Stewart started Zebra Systems, Inc., in March 1983.
He earned a Bachelor of Science Electrical Engineering degree from Rutgers, took 30 credits of graduate school courses in Biomedical Engineering at the University of Pennsylvania and worked in aerospace designing test equipment for electrically-initiated explosive devices and inertial navigation equipment.
Later, he worked for ADT Security Systems designing fire alarm systems for high-rise buildings, including a fire-command station for high-rise buildings based on the Intel 8008 with 12K RAM that was coded in assembly language.
In 1983, he became so enthusiastic about the advent of hobby computers, and in particular the Timex/Sinclair 1000, that he quit his job as plant manager of a manufacturing company and started Zebra Systems, Inc., to design, manufacture, and market products for the Timex/Sinclair market.
He designed a keyboard-beeper, joystick adapter, A/D converter and a speech-synthesizer for the TS1000, TS1500, and TS2068. It was a small company, and at its peak, it had six employees; Newfeld was the hardware designer, manager/president, and chief cook and bottle washer. Zebra had a computer programmer; two production people who assembled, soldered and tested product; and one general assistant hobby computer enthusiast. Nearly everyone pitched in with customer service duties, shipping clerk, etc.
Newfeld visited fall computer shows in London, England, two years in a row looking for products to import, visited Memotech and the Timex factory in Portugal. He imported a small quantity of floppy disk controllers and drives from Timex for the TS2068 computer.
