There are several ways to pass parameters to procedure, the easiest
way to pass parameters is by using registers, here is another example of a
procedure that receives two parameters in AL and BL registers, multiplies
these parameters and returns the result in AX register:
ORG 100h
MOV AL, 1
MOV BL, 2
CALL m2
CALL m2
CALL m2
CALL m2
RET ; return to operating system.
m2 PROC
MUL BL ; AX = AL * BL.
RET ; return to caller.
m2 ENDP
END