Color print routines

[KieranFoot]

Hi can anyone help me with asm colour print routines?

I have one at home but i can't get it to work. It print the character in the right colours but then it starts to move the cursor and beep continousley!!!

Please can someone help?

[Therx]

You just need to change the attribute byte (the second)

eg.
Video Mem Layout

Code: Select all

Byte    0      1       2        3
Data Char  Att.  Char   Att.

The layout of the attribute byte is here

Pete

[KieranFoot]

At the moment i'm using bios print routines and so have not yet touched on any others!!!

[Therx]

In that case I don't know. But honestly writing a 80x25 text mode (default) video driver is as easy as anything else in OS Dev. Using graphics modes are another matter but you won't need them for a while.

Pete

[df]

why still trying to use real mode??

[KieranFoot]

Why not ?

[Tim]

Because it's a lot harder to program for than protected mode.

[KieranFoot]

oh

O.K. one question!

How to tramsfer contents of al to a location in memory
in other words remaking the poke function of qbasic!!!

[Ozguxxx]

mov byte [segment:offset], al

Well, I think that is not so hard to implement in asm, I think you might want to revisit some basic assembly, since this question is not related with os programming.

[KieranFoot]

could i write an opcode to say 0001:0001 then jump to it using JMP 0001:0001, if nt how would I jump to a memory location.

[Tim]

There are many ways to JMP to a particular memory address, and JMP FAR xxxx:yyyy is one of them. Read the NASM manual or the Intel manual for more info.

PS: you don't want to do JMP 0001:0001 as that area is occupied by the interrupt vector table.