INT 0x10 - 0x05 - Select Active Display Page

Request/Call:

reg	value	descr
AH	0x05
AL	parm	new page number (see Video Pages)

for PCjr only:

reg	value	descr
AL	0x80	read CRT/CPU page registers
	0x81	set CPU page register BL: CPU page register
	0x82	set CRT page register BH: CRT page register
	0x83	set bot CRT and CPU page register BL: CPU page register BH: CRT page register

reg	descr
BH	CRT page register
BL	CPU page register

returns data from BIOS DATA AREA locations 40:50, 40:60 and 40:61
the 6845 can also be used to read the cursor position
the return data can be circumvented by direct port I/O to the 6845 CRT Controller since this function returns the data found in the BIOS Data Area without actually checking the controller