nybble

From nibble (“small, quick bite”), with the i changed to y by analogy with byte.

nybble (plural nybbles)

1. (computing) Alternative spelling of nibble (“unit of memory equal to half a byte, or chiefly four bits”)
   • 1978 May 22, William B. Adams, “Letters to the Editor: Query on Abacus”, in E. Drake Lundell Jr., editor, Computerworld: The Newsweekly for the Computer Community, volume XII, number 21, Newton, Mass.: CW Communications, →ISSN, →OCLC, page 26, column 4:

     I own several abaci and two books on how to use them, but they all have four counters below the bar and one counter above it. […] The bottom four counters of each abacus can be used to represent a "nybble," and the upper counter on each can be used for parity.

   • 1983 June, Steve Ciarcia, “Ciarcia’s Circuit Cellar: Use ADPCM for Highly Intelligible Speech Synthesis”, in Lawrence J. Curran, editor, Byte: The Small Systems Journal, volume 8, number 6, Peterborough, N.H.: Byte Publications, McGraw-Hill, →ISSN, →OCLC, page 41, column 1:

     At every negative-going transition it reads a 4-bit ADPCM nybble (there are 2 nybbles per byte) and stores it in a memory-resident table.

   • 1985, Ronald C. Emery, “General Sequential Circuitry”, in Digital Circuits: Logic and Design (Electrical Engineering and Electronics; 25), New York, N.Y.; Basel, Basel-Stadt: Marcel Dekker, →ISBN, page 171:

     Data is being received by a system in serial sequences of four bit nybbles. (A nybble is usually defined as a four bit grouping.) […] Our mission, should we decide to accept it, is to test each nybble and determine whether or not the four bits constitute a valid BCD (8421) number.

   • 2005, Clive “MAX” Maxfield, Alvin Brown, The Definitive Guide to How Computers Do Math […], Hoboken, N.J.: Wiley-Interscience, John Wiley & Sons, →ISBN, page 20:

     Similarly, it's easy to convert a binary number such as %1100011010110010 into its hexadecimal equivalent. All we have to do is to split the binary value into 4-bit nybbles and to map each nybble onto its corresponding hexadecimal digit.