You can just wrap your screen updates with a screenlock and screenunlock.
screen 18, 32
dim x as integer = 1
do
screenlock
cls
line(x, 200)-(x + 10, 210), RGB(255, 255, 255), BF
screenunlock
x += 1
if x > 630 then x = 1
sleep 20
loop until inkey <> ""
end
Looking forward to the tut MrP.