Function 05h    Select Active Page - set page number for services 6 and 7 
entry   AH      05h 
	AL      number of new active page 
		0-7     modes 00h and 01h (CGA) 
		0-3     modes 02h and 03h (CGA) 
		0-7     modes 02h and 03h (EGA) 
		0-7     mode 0Dh (EGA) 
		0-3     mode 0Eh (EGA) 
		0-1     mode 0Fh (EGA) 
		0-1     mode 10h (EGA) 
		0       set address of graphics bitmap buffer (modes 60h,61h) 
			BX      segment of buffer 
		0Fh     get address of graphics bitmap buffer (modes 60h,61h) 
			BX      segment of buffer 
for PCjr only: 
	AL      80h to read CRT/CPU page registers 
		81h to set CPU page register to value in BL 
		82h to set CRT page register to value in BH 
		83h to set both CPU and page registers 
		    (and Corona/Cordata BIOS v4.10+) 
	BH      CRT page number for subfunctions 82h and 83h 
	BL      CPU page register for subfunctions 81h and 83h 
Function 05h    Select Active Page - set page number for services 6 and 7
return  standard PC  none 
	PCjr         if called with AH bit 7=1 then 
		     BH      CRT page register (if AL = 80h) 
		     BL      CPU page register (if AL = 80h) 
	DX      segment of graphics bitmap buffer (video modes 60h,61h; AL=0Fh) 
note 1) Mono adapter has only one display page 
     2) CGA has four 80x25 text pages or eight 40x25 text pages 
     3) A separate cursor is maintained for each display page 
     4) Switching between pages does not affect their contents 
     5) Higher page numbers indicate higher memory positions 
 
Sample Code:
\Asm\Lib\BIOS.INC -@BIOSVidPageSet	  MACRO page