;NAME:- Chinmay M. Mule
;CLASS:-SE COMP II SHIFT
;ROLLNO:-34 PRN:-S18111044
;Assignment Name:-Write 80387 ALP to plot Sine Wave, Cosine Wave. Access
; video memory directly for plotting.



.387
.MODEL SMALL
.DATA
        X DW 1
        Y DW 0
        Xrad DQ ?
        D60 DW 60
        D100 DW 100
        D180 DW 180
        PIby180 DQ ?
        TAB DB 80H,40H,20H,10H,8H,4,2,1
        OFS DW 0

.CODE
START:  MOV AX,@DATA
        MOV DS,AX

        MOV AH,00               ;Set video mode
        MOV AL,06               ;Mode 6 i.e. 640 by 200 Graphics
        INT 10H

        FINIT
        FLDPI
        FIDIV D180
        FSTP PIby180
DRAWSINE:
        FILD X                  ;Load angle
        FLD PIby180             ;Convert to radian
        FMUL                    ;i.e. multiply by Pi/180
        FST Xrad
        FSIN                    ;Calculate sine
        FDIV Xrad
        FILD D60                ;Load amplitude
        FMUL                    ;Calculate Amplitude x sin
        FILD D100
        FSUBR
        FISTP Y

        CALL OFSCAL
        INC X                   ;Next angle
        CMP X,639                ;Last point on X axis
        JNE DRAWSINE            
EXIT:
        MOV AH,0
        INT 16H
        
        MOV AH,00               ;Set video mode
        MOV AL,02               ;Mode 2 i.e. 80 by 25 text
        INT 10H

        MOV AH,4CH
        INT 21H

OFSCAL PROC NEAR
        MOV AX,Y
        AND AX,1
        JZ L1
        MOV OFS,2000H
L1:     MOV AX,Y
        SHR AX,1
        MOV BX,50H
        MUL BX
        ADD OFS,AX
        MOV AX,X
        MOV CL,3
        SHR AX,CL
        ADD OFS,AX
        LEA BX,TAB
        MOV AX,X
        AND AX,07
        XLAT
        MOV BX,OFS
        MOV DX,0B800H
        MOV ES,DX
        OR ES:[BX],AL
        MOV OFS,0
        RET
OFSCAL ENDP
END START