Int 15 Fn 02  - Cassette - Read Data (pc And PCjr Only)                    [B]

   AH = 02h
   CX = number of bytes to read
   ES:BX -> buffer

Return: CF clear if successful
       DX = number of bytes read
       ES:BX -> byte following last byte read
   CF set on error
   AH = status (see below)

See Also: AH=00h"CASSETTE",AH=03h"CASSETTE"

Values for status:
 00h   successful
 01h   CRC error
 02h   bad tape signals
 04h   no data
 80h   invalid command
 86h   no cassette present