[comp.unix.wizards] Words about bits and bytes

V2002A%TEMPLEVM.BITNET@wiscvm.wisc.EDU (07/28/87)

Keywords : byte *why* wordsize
Hi,

        I found the following in Tannenbaums 'Structured Computer
Organization'...

"Memories consist of a number of CELLS (or LOCATIONS)...
 Each cell has a number, called its address...

 The number of bits per cell for some computers that have been sold
 commercially follows.

 Burroughs B1700         1 bit per cell
 IBM 370                 8 bits per cell
 DEC PDP-8              12 bits per cell
 IBM 1130               16 bits per cell
 DEC PDP-15             18 bits per cell
 XDS 940                24 bits per cell
 Electrologica X-8      27 bits per cell
 XDS SIGMA 9            32 bits per cell
 Honeywell 6180         36 bits per cell
 CDC 3600               48 bits per cell
 CDC Cyber 70           60 bits per cell

      On some machines, the term WORD is used in place of cell.  On other
 machines, especially machines with eight bits per cell, the term BYTE is
 used instead of cell, and the term "word" is reserved for two bytes, or
 four bytes, depending on the machine.  This situation, unfortunately,
 can lead to much confusion.
      The significance of a cell is that it is the smallest addressable
 unit."

 Tannenbaum, Andrew S.: STRUCTURED COMPUTER ORGANIZATION. Englewood
 Cliffs, N.J.: Prentice Hall, 1976; pp 25-27.