MCP-1600

   A processor made by Western Digital, consisting of at least
   four separate integrated circuits, including the control
   circuitry unit, the ALU, two or four ROM chips with
   microcode, and timing circuitry.

   The ALU chip contained twenty-six 8-bit registers and an
   8-bit ALU, while the control unit supervised the moving of
   data, memory access, and other control functions.  The ROM
   allowed the chip to function as either an 8- or 16-bit chip,
   with clever use of the 8-bit ALU.  Further, microcode
   allowed the addition of floating-point routines (40 + 8 bit
   format), simplifying programming (and possibly producing a
   floating-point coprocessor).

   Two standard microcode ROMs were available.  This
   flexibility was one reason it was also used to implement the
   DEC LSI-11 processor as well as the WD Pascal
   Microengine.

   (1994-11-18)