Digital touch Screen Combination lock

[richard]

make lesson 1 loop like this and try with and without the nop

loopy:
lata=2
pause 10
porta.1 = 0
;@ nop
porta.0 = 1




pause 1000
 
goto loopy

the secret is that leds when forward biased charge up , when you set them low the charge can hold the pin high long enough
to trigger a rmw event on a fast chip. the nop allows enough time for the charge to dissipate {62 nano seconds}