There is a lot of speculation about the origins of A/DA, because they were dabbling in effects early on.
Dave Tarnowski, started making a few effects in the 70's that seemed to catch on more in the studios than with live performers, so it's kind of hard to really pinpoint an exact company start up. I know in the mid 70's the Final Phase pedal appeared, followed by the Flanger pedal, but then Dave started making dedicated studio processors for almost a decade before the MP-1 hit the market in 1987. After that ADA phased out their effect processors, and the company was dedicated to amplification systems.
IF I'm not mistaken, the original MP-1 was discontinued in late 1992, to make way for the MP-1 Classic which was introduced at the 1993 NAMM show. (The MP-2 wasn't doing that well, since it was too cerebral for the average guitar player).
I'm sure many other members here can pitch in with what they know.
Harley