chat.asm

public CHAT_MAIN
extrn tryagainDashboard:FAR
extrn MAINGAMEDASH:FAR
ClearUpperScreen MACRO
    mov ax,060Dh
    mov bh,09h
    mov cx,0       
    mov dh, 12
    mov dl, 79
    int 10h 
    
ENDM ClearUpperScreen

ClearLowerScreen MACRO
    mov ax,060Ch
    mov bh,30h
    mov ch,13
    mov cl, 0       
    mov dh,24
    mov dl, 79
    int 10h 
    
ENDM ClearLowerScreen

SCROLL_UPPER_SCREEN MACRO
    mov ah, 6
    mov al, 1
    mov bh, 9h
    mov ch, 0
    mov cl, 0
    mov dh, 12
    mov dl, 79
    int 10h
ENDM SCROLL_UPPER_SCREEN

SCROLL_LOWER_SCREEN MACRO
    mov ah, 6
    mov al, 1
    mov bh, 30h
    mov ch, 13
    mov cl, 0
    mov dh, 24
    mov dl, 79
    int 10h
ENDM SCROLL_LOWER_SCREEN



SaveCursorS MACRO
    mov ah, 3h
    mov bh, 0h
    int 10h
    mov XposS, DL
    mov YposS, DH
ENDM SaveCursorS

SaveCursorR MACRO
    mov ah, 3h
    mov bh, 0h
    int 10h
    mov XposR, DL
    mov YposR, DH
ENDM SaveCursorR

SetCursor MACRO x, y
    mov ah, 2
    mov bh, 0
    mov dl, x
    mov dh, y
    int 10h
ENDM SetCursor


.MODEL small
.STACK 100h
.data
	VALUE DB ?
	XposS DB 0
	YposS DB 0
	XposR DB 0
	YposR DB 0Dh

.code

CHAT_MAIN proc
	            mov                 ax, @data
	            mov                 ds, ax

   

	; initinalize COM
	;Set Divisor Latch Access Bit
	            mov                 dx,3fbh       	; Line Control Register
	            mov                 al,10000000b  	;Set Divisor Latch Access Bit
	            out                 dx,al         	;Out it
	;Set LSB byte of the Baud Rate Divisor Latch register.
	            mov                 dx,3f8h
	            mov                 al,0ch
	            out                 dx,al

	;Set MSB byte of the Baud Rate Divisor Latch register.
	            mov                 dx,3f9h
	            mov                 al,00h
	            out                 dx,al

	;Set port configuration
	            mov                 dx,3fbh
	            mov                 al,00011011b
	            out                 dx,al


	CLEARSCREEN:

	            ClearUpperScreen
	            ClearLowerScreen
	            SetCursor           0, 0

	            call                detect

detect proc

	START:      

	;Check that Transmitter Holding Register is Empty
	            mov                 ah,01h        	; check if key is pressed
	            Int                 16h
	            jz                  dummy2        	; if no key is pressed go check for uart again
	            jnz                 send

	send:       
	            mov                 ah,0h         	;read the char to see if it is esc
	            Int                 16h

	            mov                 VALUE, AL
	            cmp                 al, 0Dh
	            jz                  ENTERKEY
	            jnz                 CONT

	dummy2:     jmp                 recieve

	ENTERKEY:   
	            cmp                 YposS, 11
	            jz                  OverFlow
	            jnz                 INCREMENT
        
	OverFlow:   
	            SCROLL_UPPER_SCREEN
	            jmp                 PRINT

	INCREMENT:  
	            inc                 YposS
	            MOV                 XposS, 0

	CONT:       
	            SetCursor           XposS, YposS
	            cmp                 XposS, 79
	            jz                  CHECKY
	            jnz                 PRINT

	CHECKY:     
	            cmp                 YposS, 12
	            jnz                 PRINT
	            SCROLL_UPPER_SCREEN
	            mov                 XposS, 0
	            mov                 YposS, 12
	            SetCursor           XposS, YposS

	PRINT:      
	            mov                 ah, 2
	            mov                 dl, VALUE
	            int                 21h


	SENDSTATUS: 
	            mov                 dx , 3FDH     	; Line Status Register
	AGAIN:      
	            In                  al , dx       	;Read Line Status
	            AND                 al , 00100000b
	            JZ                  recieve


	;If empty put the VALUE in Transmit data register
	            mov                 dx , 3F8H     	; Transmit data register
	            mov                 al, VALUE
	            out                 dx , al

	ESCAPEKEY:  
	            cmp                 al, 1Bh
	            JZ                  dummy
	            SaveCursorS
	            jmp                 START

	dummy:      jmp                 exit
	dummy3:     jmp                 send

	recieve:    
	            mov                 ah, 1
	            int                 16h
	            jnz                 dummy3

	;Check that Data Ready from UART
	READSTATUS: 
	            mov                 dx , 3FDH     	; Line Status Register
	            in                  al , dx
	            AND                 al , 1
	            JZ                  recieve       	; if there is not char in uart go check for key pressed

	READ:       
	            mov                 dx , 03F8H
	            in                  al , dx
	            mov                 VALUE , al
	            cmp                 VALUE, 1Bh
	            jz                  dummy

	            cmp                 VALUE, 0Dh
	            jnz                 contR
	            jz                  newlineR

	newlineR:   
	            cmp                 yposR, 24
	            jz                  XR
	            jnz                 YR

	XR:         
	            SCROLL_LOWER_SCREEN
	            jmp                 PRINTR


	YR:         
	            inc                 YposR
	            mov                 XposR, 0

	contR:      
	            SetCursor           XposR, YposR
	            cmp                 XposR, 79
	            jz                  CHECKYR
	            jnz                 PRINTR

	CHECKYR:    
	            cmp                 YposR, 24
	            jnz                 PRINTR
	            SCROLL_LOWER_SCREEN
	            mov                 XposR, 0
	            mov                 YposR, 24
	            SetCursor           XposR, yposR

	PRINTR:     
	            mov                 ah, 2
	            mov                 dl, VALUE
	            int                 21h

	            SaveCursorR

	            jmp                 START
   
detect endp

	exit:       
	; mov ah, 4ch
	; int 21h
	            call                MAINGAMEDASH

CHAT_MAIN endp
end CHAT_MAIN