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 PascalMicroengine.

(1994-11-18)