Date: Sun, 21 Dec 1997 13:47:54 +0200 (IST)
From: Eli Zaretskii <eliz AT is DOT elta DOT co DOT il>
To: yin tan cui <z2191317 AT student DOT unsw DOT edu DOT au>
cc: djgpp AT delorie DOT com
Subject: Re: how to get a copy of video memory ?
In-Reply-To: <3499E3E6.5837@student.unsw.edu.au>
Message-ID: <Pine.SUN.3.91.971221134735.8399N-100000@is>
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On Fri, 19 Dec 1997, yin tan cui wrote:

> I'm writing a program that uses these screen functions in "pc.h", such
> as ScreenPutString() to print some colored strings to the screen. The
> problem I'm having is that when the number of lines I printed exceeds
> the max row number(eg: when I'm using a 80x25 dos window, 
>        No. of lines printed > 25)
> 
> I guess I need to update the screen in this case. ie. use 
> void ScreenUpdate(void *buf)
> where buf should contain an exact replica of the video memory, including
> the chars and their attributes.

I think you need to scroll the screen, not to update it.  You *can*
achieve the scroll effect by using ScreenRetrieve followed by
ScreenUpdate, but that's another matter.

> Am I right ? and if so, How to get an exact replica of video memory ?
> if I'm wrong, What should I do ?

If you use ScreenRetrieve, then you already get the exact replica.