Accession Number : AD0651201

Title :   FLOATING-POINT NUMBER REPRESENTATIONS: BASE CHOICE VERSUS EXPONENT RANGE.

Descriptive Note : Technical rept.,

Corporate Author : STANFORD UNIV CALIF DEPT OF COMPUTER SCIENCE

Personal Author(s) : Richman,Paul

Report Date : 28 APR 1967

Pagination or Media Count : 38

Abstract : A digital computer whose memory words are composed of r-state devices is considered. The choice of the base, beta, for the internal floating-point numbers on such a computer is discussed. Larger values of beta necessitate the use of more r-state devices for the mantissa, in order to preserve some 'minimum accuracy,' leaving fewer r-state devices for the exponent of beta. As beta increases, the exponent range may increase for a short period, but it must ultimately decrease to zero. Of course, this behavior depends on what definition of accuracy is used. This behavior is analyzed for a recently proposed definition of accuracy which specifies when it is to be said that the set of q-digit base beta floating-point numbers is accurate to p-digits base t. The only case of practical importance today is t = 10 and r = 2; and in this case beta = 2 is always best. However, the analysis is done to cover all cases. (Author)

Descriptors :   (*DIGITAL COMPUTERS, *MEMORY DEVICES), ACCURACY, NUMBERS, SET THEORY, DATA STORAGE SYSTEMS

Subject Categories : Computer Hardware

Distribution Statement : APPROVED FOR PUBLIC RELEASE