Floating Point Formats Used by Microsoft BASIC Products

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This article was previously published under Q45166

SUMMARY

The floating point formats used by Microsoft BASIC products depend on which BASIC product and version number are being used, as shown below.

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MORE INFORMATION

The following products support decimal math, which is very accurate (such as for dollars and cents calculations), but slow:

Microsoft Business BASIC Compiler versions 1.00 and 1.10 for MS-DOS
Microsoft BASIC (d) Interpreter versions 2.00, 2.10, and 3.00 for the Apple Macintosh
Microsoft QuickBASIC (d) version 1.00 for the Apple Macintosh
Microsoft BASIC Compiler version 1.00 for the Apple Macintosh (compiled with the D option, "Compile for Decimal Math")

The following products support the Microsoft Binary Format (MBF):

Microsoft BASIC Compiler versions 5.35 and 5.36 for MS-DOS
Microsoft BASIC Interpreter version 5.28 for MS-DOS
Microsoft QuickBASIC versions 1.00, 1.01, 1.02, 2.00, and 2.01 for the IBM PC and compatibles
Noncoprocessor version (QB.EXE) of Microsoft QuickBASIC version 3.00 for the IBM PC and compatibles
Microsoft GW-BASIC Interpreter versions 2.00, 2.10, 3.20, 3.22, and 3.23 for MS-DOS
Microsoft BASIC Interpreter version 5.21 for CP/M-80
Microsoft BASIC Compiler version 5.30 for CP/M-80
All versions of the IBM BASICA Interpreter
IBM BASIC Compiler through version 2.00

The following products support the IEEE floating point format:

Microsoft QuickBASIC versions 4.00, 4.00b, and 4.50 for the IBM PC and compatibles.
The coprocessor version of Microsoft QuickBASIC 3.00 (QB87.EXE) for the IBM PC and compatibles.
Microsoft BASIC Compiler versions 6.00 and 6.00b for MS-DOS and MS OS/2. This product also supports the Alternate Math package (BC /FPa), which follows the IEEE format but does not emulate or use a coprocessor, and is faster than the Emulation Math package (BC /FPi, the default) on machines without a coprocessor.
Microsoft BASIC PDS versions 7.00 and 7.10 for MS-DOS and MS OS/2. This product also supports the Alternate Math package (BC /FPa), which follows the IEEE format but does not emulate or use a coprocessor, and is faster than the Emulation Math package (BC /FPi, the default) on machines without a coprocessor.
Microsoft BASIC (b) Interpreter versions 1.00, 1.01, 2.00, 2.10, and 3.00 for the Apple Macintosh.
Microsoft BASIC Compiler version 1.00 for the Apple Macintosh (compiled WITHOUT the compiler's D option).
Microsoft QuickBASIC (b) for the Apple Macintosh version 1.00.

The following product supports the CURRENCY Data type, which stores decimal numbers exactly and accurate to four decimal places (ideal for business applications using dollars and cents):

Microsoft BASIC Professional Development System (PDS) versions 7.00 and 7.10 for MS-DOS and MS OS/2

(See the table below for a quick reference to floating-point support by BASIC products.)

For more information concerning IEEE format versus Microsoft Binary Format, please see Pages 131-134 in the "Microsoft Macro Assembler 5.1: Programmer's Guide," or see the "IEEE and Rounding" application note, which can be obtained by calling Microsoft Technical Support. More information is also available in this database by querying on the following keywords:

floating point and format

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Table: Floating Point Support, by BASIC Product and Version

    Product and Version     |  Decimal  |  Microsoft |  IEEE | CURRENCY
                            |   Math    |   Binary   |       |   Data
----------------------------|-----------|------------|-------|----------
MS BASIC PDS, MS-DOS and    |           |            |       |
MS OS /2:  7.00, 7.10       |           |            |   X   |    X
                            |           |            |       |

MS BASIC Compiler, MS-DOS:  |           |            |       |

    6.00, 6.00b             |           |            |   X   |
    5.35, 5.36              |           |      X     |       |
                            |           |            |       |

MS BASIC Interpreter MS-DOS:|           |            |       |

    5.28                    |           |      X     |       |
                            |           |            |       |

MS QuickBASIC for IBM PC:   |           |            |       |

    1.00, 1.01, 1.02        |           |      X     |       |
    2.00, 2.01              |           |      X     |       |
    3.00 (QB.EXE)           |           |      X     |       |
    3.00 (QB87.EXE)         |           |            |   X   |
    4.00, 4.00b, 4.50       |           |            |   X   |
                            |           |            |       |

MS GW-BASIC for MS-DOS:     |           |            |       |

    2.00, 2.10 (OEM only),  |           |      X     |       |
    3.20, 3.22, 3.23        |           |      X     |       |
                            |           |            |       |

MS BASIC Interpreter CP/M-80|           |            |       |

    5.21                    |           |      X     |       |
                            |           |            |       |

MS BASIC Compiler, CP/M-80: |           |            |       |

    5.30, 5.35              |           |      X     |       |
                            |           |            |       |

The IBM BASIC Compiler      |           |            |       |

    for MS-DOS:             |           |            |       |
    2.00 (and earlier)      |           |      X     |       |
                            |           |            |       |

IBM BASICA Interpreter      |           |            |       |

    for MS-DOS:             |           |            |       |
    All versions            |           |      X     |       |
                            |           |            |       |

Microsoft BASIC Interpreter |           |            |       |

    for Macintosh:          |           |            |       |
    1.00, 1.01,             |           |            |   X   |
    2.00, 2.10,             |     X     |            |   X   |
    3.00                    |     X     |            |   X   |
                            |           |            |       |

Microsoft BASIC Compiler    |           |            |       |

    for Macintosh:          |           |            |       |
    1.00                    |     X     |            |   X   |
                            |           |            |       |

Microsoft QuickBASIC for    |           |            |       |

    Macintosh:              |           |            |       |
    1.00                    |     X     |            |   X   |
                            |           |            |       |

Microsoft Business BASIC    |           |            |       |

    MS-DOS:                 |           |            |       |
    1.00, 1.10              |     X     |            |       |

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KB45166

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Retired KB Content Disclaimer

This article was written about products for which Microsoft no longer offers support. Therefore, this article is offered "as is" and will no longer be updated.

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