Artifact Details


Single-board computer

Catalog Number



Physical Object


Circa 1972


Sutherland, James F.

Place Manufactured


Identifying Numbers

Other number 2838A73 This number appears in several places on the PC board.


overall: 7/8 in x 11 1/2 in x 6 1/4 in


The ECHO-IV had three serious problems: large physical size, huge power
consumption, and slow speed. When DTL and TTL integrated circuits became
widely available in the late 1960s, Jim Sutherland believed that he
could design a single-board computer that could execute ECHO-IV commands
faster, and use significantly less power. He called it "ECHO-XL" because
he believed that it would operate 40 times faster than the previous
system. Design began October 18, 1971. but he soon found that more than
one board would be needed if he used standard ICs. On April 8, 1972, he
abandoned the original design, and implemented sixteen Intersil IM5600
proms in the instruction execution sequencer. Two Texas Instruments
SN7481 arithmetic devices performed all of the arithmetic functions. The
single-board ECHO-XL was built at home, and was not completely checked
out before it was abandoned on September 13, 1974, At that time, it was
clear that micro-processors would dominate all future designs of small
computer systems. The ECHO-XL met all of the original goals of reduced
size, faster speed, and low power consumption (12 watts).

The object includes a wooden enclosure measuring 1.625" x 12.25" x 7.5".


Digital computer/personal computer/single-board computer


Gift of James F. Sutherland

Lot Number