HP Vectra Technical Reference Manual page 348

INT
Function Function
Hex Equate
Value Definition
74H
Reserved (IRQ 12)
~
75H
Coprocessor
(IRQ 13)
76H
Hard Disc ISR (IRQ 14)
77H
Reserved (IRQ 15)
78H-7FH
Not Used
80H-FOH
Reserved
F1H-FFH
Not Used
A.3 EX-BIOS Drivers and Function-s
Many additional features of the HP system can be accessed through the software interrupt INT
6FH. To call the EX-BIOS extensions, the BP register must contain the vector address of the
desired driver, the AH register must contain the function code, and the AL register must contain
the subfunction code. The rest of the registers are available for passing data and returning data
to and from the routine.
In general the AX, BP and DS registers are not preserved. They must be preserved by the calling
routine if it needs them. See Section 2 for an example showing how EX-BIOS drivers are called.
Table A.3
EX-BIOS Drivers and Functions
Vector
Func. Function
Address Value Equate Definition
OOOOH
V_SCOPY
Copyright Notice Routine
0006H
V_DOLITILE Nap Routine (IRET)
OOOCH
V_PNULL
Null device driver
0012H
V_SYSTEM
System Management Functions
0012H 00
F_ISR
Interrupt service routine
(unsupported)
0012H 02
F_SYSTEM Standard driver functions
0012H
02/00
SF_INIT System initialization
BIOS Interrupts 339