Hello Mika,

M>>MAIN:
LOW GPIO.0
SLEEP 1
HIGH GPIO.0
SLEEP 1
GOTO MAIN
END
<<

You need to go to the data sheet...
You have not set your pins to all output.
You have not turned off your comparitor.

TRISIO=%00000000 SEtting your pins to output ((not digital))
eventhough HIGH and LOW automatically set your pins to outputs, I have a habit of doing it anyhow...Because I use the value of 1 and 0.
CMCON0=7 turning off the comparitors

Instead of sleep, I would use Pause 500.

See this thread:
http://www.picbasic.co.uk/forum/show...light=blink%2A

Dwayne