; multi-segment executable file template.

data segment
sup db '  Hello the world$'
ends

stack segment
dw   128  dup(0)
ends

code segment


PILE SEGMENT PARA STACK

PILE ENDS






ASSUME CS:CODE, DS:DATA, SS:PILE



start:
; set segment registers:
mov ax, data
mov ds, ax
mov es, ax




portA equ 300h
portB equ 302h
portC equ 304h
cmd equ 306h


mov dx,cmd   ; DX= cmd register's adresse
mov al,80h   ; A,B,C are outputs
out dx,al    ; regis's main settings


call lcd_init   ; call proc


mov si,offset sup

call lcd_maintext


;===========sliding=========

mov bl,0        ; bl=0 (counter)

A:              ; bl should be 0 at this point
inc bl          ; bl= bl+1
call lcd_GTR    ; slide right
cmp bl,199
jne A           ; if bl=7 (text slided to right 7times) go B else jump back to A

B:              ; bl should be 7 at this point
dec bl          ; bl=bl-1
call lcd_GTL    ; slide left
cmp bl,0
jne B           ; if bl=0 (text slided back to left side 7times) go A else jump back to B
jmp A





;**************proc**************

lcd_maintext proc
;==================

mov bl,0

srsly:

mov al,[si]
mov dx,portA   ; DX= portA's adresse
out dx,al      ; send to portA's outputs  AL's value

mov dx,portB   ; DX= portB's adresse
mov al,11b     ; E=1 / RS=1  typing mode
out dx,al      ; validation
mov al,10b
out dx,al      ; end of validation
inc si
inc bl
cmp bl,07h
jne srsly

call lcd_sec_line


srslyy:
mov al,[si]
mov dx,portA   ; DX= portA's adresse
out dx,al      ; send to portA's outputs  AL's value
mov dx,portB   ; DX= portB's adresse
mov al,11b     ; E=1 / RS=1  typing mode
out dx,al      ; validation
mov al,10b
out dx,al      ; end of validation
inc si
cmp [si],'$'
jne srslyy


ret
lcd_maintext endp




lcd_GTR proc
;==================

mov dx,portA   ; DX= PortA's adresse
mov al, 01Eh   ; 1Eh allows us to slide right
out dx,al      ; Send 1Eh to portA's outputs

mov dx,portB   ; DX= portB's adresse
mov al,01b     ; E=1 / RS=0 (inst)
out dx,al      ; Validation
mov al,00
out dx,al
ret
lcd_GTR endp



lcd_GTL proc
;==================

mov dx,portA   ; DX= PortA's adresse
mov al, 018h   ; 18h allows us to slide left
out dx,al      ; Send 18h to portA's outputs

mov dx,portB   ; DX= portB's adresse
mov al,01b     ; E=1 / RS=0 (inst)
out dx,al      ; Validation
mov al,00
out dx,al
ret
lcd_GTL endp






lcd_fir_line proc
;==================

mov dx,portA   ; DX= PortA's adresse
mov al, 080h   ; 80h allows us to select first line
out dx,al      ; Send 80h to portA's outputs

mov dx,portB   ; DX= portB's adresse
mov al,01b     ; E=1 / RS=0 (inst)
out dx,al      ; Validation
mov al,00
out dx,al
ret
lcd_fir_line endp





lcd_sec_line proc
;==================

mov dx,portA   ; DX= portA's adresse
mov al, 0c0h   ; c0h allows us to select second line
out dx,al      ; Send c0 to portA's outputs

mov dx,portB   ; DX= portB's adresse
mov al,01b     ; E=1 / RS=0
out dx,al      ; Validation
mov al,00
out dx,al
ret
lcd_sec_line endp




lcd_clearscreen proc
;==================

mov dx,portA   ; DX= portA's adresse
mov al, 01h    ;  01h force clear screen
out dx,al      ; validation


mov dx,portB   ; DX= portB's adresse
mov al,01b
out dx,al      ; Validation (instruction)
mov al,00
out dx,al
ret
lcd_clearscreen endp





lcd_init proc
;==================

mov dx,portB   ; DX= portB's adresse
mov al,00h     ; AL=00h

out dx,al      ; Enable=0 / RS=0

mov dx,portA   ; DX=portA's adresse
mov al,038h    ; AL= 38h
out dx,al      ; Send 38h to portA   (8bits/2lines mode)

mov dx,portB   ; DX= portB's adresse
mov al,01b     ; AL= 01b
out dx,al      ; E=1 / RS=0  Validation goes to instructions

mov al,0
out dx,al      ; E=0 / RS=0

mov dx,portA   ; DX=portA's adress
mov al,0Eh     ;
out dx,al      ; Send 0Eh to portA (cursor settings 0Ch:Vis - 0E:inv  0F:blkn)

mov dx,portB   ; DX=portB's adresse
mov al,01b     ;
out dx,al      ; E=1 / RS=0  Validation(instuction)

mov al,0
out dx,al      ; E=0 / RS=0


mov dx,portA   ; DX=portA's adresse
mov al,06h     ; cursor setup (deplacement) 06=move right
out dx,al      ; Send 06h to portA's output

mov dx,portB   ; DX=portB's adresse
mov al,01b
out dx,al      ; E=1 / RS=0  Validation

mov al,0
out dx,al
ret
lcd_init endp