Heiramus

Maybe you can try something like this:

function listen()
event.ignore("modem_message",listen)
-- Do your thing
event.listen("modem_message",listen)
end

Please check out the wiki before posting here.

WIKI

I had a look and this is what i found.

General stuff:

http://ocdoc.cil.li/component

http://ocdoc.cil.li/api

How to controll the robot

http://ocdoc.cil.li/api:robot

How to arrange items in an inventory

http://ocdoc.cil.li/component:inventory_controller

You should also look for some lua tutorials if you are not familiar with it.

you only need 1 gpu

bind your gpu to the first screen then use "io.write" to write "Computer Lab"

Then bind it to the second screen.

If you want to write a message to the first screen just bind the gpu to the first screen again.

If you need to use 2 gpus then do the following.

component = require("component")
component.setPrimary("gpu","your gpu address")

then just use io.write()