Unauthorized software copying began to be a problem when floppy disks became the common storage media. The ease of copying depended on the system; Jerry Pournelle wrote in "BYTE" in 1983 that "CP/M doesn't lend itself to copy protection" so its users "haven't been too worried" about it, while "Apple users, though, have always had the problem. So have those who used TRS-DOS, and I understand that MS-DOS has copy protection features". Apple and Commodore 64 computers were extremely varied and creative because most of the floppy disk reading and writing was controlled by software (or firmware), not by hardware. The first copy protection was for cassette tapes and consisted of a loader at the beginning of the tape, which read a specially formatted section which followed.