[net.micro.pc] int10h help needed

ade@pucc-i (D. Kakarigi) (12/10/85)

Would anyone please tell me what to expect in AL after INT 10H for MS-DOS,
IBM PC-like machine, with 0FH in AL on entry?  Trying to get the video
status.  For my machine it is 7 which among other things means that the
video memory segment is at 0B000h.   Thank you.

D.K.  {decvax|harpo|ihnp4|inuxc|seismo|ucbvax}!pur-ee!pucc-i!ade

keifer@uiucdcs.CS.UIUC.EDU (12/11/85)

According to Peter Norton ("Programmer's Guide to the IBM PC"), you
should get AH=width in characters, AL=video mode, BL=page number after
doing INT 10H, AH=0FH.  He doesn't say anything about AL=0FH on
entry.

	G. P. Seaburg
	c/o keifer
	Engineering Psychology Research Lab
	Univ. of Illinois

ggl@mhuxi.UUCP (LASKARIS) (12/11/85)

> Would anyone please tell me what to expect in AL after INT 10H for MS-DOS,
> IBM PC-like machine, with 0FH in AL on entry?  Trying to get the video
> status.  For my machine it is 7 which among other things means that the
> video memory segment is at 0B000h.   Thank you.
> 
> D.K.  {decvax|harpo|ihnp4|inuxc|seismo|ucbvax}!pur-ee!pucc-i!ade

The listing of IBM BIOS in the PC `Technical Reference' (April '84) has notes
under int 10:
	(AH) = 15 CURRENT VIDEO STATE
		RETURNS THE CURRENT VIDEO STATE
		(AL) = MODE CURRENTLY SET ( SEE AH=0 FOR EXPLANATION)
		(AH) = NUMBER OF CHARACTER COLUMNS ON SCREEN
		(BH) = CURRENT ACTIVE DISPLAY PAGE
and, at AH=0, we have:
	( SET MODE (AL) CONTAINS MODE VALUE
		(AL)=0 40X25 BW (POWER ON DEFAULT)
		(AL)=1 40X25 COLOR
		(AL)=2  80X25 BW
		(AL)=3  80X25 COLOR
		GRAPHICS MODES
		(AL)=4  320X200 COLOR
		(AL)=5  320X200 BW
		(AL)=6  640X200 BW
		CRT MODE=7 80X25 B&W CARD (USED INTERNAL TO VIDEO ONLY)
		*** NOTE BW MODES OPERATE SAME AS COLOR MODES, BUT
		         COLOR BURST IS NOT ENABLED

Hope this helps.

David Laurance
mhuxi!ggl