
In August 1976 at the Personal Computing show in Atlantic City, Bob Marsh of Processor Technology approached Bob Jones, the publisher of Interface Age magazine, about pressing software onto vinyl records.
The idea was to record the program on audio tape in the “Kansas City Standard” format then make a master record from the tape. Eva-Tone made “sound sheets” on thin vinyl that would hold one song.[7] These were inexpensive and could be bound in a magazine.
The May 1977 issue of Interface Age contained the first “Floppy-ROM”, a 33⅓ RPM record with about 6 minutes of “Kansas City standard” audio.
From wikipedia