LQ_DWORD_MUL    PROC    FAR

                ;Perform DX:AX = DX:AX * DI:CX

                MOV     BX,AX
                MOV     AX,DX
                MUL     AX,CX
                MOV     SI,AX
                MOV     AX,DI
                MUL     AX,BX
                ADD     SI,AX
                MOV     AX,CX
                MUL     AX,BX
                ADD     DX,SI
                RET

LQ_DWORD_MUL    ENDP

LQ_DWORD_DIV    PROC    FAR

                ;Perform DX:AX = DX:AX / DI:CX

                OR      DI,DI
                JNE     label_2
                CMP     CX,DX
                JBE     label_1
                DIV     AX,CX
                XOR     SI,SI
                MOV     DI,DX
                XOR     DX,DX
                RET
label_1:        MOV     DI,AX
                MOV     AX,DX
                XOR     DX,DX
                DIV     AX,CX
                XCHG    AX,DI
                DIV     AX,CX
                XCHG    DX,DI
                XOR     SI,SI
                RET
label_2:        PUSH    BP
                MOV     BP,CX
                MOV     BX,DI
                XOR     SI,SI
                MOV     DI,SI
                MOV     CX,10H
label_3:        SAL     DI,1H
                RCL     SI,1H
                SAL     AX,1H
                RCL     DX,1H
                ADC     DI,0H
                SUB     DI,BP
                SBB     SI,BX
                INC     AX
                JAE     label_4
                ADD     DI,BP
                ADC     SI,BX
                DEC     AX
label_4:        LOOP    label_3
                POP     BP
                RET