INCLUDE "MACROS.TXT"

STACK SEGMENT
    X0 DW 0
    Y0 DW 0
    X1 DW 0
    Y1 DW 0
STACK ENDS

DATA SEGMENT
    MS1 DB "1st number:",'$'
    MS2 DB "2nd number:",'$'
    MS3 DB "Result:",'$'
    MS4 DB 0AH,0DH,'$'
DATA ENDS

CODE SEGMENT
    ASSUME CS:CODE, DS:DATA, SS:STACK

PRINT_HEX PROC NEAR
    CMP DH, 9           ;Elegxoume an einai noumero
    JG ADDRS1           ;An oxi einai gramma
    ADD DH, 30H         ;An nai, prosthetoume to 30h
    JMP ADDRS2
ADDRS1:
    ADD DH, 37H         ;An einai gramma prosthetoume to 37h
ADDRS2:
    PRINT DH            ;Tipwnoume
    RET
PRINT_HEX ENDP

PRINT_HEX1 PROC NEAR    ;Tiponoume to periexomeno tou DH
    AND DH,0F0H         ;ana 4 bit
    RCR DH, 4
    CALL PRINT_HEX
    MOV DX, X0
    AND DH, 0FH
    CALL PRINT_HEX
    MOV DX,X0
    SAL DX,8
    AND DH,0F0H
    RCR DH,4
    CALL PRINT_HEX
    MOV DX,X0
    SAL DX,8
    AND DH, 0FH
    CALL PRINT_HEX
    RET
PRINT_HEX1 ENDP

READ_4B PROC NEAR       ;Routina gia na diavazei 4 byte
    MOV CX,4
    MOV BX,0
READ1:
    SAL BX,4
    CALL HEX_KEYB
    MOV AH,0
    ADD BX,AX
    LOOP READ1
    RET
READ_4B ENDP

HEX_KEYB PROC NEAR      ;Routina gia anagnwsi enos hex psifiou
    PUSH DX
IGNORE:
    READ
    CMP AL,30H          ;Elegxos ean einai egkyro noumero
    JL IGNORE
    CMP AL,39H
    JG ADDR1
    PUSH AX
    PRINT AL            ;Ean einai, to emfanizoume stin othoni
    POP AX
    SUB AX,30H          ;kai to metatrepoume apo ASCII
    JMP ADDR2
ADDR1:
    CMP AL,'A'          ;Elegxos ean einai egkyro gramma
    JL IGNORE
    CMP AL,'F'
    JG IGNORE           ;Ean oxi, to agnooume
    PUSH AX
    PRINT AL            ;Emfanisi
    POP AX
    SUB AX,37H          ;Metatropi apo ASCII
ADDR2:
    POP DX
    RET
HEX_KEYB ENDP

MAIN PROC FAR
    MOV AX,DATA
    MOV DS,AX
START:
    PRINT_STR MS1
    CALL READ_4B        ;Diavazoume ta prwta 4 bytes
    MOV X1,BX           ;ta apothikeuoume sti stoiva
    CALL READ_4B        ;kai antistoixa ta epomena 4
    MOV X0,BX
    PRINT_STR MS4
    PRINT_STR MS2
    CALL READ_4B        ;Kanoume ta idia kai gia to deutero
    MOV Y1,BX           ;noumero
    CALL READ_4B
    MOV Y0,BX
    PRINT_STR MS4
    PRINT_STR MS3
MULT1:
    MOV AX,X0           ;X0 x Y0
    MUL Y0
    MOV BX,DX           ;ston BX vazoume tin MSW
    MOV CX,AX           ;kai ston CX ti LSW
MULT2:
    MOV AX,X0           ;X0 x Y1
    MUL Y1
    ADD BX,AX           ;prosthetoume tin LSW stin proigoumeni MSW
    MOV X0,DX           ;apothikeuoume tin MSW
MULT3:
    MOV AX,X1           ;X1 x Y0
    MUL Y0
    ADD AX,BX           ;prosthetoume tin LSW stin proigoumeni
    MOV BX,AX
    ADC DX,X0           ;to idio me tis MSW
    MOV X0,DX
MULT4:
    MOV AX,X1           ;X1 x Y1
    MUL Y1
    ADD AX,X0           ;prosthetw tin LSW stis MSW apo prin
    ADC DX,0
    MOV X0,DX
    PUSH AX
    MOV DX, X0
    AND DH, 0FH
    CALL PRINT_HEX
    MOV DX,X0
    SAL DX,8
    AND DH,0F0H
    RCR DH,4
    CALL PRINT_HEX
    MOV DX,X0
    SAL DX,8
    AND DH, 0FH
    CALL PRINT_HEX
    POP AX
    MOV X0,AX
    MOV DX,X0
    CALL PRINT_HEX1
    MOV X0,BX
    MOV DX,X0
    CALL PRINT_HEX1
    MOV X0,CX
    MOV DX,X0
    CALL PRINT_HEX1
    PRINT_STR MS4
    EXIT
CODE ENDS
END MAIN