SID/STAR Question

Purchased the 777 recently (now that I've got a system that will cope with Fly 2's rather demanding nature) and I'm having a real blast. What an amazing learning experience it is. I'd say it's about 3-4 times more complex than the Fly! 757-200.A little question about SID/STARS though: I can't figure out whether the FMC will automatically adhere to altitude restrictions at the waypoints, or will these altitudes have to be set via the MCP? The manual suggests that the FMC adheres to these 'immediately', but I thought the FMC was effectively governed by what's dialed into the MCP window. Just a little query I was curious about...Jim TrimbeeP.S. this plane has all but ruined FS2002 for me now!