ones' complement

English

Noun

ones' complement (plural ones' complements)

1. (computing) The number obtained by subtracting a given n-digit binary number from $2^{n}-1$ (which yields the same result as the logical complement).

   The ones' complement of 0xAAAA is 0x5555 on a 16-bit machine, and 0xFFFF5555 on a 32-bit machine.

2. (computing) The convention by which bit patterns with high bit 0 represent positive numbers from 0 to $2^{n-1}-1$ directly, while bit patterns with high bit 1 represent negative numbers from 0 to $-(2^{n-1}-1)$, n being the word size of the machine, and the numeric complement of a number is its ones' complement.

   Computers that use ones' complement arithmetic have two representations for zero, all 0's and all 1's.

Synonyms

• logical complement

Related terms

• complement
• diminished radix complement
• two's complement

Translations

number

• Finnish: yhden komplementti, 1-komplementti
• (deprecated template usage) {{trans-mid}}

convention

• Finnish: yhden komplementti
• (deprecated template usage) {{trans-mid}}

The translations below need to be checked and inserted above into the appropriate translation tables. See instructions at Wiktionary:Entry layout § Translations.

Translations to be checked

• Hungarian: ^{(please verify)} egyes komplemens
• (deprecated template usage) {{trans-mid}}
• Icelandic: ^{(please verify)} einundafyllitala f, ^{(please verify)} einundafylling f