INT 15,2 - Read Blocks from Cassette (PC,PCjr only)

AH = 02

CX = count of bytes to read

ES:BX = pointer to data buffer

on return:

AH = error code if CF=1

= 1 if CRC error

= 2 data transition lost, (bit signal scrambled)

= 3 no data found on tape

DX = count of bytes actually read

ES:BX = pointer to byte following last byte read

- data is transferred in 256 byte blocks, though only the

number of bytes requested are actually stored