Percom started after the meeting that produced the Kansas City standard for storing data on cassette tapes.

The final version of the standard was written in February 1976, co-authored by Lee Felsenstein and Harold Mauch.

Mauch published an article on the technical aspects of the standard in the next month's Byte magazine, entitled "Digital Data on Cassette Recorders".

[3] Mauch and his wife Lucy started what was originally PerCom Data that same month, selling the CIS-30 adaptor allowing any portable cassette player to be connected to the Motorola 6800-based micros from SWTPC.

In 1979, the company branched out into the TRS-80 market, starting with the Percom Separator, and add-on device that corrected deficiencies in Radio Shack's own floppy disk interface.