Path: utzoo!attcan!uunet!fernwood!apple!fox!portal!cup.portal.com!cliffhanger
From: cliffhanger@cup.portal.com (Cliff C Heyer)
Newsgroups: comp.sys.ibm.pc
Subject: Why no graphics in text mode?
Message-ID: <25820@cup.portal.com>
Date: 11 Jan 90 16:01:02 GMT
Organization: The Portal System (TM)
Lines: 24

I'm trying to figure out why there is this division 
between text and graphics modes with PCs. 

It seems logical that it should be possible to write 
directly to the same video memory being used for 
text display and place graphics with the text.  But 
when you try it the graphics are "forced" into 
different memory if you don't change to a 
combination text & graphics mode. I can't change 
modes because other object-code only libraries are 
locking me into text mode. Also when you change 
modes, you loose all that you had in the previous 
mode until you switch back.

I'm assuming that each screen pixel is represented 
by a bit in memory (or several bits) even in text 
mode - but in text mode the bits are written with 
bit maps from the BIOS.

Why lock people out of this memory just because the 
BIOS is writing there? Is this only a convention 
that I can bypass by using the right library? 

Please post, Cliff