octal

octal

A numbering system that uses eight digits. It is used as a shorthand method for representing binary characters that use six-bits. Each three bits (half a character) is converted into a single octal digit. Okta is Greek for 8.

      Decimal  Binary   Octal
      0        000      0
      1        001      1
      2        010      2
      3        011      3
      4        100      4
      5        101      5
      6        110      6
      7        111      7

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(mathematics)

octal - Base 8. A number representation using the digits 0-7 only, with the right-most digit counting ones, the next counting multiples of 8, then 8^2 = 64, etc. For example, octal 177 is digital 127: digit weight value 1 8^2 = 64 1* 64 = 64 7 8^1 = 8 7* 8 = 56 7 8^0 = 1 7* 1 = 7 --- 127 Octal system used to be widespread back when many computers used 6-bit bytes, as a 6-bit byte can be conveniently written as a two-digit octal number. Since nowadays a byte is almost always 8-bit long the octal system lost most of its appeal to the hexadecimal system. For a brief discussion on the word `octal' see hexadecimal.