Q11936: List of BASICs Using MBF versus IEEE Floating-Point Format

Article: Q11936
Product(s): See article
Version(s): 1.00 1.01 1.02 2.00 2.01 3.00 4.00 4.00b 4.50
Operating System(s): MS-DOS
Keyword(s): ENDUSER | B_BasicCom | mspl13_basic
Last Modified: 14-FEB-1991

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.

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.

References:

For additional articles that discuss MBF and IEEE, search for the
following words:

   floating and point and format and QuickBASIC

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