[ASM x86] - Graphical Utility (Concept)

.model small
.stack 100h
   COLBOX macro C,POS,EPOS
        MOV AX, 600H
        MOV BH, C
        MOV CX, POS
        MOV DX, EPOS
        INT 10H
   endm
   CURPOS macro X,Y
        MOV AH, 2H
        MOV BH, 0
        MOV DH, Y
        MOV DL, X
        INT 10H
   endm
        .data
 UISTR    DB 'GUI TEST!$'
 GX DB 1
 GY DB 8
        .CODE
 MOV AX, @DATA
 MOV DS, AX

 ; DEFINE STORE VARS FOR DRAW PROTOCOL
 MOV DI, OFFSET UISTR
 ; PUT COLOR BOX ARROUND TEXT
 COLBOX 17H, 0505H, 060DH
 CURPOS 5,5
 CALL DRAWGUI
 LEA DI, UISTR
 CURPOS 5,6
 CALL DRAWGUI
 ; EXIT DOS
 MOV AH, 4CH
 INT 21H


;-------------------------------------
DRAWGUI PROC
        ; LOOP THROUGH STRING AND DRAW CHAR ARE X AND Y'S
        ; BLACKLISTED REGISTERS - DH, DL
        ; RELY REGISTERS - DI
        ; RETURNS LENGTH WITH BL
        ; SET CHAR COUNT TO 0
        MOV BL, 0
        ; GET STARTING CURSOR POSITION
        MOV AH, 3H
        INT 10H
        ; POSITIONS OUTPUTED TO DL, DH (X,Y)
        ; LOOP DI AND DRAW EACH CHAR AT DL, DH
        NXTCHAR:
                ; RECIEVE CHAR WITH ADDRESS OUTPUT TO BITS
                MOV BH, [DI]
                ; PRINT CHAR THEN MOVE TO NEXT
                MOV CL, DL
                MOV AH, 2H
                ;BACKUP X POSITION
                MOV DL, BH
                INT 21H
                ; POP X POSITION BACK THEN MOVE TO NEXT X
                MOV DL, CL
                INC DL
                MOV CH, BH
                ; SET CURSOR POS AT NEXT X
                MOV AH, 2H
                ; SET DEFAULT PAGE XY
                MOV BH, 0
                INT 10H
                ; CHECK IF LAST CHAR
                INC DI
                MOV BH, [DI]
                CMP BH, '$'
                JE RETURN
                ; ABSOLUTE LENGTH, WITHOUT CARRAGE RETURN
                INC BL
                JMP NXTCHAR
        RETURN:
                RET
DRAWGUI ENDP

END