Stewart Nelson is an American mathematician and programmer from the Bronx who co-founded Systems Concepts

Systems Concepts

Systems Concepts is a company co-founded by Stewart Nelson and Mike Levitt focused on making hardware products related to the DEC PDP-10 series of computers...

.

From a young age, Nelson was tinkering with electronics, aided and abetted by his physicist/engineer father. When he enrolled in MIT

Massachusetts Institute of Technology

The Massachusetts Institute of Technology is a private research university located in Cambridge, Massachusetts. MIT has five schools and one college, containing a total of 32 academic departments, with a strong emphasis on scientific and technological education and research.Founded in 1861 in...

, Nelson became known for hooking up the AI Lab's PDP-1

PDP-1

The PDP-1 was the first computer in Digital Equipment Corporation's PDP series and was first produced in 1960. It is famous for being the computer most important in the creation of hacker culture at MIT, BBN and elsewhere...

 (and later the PDP-6

PDP-6

The PDP-6 was a computer model developed by Digital Equipment Corporation in 1963. It was influential primarily as the prototype for the later PDP-10; the instruction sets of the two machines are almost identical.The PDP-6 was DEC's first "big" machine...

) to the telephone network, making him one of the first phreakers; he later accomplished other feats like hardwiring additional instructions into the PDP-1. Nelson was hired by Ed Fredkin's Information International Inc. to work on PDP-7

PDP-7

The DEC PDP-7 is a minicomputer produced by Digital Equipment Corporation. Introduced in 1965, it was the first to use their Flip-Chip technology. With a cost of only $72,000 USD, it was cheap but powerful by the standards of the time. The PDP-7 was the third of Digital's 18-bit machines, with...

programs.