68020

Motorola 68020
68020
MC68020

   <processor> A {microprocessor} from {Motorola}.  It was the
   successor to the {Motorola 68010} and was followed by the
   {Motorola 68030}.  The 68020 has 32-bit internal and external
   data and address buses and a 256-byte {instruction buffer},
   arranged as 64 {direct-mapped} 4-byte entries[?].

   The 68020 added many improvements to the 68010 including a
   32-bit {ALU} and external {data bus} and {address bus}, and
   new instrucitons and {addressing modes}.  The 68020 (and
   68030) had a proper three-stage {pipeline}.

   The new instructions included some minor improvements and
   extensions to the supervisor state, some support for
   {high-level languages} which didn't get used much (and was
   removed from future 680x0 processors[?]), bigger (32 x 32-bit)
   multiply and divide instructions, and bit field manipulations.

   The new adderessing modes added another level of indirection
   to many of the pre-existing modes, and added quite a bit of
   flexibility to various indexing modes and operations.

   The {instruction buffer} (an {instruction cache}) was 256
   bytes, arranged as 64 direct-mapped 4-byte entries.  Although
   small, it made a significant difference in the performance of
   many applications.

   The 68881 and the faster 68882 {FPU} chips could be used with
   the 68020.

   The 68020 was used in many models of the {Apple Macintosh} II
   series of {personal computers} and {Sun} 3 {workstations}.

   (2001-03-07)
    

68020 -- U.S. ZIP code
   Municipality (1990):  DECATUR, Nebraska
   All ZIPs for this municipality (1990):
                         68020
   Population (2000):    905
   Housing Units (2000): 520
   Land area (2000):     84.653834 sq. miles (219.252413 sq. km)
   Water area (2000):    1.356284 sq. miles (3.512760 sq. km)
   Total area (2000):    86.010118 sq. miles (222.765173 sq. km)
   Located within:       Nebraska (NE)
   Location:             41.988034 N, 96.265457 W