Kevin Ring wrote in a message to Mike Bilow:

>  KR> Is it possible to create a non-PM 32 bit OS/2 native program
>  KR> that uses graphics modes (such as mode 13h)?  

> You can write a 32-bit OS/2 program that runs in full-screen text mode.
> However, it would need to call at least some of the 16-bit VioXxxxx 
> API calls.

 KR> Ok.. but what I'm wondering is if it would be possible to
 KR> rewrite a game...  Let's say Doom, just as an example..  and
 KR> have that game run without requiring Presentation Manager
 KR> graphics. (IE: Run through a shell such as TSHELL). 

 KR> In other words, can OS/2 "text mode" sessions take advantage
 KR> of graphics. 

Yes.  This has serious disadvantages and can be annoying to the user, but
it is possible to get a logical screen buffer and paint into it much the
same way you would do under DOS.  Obviously, Presentation Manager itself
must have some way of painting graphics onto the screen, and it uses
precisely this facility to do so.  PM runs as a user process at Ring 3
(with some very special exceptions), and you could effectively write your
own process-level replacement for it if you really needed this.  MSHELL is
distributed by IBM as an example of how to do something similar.
 
-- Mike


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