Path: utzoo!mnetor!uunet!husc6!bloom-beacon!gatech!ncsuvx!sam
From: sam@ncsuvx.ncsu.edu (Sam "SammyBake" Moore)
Newsgroups: comp.sys.ibm.pc
Subject: Re: GRAFTABL.COM: how do I detect if it is loaded?
Message-ID: <1635@ncsuvx.ncsu.edu>
Date: 29 Mar 88 13:27:33 GMT
References: <942@rmi.UUCP>
Reply-To: sam@ncsuvx.UUCP (Sam "SammyBake" Moore)
Organization: NCSU Computing Center, Raleigh, NC
Lines: 47

In article <942@rmi.UUCP> marvin@rmi.UUCP (Martin Freiss) writes:
>
>This may have been asked before on the net, so if you consider it a dumb
>question, my abject apologies :-).
>
>For a program (written in C) that operates on the hercules graphics card in
>graphics mode, I need the extended ASCII-character set (characters from
>decimal 128 to 255) to display the german 'Umlaute'.
>Being lazy but inventive :-), I use the ASCII charactertable in the ROM to
>display text in graphics mode; however, this only giv%s me the 'normal'
>letters. 

On a Hercules graphics card in graphics mode you use the ASCII character table
in ROM? What mode are you working in and what Herc card is it? Can you explain
how you use this table? I assumed this table would be useless to you in the
(720 x 348) 2 color Hercules mode. 

>         Now GRAFTABL.COM provides this extended character set, but I
>need to ascertain if it has been loaded in my program prior to switching into
>graphics mode. If anybody on the net has ideas on how to do this, I would be
>grateful for any hints you might be able to give. Just checking if the int 1fh
>vector points to 0000:0000 does not seem to work reliably on all machines.
>...
>Again, any hints on how to do this would be appreciated.
>I'm running DOS3.3 on an AT-clone, if it matters.

I would get an EGA card and dump the character table for the mode you need
using BIOS. Then I would use the table in my program. If you can still use
BIOS text support in the mode you are using then you can replace the vector
that points the top 128 and have it point to your table. You can also replace
the original vector in case something else is using it. If the use of the
table produced by BIOS is not "free", then there are public domain fonts. Or
you can write your own font editor; easy to write but no fun to use.

I am confused how you can use the "ROM character table" in Herc graphics mode.
Since, you don't have BIOS support for it then I can't see it being useful. But,
when you talk about the "top 128" characters I assume you are using CGA graphics
modes. 




-- 
Sam Moore                          ||\\  || //==\\ //==\\ ||   ||
NCSU Computing Center              || \\ || ||     ||==\\ ||   ||
Raleigh, NC                        ||  \\|| ||         || ||   ||
sam@ncsuvx.ncsu.edu                ||   \\  \\==// \\==||  \\==//