For anyone that doesn't know if you want to checkout Lucas Arts 1st game Maniac Mansion. Grab a copy of the later released sequel "Day of the Tentacle". (Which I picked up yesterday on cd with Sam and Max for $20 [thats about $10 US])
In the professor's mansion in present day go upstairs to the top floor, enter the room on the right and use the computer. On their is the fully working original version of Maniac Mansion. Complete with PC speaker 80's rock! Worth a look anyway.