Although the original IRobot Roomba was the first commercially successful robot vacuum, it was not the first commercially available. The Electrolux Trilobite was released one year earlier in 2001, and while it was more advanced than the Roomba, the Roombas much lower price allowed it to win out.
The IRobot Roomba S9 is the oddest Roomba ever produced. It is the only IRobot model with a D shape instead of the circular shape every other Roomba has been. Unfortunately due to the odd shape, this model has a lot of parts only for the S9 itself, meaning that despite it only being one generation discontinued, it has the worst support of any of their robots parts wise (IRobot has already said they have stopped producing certain parts for it like wheel modules).
Despite the original IRobot Roomba releasing in 2002, the robot did not contain any hardware for self docking until 2004, with the release of the Roomba 4000/discovery series. The dock worked by shooting 2 ir beans in 2 different directions, allowing it to guide the roomba between them right to the base where it's charging pads make contact with the pins on the dock. Despite this design being almost 20 years old, modern Roomba docks work in almost the exact same way!
Since this place is completely dead, I'm gonna start posting daily Roomba facts until someone comes along and needs troubleshooting or something. Until then, enjoy all of the facts you would ever need to know about Roombas.
