scott@blueeyes.kines.uiuc.edu (scott) (10/20/90)
I'm writing some software to redefine the character set on a VGA. Currently, I'm using BIOS interrupt 0x10 to copy the modified character set into the VGA character generator's memory; that works fine. The problem comes in when the mode is changed (i.e. when I type 'mode co80 at the DOS prompt, the default character set is restored, wiping out the redefined character set). I'd like to find some way to "protect" my modified character set. My first thought is to chain into the video BIOS INT10 vector and intercept any mode change function calls. If the call will result in a mode change (and the loss of the redefined character set), then my new handler will call the old one, and then re-load the new character set. Unfortunately, this approach involves some resident code (a TSR or device driver. Is there a better approach? (In this context, "better" means "simpler to implement" and/or "does not require any stay-resident code"). I suppose I should also point out that I want the new character set to remain active in more than one application - this would be a non-problem if the new characters were confined to just one application program. Any ideas? -- Scott Coleman khan@ux1.cso.uiuc.edu University of Illinois at Urbana-Champaign