Microsoft KB Archive/11936

= List of Basics Using MBF versus IEEE Floating-Point Format =

Article ID: 11936

Article Last Modified on 11/21/2006



This article was previously published under Q11936



SUMMARY
This article lists which Basic versions (for MS-DOS) use Microsoft Binary Format (MBF) and which versions use IEEE format for storing single- and double-precision floating-point numbers.



MORE INFORMATION
Single- and double-precision real numbers are stored in the Microsoft Binary Format (MBF) in the following languages:


 * 1) QuickBasic versions 1.00, 1.01, 1.02, 2.00, 2.01, and the non-coprocessor QB.EXE version 3.00, for MS-DOS
 * 2) IBM and Compaq BasicA Interpreters (BasicA.COM) for MS-DOS
 * 3) GW-Basic Interpreter versions 3.20, 3.22, and 3.23 (GWBasic.EXE) for MS-DOS
 * 4) Microsoft Basic Interpreter version 5.28 for MS-DOS
 * 5) Microsoft Basic Compiler versions 5.35 and 5.36 for MS-DOS

QuickBasic versions 4.00, 4.00b, and 4.50 (QB.EXE, BC.EXE) and the coprocessor version of QuickBasic version 3.00 (QB87.EXE) use IEEE floating-point format for single- and double-precision real numbers.

Note that Microsoft Business Basic Compiler versions 1.00 and 1.10 use a different floating-point format called Decimal Math. Decimal Math is very slow but has no rounding or representation errors because numbers are stored in their exact decimal form, instead of in an approximate binary form. (Sales of Business Basic were discontinued.)

In QuickBasic version 3.00, the coprocessor version of QuickBasic uses IEEE format numbers. Conversion routines are provided in version 3.00 to convert between the MBF used in the non-coprocessor version (QB.EXE) and the IEEE floating-point format used in the coprocessor version (QB87.EXE).

QuickBasic versions 4.00, 4.00b, and 4.50; Microsoft Basic Compiler versions 6.00 and 6.00b; and Microsoft Basic Professional Development System (PDS) versions 7.00 and 7.10 only use IEEE format numbers, but conversion routines and a compiler switch are provided to convert between MBF and IEEE format. This conversion is necessary if you want to retrieve floating-point numbers from random access files that were created using MBF.

