Dubno was born in Brooklyn, New York. His family moved to the Bronx where he attended the Bronx High School of Science. In the 1970s, very few high schools and individuals had computers. Bronx Science had an IBM 1620 and an HP 2000E computer but no formal programming classes. Dubno taught himself how to program on the school computers, nearby Lehman College’s IBM System/360 (until it was stolen in 1978), and his own North Star Horizon computer.
He attended Rensselaer Polytechnic Institute in 1981 and left in his freshman year.
Dubno founded Megasoft in 1982 and released the video game Megalegs, for Atari computers.
Starting in 1984, he designed and built a robot that talked, moved, had a working arm, navigated using sonar, and had an infrared GPS-like location system.
He maintains a unique workshop in his Manhattan townhouse.