Mouse Systems Corporation (MSC), formerly Rodent Associates, was founded in 1982 by Steve Kirsch.

Mouse Systems' optical mouse, wired to a Sun workstation and an Atari 400 running Missile Command, attracted many observers at the October, 1982 Mini/Micro '82 conference in Anaheim, California, attended by over 10000 people—and won a "best new product" award.

[3] In 1984, MSC acquired rights to Mouse Draw from Microtex Industries, written by Doug Wolfgram.

Mouse Systems wanted the software re-developed to look more like Apple's MacPaint so Wolfgram brought in co-developer John Bridges and together they re-wrote the program in C with an updated user interface and called it PCPaint.

Like all early optical mice, their debut product relied on a special metallic and reflective mousepad printed with a square grid of grey and blue tracking lines: as the device moved over the pad, light emitted by an LED was reflected by the pad onto an array of sensors whose output was processed by an on-board controller, which in turn supplied the host computer with machine-readable tracking data via an RS-232 serial port.