Minimal Instruction Set Computers
The term MISC refers to Minimal Instruction Set
Computers in general, and to the chips designed by
Chuck Moore at Computer Cowboys.
These chips are unusual in many ways. They are designed on
Chuck's VLSI CAD software called
They are implemented in CMOS Silicon
VLSI processes and are very small and fast. They use a CPU architecture
based on the
Forth computer language, and with only five bit instructions. The first chip
to be produced at Computer Cowboys was
MuP21 stands for Multi-Micro Processor.
With only 25 instructions MuP21 is a Minimal Instruction Set
Computer. But it is not just he instruction set that has been minimized,
much of the complexity in modern chips is gone. MuP21 is implemented in
only 7000 transistors vs millions of transistors on other modern chips.
MuP21 includes not only a Forth Engine CPU, but also a memory interface
processor, and a video output processor on the chip. With only 7000
CMOS transistors MuP21 can execute 80 million instructions per second and
only draw 50 milliwatts of power.
A paper entitled
MuP21 a High Performance MISC Processor was
published by Charles Moore and C.H. Ting in the January 1995 issue of
Ultra Technology Inc. is developing the
MISC Mail List
FOr a number of years we had a mail list setup at Rockefeller.edu
for a discussion of
various aspects of the MISC approach -- Minimal Instruction Set Chips. The
first MISC chip is out and can be ordered from
Offete Enterprises Inc. --
Ultra Technology Inc. is completing the
We have three new (3/15/2001) mail lists for related discusions:
MachineForth, ColorForth, and Nosc
MachineForth is the native assembler for MISC chips and
colorForth is about Chuck Moore and other people's
versions of Color Forth. Chuck's new
OKAD II was written in his new
Color Forth. Nosc is for discussions of No Operand
Set Computer or Minimal Instruction set computers.
To subscribe to the above mail lists send mail to:
No subject or boday is needed. Then reply to the confirmation mail
sent to you by the list without changing it. The mail lists do
have a web browsable archive. web
A free simulator for the MuP21 called S21
is available at this site. And more complex free simulators
and emulators for UltraTechnology's F21 microprocessor.