Byte of the 8080 and the 8086, used in early personal computers, could also perform a small number of operations on the four-bit pairs in a byte, such as the decimal-add-adjust (DAA) instruction. A four-bit quantity is often called a nibble, also "nybble", which is conveniently represented by a single hexadecimal digit. The term "octet" is used to unambiguously specify a size of eight bits. It is used extensively in protocol definitions. Historically, the term "octad" or "octade" was used to denote eight bits as well at least in Western Europe; however, this usage is no longer common. The exact origin
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