Stewart Nelson

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

From a young age, Nelson was tinkering with electronics, aided and abetted by his father who was a physicist that had become an engineer. Nelson enrolled at MIT in 1963 and quickly became known for hooking up the AI Lab's PDP-1 (and later the PDP-6) to the telephone network, making him one of the first phreakers. Nelson later accomplished other feats like hardwiring additional instructions into the PDP-1. Nelson was hired by Ed Fredkin's Information International Inc. at the urging of Marvin Minsky to work on PDP-7 programs at the MIT Computer Science and Artificial Intelligence Laboratory.[1]

Nelson was known as a brilliant software programmer. He was influential in LISP, the assembly instructions for the Digital Equipment Corporation PDP, and a number of other systems. [2]

The group of young hackers was known for working on systems after hours. One night, Nelson and others decided to rewire MIT’s PDP-1 as a prank. Later, Margaret Hamilton tried to use the DEC-supplied DECAL assembler on the machine and it crashed repeatedly.