
The following file is available for download from the Microsoft Download Center:
Download Comlyr.exe now
The Comlyr.exe file contains the VBCL.

For additional information about how to download Microsoft Support files, click the following article number to view the article in the Microsoft Knowledge Base:
119591 How to Obtain Microsoft Support Files from Online Services
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MORE INFORMATION

The Microsoft Access Developer's Toolkit version 2.0 supplies the VBCL and the Microsoft Jet database engine version 2.0, along with numerous other database development tools.

The Microsoft Office Developer's Kit version 1.0 contains the VBCL, along with other tools to aid in the development of Microsoft Office applications, but does not include version 2.0 of the Microsoft Jet database engine. Version 1.1 of the Microsoft Jet database engine is included.

To obtain pre-sales information about new or updated Microsoft products, call the Microsoft Sales Information Center at (800) 426-9400. If you are outside the United States, contact the Microsoft subsidiary for your area. To locate your subsidiary, please see the Microsoft World Wide Offices Web Site at:

http://www.microsoft.com/worldwide/

VBCL Files

NOTE: The file locations listed below assume default installation directories.

File          Description                            Location
----------------------------------------------------------------------
VBDB300.DLL   VB to Jet DB engine 1.1 Interface DLL  C:\WINDOWS\SYSTEM
PDCTJET.DLL   Run-time DLL for Crystal Reports       C:\WINDOWS\SYSTEM
PDIRJET.DLL   Run-time DLL for Crystal Reports       C:\WINDOWS\SYSTEM
PDBJET.DLL    Run-time DLL for Crystal Reports       C:\WINDOWS\SYSTEM
CRW.EXE       Crystal Report Designer application    C:\VB\REPORT
VB.INI        Visual Basic initialization file       C:\WINDOWS
SETUPWIZ.INI  Setup Wizard initialization file       C:\WINDOWS
KBINTEROP

Files Needed to Upgrade Visual Basic Version 3.0:

File          Description                            Location
----------------------------------------------------------------------
MSAJT200.DLL  Version 2.0 Jet database engine        C:\WINDOWS\SYSTEM
MSAJT112.DLL  Jet DB engine 2.0/VBCL                 C:\WINDOWS\SYSTEM
VBDB300.DLL   VB to Jet DB engine Support DLL        C:\WINDOWS\SYSTEM
BTRV200.DLL   Btrieve ISAM driver library            C:\WINDOWS\SYSTEM
PDX200.DLL    Paradox ISAM driver library            C:\WINDOWS\SYSTEM
XBS200.DLL    Microsoft FoxPro ISAM driver library   C:\WINDOWS\SYSTEM
CRWACC20.EXE  Program that modifies Crystal Reports  C:\VB
              files to work with Microsoft Access
              version 2.0 databases
ACC2COMP.TXT  Readme file for VBCL                   C:\VB

Note that the Microsoft Access 2.0 Service Pack contains a new BTRV200.DLL file that corrects three common issues when using Btrieve data with Microsoft Access:

Performance improved in queries based on multisegmented indexes and indexes based on Type 8 - COBOL Numeric datatype fields No longer returns incorrect results when a query uses an index based on Type 8 - COBOL Numeric dataype fields No longer returns "Unexpected Error from External Database Driver [7]" error message when using Btrieve 6.x NLM
No longer returns incorrect results when a query uses an index based on Type 8 - COBOL Numeric dataype fields No longer returns "Unexpected Error from External Database Driver [7]" error message when using Btrieve 6.x NLM
No longer returns "Unexpected Error from External Database Driver [7]" error message when using Btrieve 6.x NLM