NASM - The Netwide Assembler

NASM Forum => Programming with NASM => Topic started by: Wannabe Developer on March 03, 2011, 03:56:15 AM

Title: I can write to video memory, but one prob!
Post by: Wannabe Developer on March 03, 2011, 03:56:15 AM

I'm sure you're probably getting a little tired of my constant posts by now, but please bear with me. I recently came across some code that writes to video memory. I mad a binary COM file from it and launched it, and it works! Well, actually what happens is the screen goes black and red horizontal lines go across it. Perchance there's someone who'd tell what exactly is happening? I really want to make sure I know because I don't want to accidentally destroy my computer!

Title: Re: I can write to video memory, but one prob!
Post by: Keith Kanios on March 03, 2011, 04:25:11 AM

Review THIS OSDev.org Wiki Article (http://wiki.osdev.org/Drawing_In_Protected_Mode).

Title: Re: I can write to video memory, but one prob!
Post by: Wannabe Developer on March 03, 2011, 04:45:30 AM

Quote from: Keith Kanios on March 03, 2011, 04:25:11 AM

Review THIS OSDev.org Wiki Article (http://wiki.osdev.org/Drawing_In_Protected_Mode).

Great resource BUT from what i saw it was in C. What I'd like to know is how you can go about that safely in NASM. Also, it is possible to just print pixels on the command prompt window?

Title: Re: I can write to video memory, but one prob!
Post by: Keith Kanios on March 03, 2011, 06:10:15 AM

Yes, it is safe.

Try THIS (http://petesqbsite.com/sections/tutorials/tuts/asm_in_qb.htm) tutorial.

Title: Re: I can write to video memory, but one prob!
Post by: David Stone on March 26, 2011, 06:42:25 AM

Yeah this tutorial is very helpful. I used it,