User`s manual

DIGITAL-LOGIC AG MSLB-P5 Manual V0.3
PRELIMINARY 204
Continued
61h Get Device Count
Entry:
short FAR (* entryPoint) (Function, Switch, Count,
MaxCount, StructSize, BiosSelector);
short Function;
short Switch;
unsigned short FAR *Count;
unsigned short FAR *MaxCount;
unsigned short FAR *StructSize;
unsigned short BiosSelector;
62h Get Priority and Table
Entry:
short FAR (* entryPoint) (Function, Switch, Priority, Table,
BiosSelector);
short Function;
short Switch;
unsigned char FAR *Priority;
unsigned char FAR *Table;
unsigned short BiosSelector;
63h Set Priority
Entry:
short FAR (* entryPoint) (Function, Switch, Priority,
BiosSelector);
short Function;
short Switch;
unsigned byte FAR *Priority;
unsigned short BiosSelector;
64h Get IPL Device from Last Boot
Entry:
short FAR (* entryPoint) (Function, IPLEntry, BiosSelector);
short Function;
unsigned short FAR *IPLEntry;
unsigned short BiosSelector;
16.7 BIOS Data Area
The BIOS keeps information about the current operating environment of the AT system in the BIOS
Data Area. The normal way to access this information is by means of the BIOS Services, described
above. The BIOS Data Area is located from physical address 400h to 501h.
BIOS Data Area Description
Offset Size Description
00 2 Com1 address
02 2 Com2 address
04 2 Com3 address
06 2 Com4 address
08 2 Lpt1 address
0A 2 Lpt2 address
0C 2 Lpt3 address
0E 2 LPT4/EBDA address*
10 2 Equipment installed:
Bit Definition
0 Not used
1 Math coprocessor installed
2 PS/2 mouse installed
3 Not used
4,5 Initial video mode:
00 = EGA/VGA
01 = 40x25 CGA
10 = 80x25 CGA
11 = Monochrome
6,7 Diskette drives:
00 = 1 drive
01 = 2 drives
10 = 3 drives
11 = 4 drives