mfinegan@uceng.UC.EDU (michael k finegan) (09/23/90)
I am using a VGA board under SCO 386 unix. As such, I can't call the video bios to select video modes, and (for reasons that are a long story) want to reset the board when leaving my subroutine. If I run the routine under DOS, int 10h function 0 cleans up after my routine nicely. The video bios apparently does more than just change mode, since without the bios call, I can't reset the VGA properly (under DOS or UNIX). I have tried saving and restoring all registers (using Ferraro 'Prg.s guide to EGA&VGA cards' book), and even resetting sequencer and board using sequencer register reset and mode control register hardware reset. 1) Are there known typo's in the Ferraro book ? Attribute controller registers 11h and 13h: Attr. Cntrl. register 11H returns non-zero value when read, even though border color is black (i.e. value of 0h). I suspect info. on Horizontal Pixel Panning register (13h) is wrong; FFh must be used to get no shift (book implies should be 0h). 2) What might be going on in int 10h fn. 0h that creates some other sort of reset (than those tried above) ? Thanks, Mike Finegan mfinegan@uceng.UC.EDU