[Jan Olligs]

I am not the programmer on my team and I have never worked with BASIC stamps, just with Atmel AVRs, which are programmed in assembler, but most microcontrollers have a similar syntax, so here is my explanation:
On microcontrollers, most of the ports (except, for example, for the analog ones) can be either input or output. To tell the controller how you would like to access the port, whether as input or output, you have to define it in teh initialization statements. This can obviously be done by writing 'Output' followed by the port number. From there on, you cann access it by the internal aliases out[port number].
Take this as a temporay help, I bet that someone who knows the BASIC Stamp really well is going to post a reply sometime later this day.
Good luck!