IEI Integration NANO-QM770 - Manual (Page 186)

NANO-QM770 EPIC SBC
Page 171
D.3.2 Enable the DIO Output Function
The BIOS interrupt call INT 15H controls the digital I/O. An assembly program to enable
digital I/O output functions is listed below.
MOV AX, 6F09H Sets the digital port as output
MOV BL, 09H
INT 15H Initiates the INT 15H BIOS call