OSDev.org

The Place to Start for Operating System Developers
It is currently Thu Apr 25, 2024 8:39 am

All times are UTC - 6 hours




Post new topic Reply to topic  [ 2 posts ] 
Author Message
 Post subject: Help with VESA
PostPosted: Sat Oct 02, 2004 6:45 pm 
Im in the process of trying to implement VESA 2.0 with a Linear Frame Buffer. I have successfully gotten my assembly code to detect the presence of VESA and store the VBE info structure in a chosen memory location. I would now like to print out the version of the VESA supported. In the VESA 2.0 docs, it says this:
Quote:
The VbeVersion is a BCD value which specifies what level of the VBE standard is implemented in the software. The higher byte specifies the major version number. The lower byte specifies the minor version number.

Note: The BCD value for VBE 2.0 is 0200h and the BCD value for VBE 1.2 is 0102h. In the past we have had some applications misinterpreting these BCD values. For example, BCD 0102h was interpreted as 1.02, which is incorrect.
How do I display it?

I originally tried calling the '0200h' (VBE 2.0) from my real mode print_msg that uses bios int 10h, but it wouldnt display anything.

Thanks for the help in advance.


Top
  
 
 Post subject: Re:Help with VESA
PostPosted: Sat Oct 02, 2004 8:58 pm 
You print it the same way you'd print any integer. Until there are either 10 major versions or 10 minor versions of the VBE standard (read as: almost certainly never), you can pretty much ignore the fact that it's officially a BCD value. BCD encoding == normal encoding for values less than 10.


Top
  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 2 posts ] 

All times are UTC - 6 hours


Who is online

Users browsing this forum: iansjack, Majestic-12 [Bot] and 231 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
Powered by phpBB © 2000, 2002, 2005, 2007 phpBB Group