Byte using six-bit and nine-bit bytes were common into the 1960s. These machines most commonly had memory words of 12, 24, 36, 48 or 60 bits, corresponding to two, four, six, eight or 10 six-bit bytes. In this era, bytes in the instruction stream were often referred to as "syllables", before the term byte became common. The modern "de-facto" standard of eight bits, as documented in ISO/IEC 2382-1:1993, is a convenient power of two permitting the values 0 through 255 for one byte (2 in power of 8 = 256, where zero signifies number as well). The international standard IEC 80000-13
Stochastic computing can take the logical AND of the two streams. The probability of a one in the output stream is formula_5. By observing enough output bits and measuring the frequency of ones, it is possible to estimate formula_5 to arbitrary accuracy. The operation above converts a fairly complicated computation (multiplication of formula_3 and formula_4) into a series of very simple operations (evaluation of formula_9) on random bits. More generally speaking, stochastic computing represents numbers as streams of random bits and reconstructs numbers by calculating frequencies. The computations are performed on the streams and translate complicated operations on formula_3 and formula_4 into