When a computer/turtle starts running code, ComputerCraft starts a ten second timer. If that code doesn't yield before that timer ends then ComputerCraft will either crash the script or the whole computer (depending on the nature of the functions your script is calling). After each yield, any other systems waiting to run code may do so, then after they've all yielded, processing continues with a new time limit.
The reason why is that running your code chews up valuable server processing power, and so it shouldn't be able to monopolise it. In fact, only ONE CC device can run code at a time: While one is doing something, none of the others can do anything until it yields.
Whether or not it takes more than ten seconds for your code to execute has a little to do with the power of the Minecraft server it's running on, and a lot to do with how often you allow your code to yield. Pulling events (eg getting typed characters or checking timers) triggers a yield, and many commands (eg turtle movements, sleeping, or getting text input from the user) have to pull events to work anyway. Basically, anything that triggers a pause is pulling an event in order to do it, and in order to pull an event the code yields.
In your code, these loops here are your problem:
while true do
local tWidth = width
while true do
local temp = string.sub(text, done, tWidth)
if string.sub(temp, #temp) == " " then
temp = string.sub(text, done, tWidth - 1)
table.insert(lines, temp)
done = tWidth + 1
else
tWidth = tWidth - 1
end
end
end
They never yield, and they also never stop - there's no way the code underneath them will ever run.
It looks like you were perhaps trying to take every word in "text", and place them sequentially into a table? If so, you could replace the whole thing with:
for word in string.gmatch(text, "%w+") do lines[#lines + 1] = word end
