I am writing a DOS TSR program that writes to video page 1 of the video memory. The problem is that upon certain conditions the TSR should switch the current video page (normally 0) to the video page that the TSR has been writing screen data to (in this case video page 1).
Normally to switch video pages I would invoke BIOS interrupt 0x10, Function 5 (AH), and video page number in AL.
However, calling the video interrupt always corrupts the screen when invoked from an interrupt handler routine.
Thus, I am forced to look for ways to change the active video page without using the BIOS functions.
Can anyone suggest a way of achieving this from an Interrupt Service Routine?