The Tandy TRS-80 line of computers which were the bestselling 8-bit computers until 1982 also didn't have commands for "the DOS" commingled with BASIC. The vari

The Tandy TRS-80 line of computers which were the bestselling 8-bit computers until 1982 also didn't have commands for "the DOS" commingled with BASIC. The various DOS's available for the platform booted directly from disk. The basic in ROM on IBM PCs was cassette basic and only supported loading and saving from cassette tapes. Although there might have been an obscure clone manufacturer or two which supported a cassette tape interface, in general clone makers didn't so there was no needed for an embedded cassette basic. Even IBM didn't support a cassette tape interface after the original IBM PC (5150). This meant that for years you could boot an IBM computer to cassette basic but not actually load or save any BASIC programs once you had done so.