Member Avatar for fares_silawi

Respected members: I've been asked to write and run an assembly code to print my name in the middle of a 80X25 Text screen such that, each character in my name will show different background, foreground colors also some characters will be blinking with intense light! the problem is that I can't find the attributes of colored background and intensity stuff. Do u think any of you can help me? and Thanks in advance. here's what I've written so far but unfortunately still missing the colors attributes:

MOV AX, 0B800H
MOV DS, AX
MOV BX,159
MOV AX, 12
MUL BX
ADD AX, 40
MOV SI, AX

MOV [SI], 'F'
INC SI
INC SI
MOV [SI], 'A'
INC SI
INC SI
MOV [SI], 'R'
INC SI
INC SI
MOV [SI], 'E'
INC SI
INC SI
MOV [SI], 'S '
INC SI
INC SI
mov [SI], 'H'
INC SI
INC SI
MOV [SI], 'A'
INC SI
INC SI
MOV [SI], 'S'
INC SI
INC SI
MOV [SI], 'A'
INC SI
INC SI
MOV [SI], 'N'

mov ax, 4c00h
int 21h

  • 3 Contributors
  • 2 Replies
  • 3K Views
  • 6 Days Discussion Span
  • Latest Post Latest Post by Goalatio
Member Avatar for NotNull

The text attribute byte immediately follows the character byte
in video ram.
Text attributes can also be specified with INT 10/09 Write Char
and Attr at hardware cursor.

Here is the format of the text attribute byte:
[HHHHLLLL]
H-High Nibble= Background Color
L-Low Nibble= Foreground Color

mov cx, b800h
mov es, cx
mov ah, 40h ; Red Background Black foreground
mov al, 'A'     ; Character 65
mov [es:0000], ax ; print at X 0 Y 0

To calculate an offset into video ram using zero-based
XY coordinates for 80x25 screen:
(Y*80+X)*2

Member Avatar for Goalatio

Notnull pretty much covered it, but made this for you quick.

[org 0100h]

[section .text]

main:
	mov cx,our_message_l	;Load amount of chars to print in CX
	dec cx
	dec cx
	dec cx			;Lower cx by 3 as not to display "13, 10, "$"" on the colored line.
	mov bl,[color]		;Load color value in BL
	mov ah,9		;Function 9x10 - Print char with attribute
	mov al,0		;Null AL so that it does not print chars by default
	int 10h			;Call BIOS and display the colored bit..

		;We can skip 'mov ah,9' as we already have 9 bits in AL
	mov dx,our_message
	int 21h			;Use DOS v-21h to display string

	mov ah,4ch		;Exit routine..
	mov al,0		;Exit with ERRORLEVEL of 0
	int 21h	




[section .data]

color db 64h
our_message db "Hello, world.", 13, 10, "$"
our_message_l EQU $-our_message			;Get message length
Be a part of the DaniWeb community

We're a friendly, industry-focused community of developers, IT pros, digital marketers, and technology enthusiasts meeting, networking, learning, and sharing knowledge.