AH = 42h AL = origin of move: 00 = beginning of file plus offset (SEEK_SET) 01 = current location plus offset (SEEK_CUR) 02 = end of file plus offset (SEEK_END) BX = file handle CX = high order word of number of bytes to move DX = low order word of number of bytes to move on return: AX = error code if CF set (see DOS ERROR CODES) DX:AX = new pointer location if CF not set - seeks to specified location in file