No Data Type for 80-Bit Precision IEEE Real Numbers in Basic (35248)


The information in this article applies to:

  • Microsoft QuickBASIC 3.0
  • Microsoft QuickBASIC 4.0
  • Microsoft QuickBASIC 4.0b
  • Microsoft QuickBASIC 4.5
  • Microsoft BASIC Compiler for MS-DOS and OS/2 6.0
  • Microsoft BASIC Compiler for MS-DOS and OS/2 6.0b
  • Microsoft Basic Professional Development System (PDS) for MS-DOS and MS OS/2 7.0
This article was previously published under Q35248

SUMMARY

QuickBasic's implementation of the ANSI/IEEE Standard 754-1985 for binary floating-point arithmetic includes two types of real numbers:

Single-precision numbers, which use 32 bits (4 bytes)
Double-precision numbers, which use 64 bits (8 bytes)

The ANSI/IEEE standard also describes an 80-bit (10-byte) floating-point format called Double Extended. QuickBasic's intermediate calculations are performed in the 80-bit format for greater accuracy, but the results are stored in single- or double-precision variables. There is no data type in QuickBasic associated with the 80-bit format.

This article applies to the following products, which use IEEE binary floating-point arithmetic:

  1. Microsoft QuickBasic Versions 3.00 (QB87.EXE only), 4.00, 4.00b, and 4.50 for the IBM PC
  2. Microsoft Basic Compiler Versions 6.00 and 6.00b for MS OS/2 and MS-DOS
  3. Microsoft Basic PDS Version 7.00 for MS-DOS and MS OS/2

MORE INFORMATION

ANSI is an acronym for the American National Standards Institute. IEEE is an acronym for the Institute of Electrical and Electronics Engineers, Inc., which can be reached at the following address:

IEEE
345 East 47th Street
New York, NY 10017 USA

Modification Type:MinorLast Reviewed:1/9/2003
Keywords:KB35248
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