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
Byte addressing systems, such as the PDP-10, use word addressing but facilitate access to individual bytes using special instructions which can access memory using a "byte pointer", which contains both a word address and the index of a specific byte within the word. Byte addressing Byte addressing refers to hardware architectures which support accessing individual bytes of data rather than only larger units called words, which would be "word-addressable". Such computers are sometimes called "byte machines" (in contrast to "word machines"). The basic unit of digital storage is called a bit, storing a single 0 or 1. Many common architectures can address