Some TWAIN drivers will work smoothly when invoked from a Microsoft-compiled application, but will throw fatal run-time errors when accessed from an application written in Borland Delphi or C++ Builder.

This notice applies to developers working in Borland Delphi and C++ Builder, and to all TWAIN DataSource developers.

Summary: Floating point computations can generate exceptions such as overflow, underflow, divide-by-zero. In Microsoft Visual C/C++ applications, these exceptions are suppressed by default. Delphi and C++ Builder enable exceptions for overflow and divide-by-zero by default. Some TWAIN drivers (Canon Network ScanGear 1.4, 1.5, Leica DFC 280) generate these floating-point exceptions during normal operation! As a result those TWAIN drivers will work smoothly when invoked from a Microsoft-compiled application, but will throw fatal run-time errors when accessed from an application written in Borland Delphi or C++ Builder.

Delphi and C++ Builder Application Developers: This Borland page explains how to suppress these exceptions in your applications, in effect simulating the Microsoft run-time configuration for floating-point. If your application makes sophisticated use of floating-point, you will need to study this issue carefully.

TWAIN DataSource Developers: Test your DataSources with at least one application written in Delphi or C++ Builder! Or, in your DS main entry, save the current floating-point control word, and disable floating-point exceptions. Before returning, clear any pending exceptions and then restore the floating-point control word. Contact support@dosadi.com if you want help figuring out how to do this.