[comp.sys.ibm.pc] Is there a Low-Level Screen Blank for EGA?

ir332@sdcc6.ucsd.EDU (Jeff Miller) (01/21/88)

Is it possible, from within a program, to turn off an EGA screen 
so that it won't display anything until turned back on (about 1
second)?

This need arises because of an apparent bug in Borland's Graphics
Driver for Hercules cards in Pascal version 4.0.  The bug/feature is
that the driver initializes the card to use both pages of graphics
memory.  In a two-monitor system, however, only the first page can
be used, because the second page conflicts with the memory locations
for EGA/CGA.  A short-term work-around for my purposes would be to
turn off the EGA screen while I use the Herc screen, but I can't
figure out how to do it (from IBM EGA technical ref manual).

Any help would be greatly appreciated.

        Jeff Miller        ARPA: ir332@sdcc6.ucsd.edu
	U. C. San Diego
	Dept Psychology, C-009
        La Jolla, CA  92093