The Massachusetts Computer Corporation (MASSCOMP) was a computer manufacturer based in Westford, Massachusetts. Originally conceived by C. Forbes Dewey of MIT and inventor Chester Schuler, it was founded formally in 1981. Its target market was real-time computing, with a focus on high-speed data acquisition. Its major innovation was that it created the first widely available computer product which was able to sample analog signals at one million samples per second and store the resulting data to disk continuously. Given the technology available at the time—Motorola 68000 series CPUs of only a few megahertz in speed and slow disk drives—this product represented quite a technological achievement.

The MASSCOMP MC-500 is a 68000-based microcomputer running a real-time variant of the Unix operating system.[1] For a small company, MASSCOMP incorporated a number of ambitious and innovative projects in addition to Real-Time Unix, including their own C and Fortran compiler, a block diagram language known as "Laboratory Workbench" that allowed visual programming of real time systems to connect real-time analog inputs and outputs to signal processing operations and interactive virtual instruments for data display, and their own high level graphics subsystem.

MASSCOMP grew to about $65 million in sales per year and ultimately purchased Concurrent Computer Corporation in 1988[2] in a "junk bond deal" and assumed the Concurrent name. The successor company later moved its headquarters to Atlanta, Georgia.