How do people get the logos & stuff on a monitor?

I noticed on youtube people have their computers when they start up they have a symbol or logo on it.

Here's what i mean
theres a cup of coffee sort of shape on the monitor, how to accomplish it?
At 0:16
http://www.youtube.com/watch?v=M4tpwi53Zxs&feature=BFa&list=PL4EE50FD68A1E3AFF

1) Write the text to the monitor
2) Err… I think that's it :)/>/>

What is exactly the part that you have troubles with?

Like, When i try, they never like form into text, I was trying to write Yogscast

You've just got to line it up right so that it appears correctly. Trial and error is probably your best bet when trying to make ASCII art.

Since I didn't want to make a new post, how do you change the size of the text?