managers cannot be used in CONFIG.SYS.
3. At the DOS prompt for the “C” drive type phlash <enter>.
The utility will display a progress screen and tell you when the process is done. You
may need to push the reset button or cycle the power on the system to boot from
the updated BIOS.
INT17 calls to read user switch
The INT17 functions provide an easy method to implement software routines
according to whether or not a user switch is On.
Function:
0fbh
Sub-Function:
0bh
Purpose:
To read user switch
Calling Registers:
AH
0fbh
AL
0bh
DX
0ffffh
Return Registers:
Carry flag cleared if successful
AL
Switch
data
bit 0 user switch 1. 1=on, 0=off
Carry flag set if error
AL
Error
code
Comments:
This function shall be used to read the user
switch
Programming example:
/* Inline assembly code for Borland C++ 3.1 */
unsigned char aData;
asm {
MOV
AX, 0fb0bh
MOV
DX, 0ffffh
INT
17h
MOV
aData, AL
}
if (aData & 1)
printf(“U1 switch is ON\n”);
INT17 calls to read BIOS version
The INT17 functions provide the version number of the currently-installed BIOS.
Function:
0fbh
Sub-Function:
00h
Purpose:
To obtain the version number of the INT 17 BIOS
extension
Calling Registers:
AH
0fbh
AL
00h
DX
0ffffh
Return Registers:
Carry flag cleared if successful
AL
Major version number (e.g. Version 2.10
90
