Focus software
Albert D. Edgar, S.C. Lee · 1979
FOCUS is a number system and supporting soft ware especially useful for microcomputer control and other signal processing applications. FOCUS has the wide ranging character of floating-point numbers with a uniformity of state distributions that give FOCUS approximately a fourfold accuracy advantage over an equal length floating-point system. FOCUS computations are typically five times faster than equal word length single precision fixed-point or integer arithmetic for a mixture of operations, comparable with hardware arithmetic in speed for many applications. Algorithms for 8-bit and two versions of 16-bit FOCUS are included. With FOCUS, an 8080A can perform the equivalent of over 20,000 18-bit floating-point additions, subtractions, multiplications, and divisions in one second, and store the results in 16-bit words. FOCUS is more than a theory, it is a completed system providing near hardware speed, 18-bit accuracy, floating-point range, and 8-bit cost.