again hi! michael...thanks again and again...its my project in university...i read bible and another books but i confused...they say for using port as input load ff to it...ok! initially all ports ff
is this true

mov r4,#4h
start: mov a,p3
add a,r1
mov r1,a
djnz r4,start

is this program reads port3 4times and add the values?
or
mov r4,#4h
start: mov p3,#0ffh
mov a,p3
.
.
.
which one true.....