[comp.os.msdos.programmer] How do you synchronize screen mapped RAM updates on old CGA cards?

emmonsl@athena.ecs.csus.edu (L. Scott Emmons) (02/09/91)

I am working on a program that will run on an old 4.77 pc with one of the
wonderful old CGA cards with flicker on direct screen-mapped RAM updates.
How do you synchronize these updates to alleviate this problem?  Do you just
check a port and write on a certain value?  Any help is much appreciated...

Thanks,
-scott
			L. Scott Emmons
			---------------
	emmons@csus.csus.edu  <or>  ...[ucbvax]!ucdavis!csus!emmons
		Packet: kc6nfp@kg6xx.#nocal.ca.usa.na

emmonsl@athena.ecs.csus.edu (L. Scott Emmons) (02/09/91)

I got a great pointer to a great article on the matter (thanks Raymond!),
Dave Tutelman's 'Flicker Free' paper in pub/rjc/csip/flickerfree.Z at
math.princeton.edu for anyone else intersted.  The paper thoroughly
explains a method to do it...

			L. Scott Emmons
			---------------
	emmons@csus.csus.edu  <or>  ...[ucbvax]!ucdavis!csus!emmons
		Packet: kc6nfp@kg6xx.#nocal.ca.usa.na