The IBM 5291 Display Station Keyboard was the earliest terminal Model F variant in production. The so-called "bigfoot" Model F uses the same keyboard assembly early IBM 5150 PC Keyboards used albeit lacking the controller that generates set 1 scancodes, meaning bigfoot Model Fs are essentially brainless on their own. The 5291 itself is a low-cost successor to the IBM 5251 Display Station, meaning the bigfoot Model F also takes on the 5251's functional layout. Stylistically, the keyboard has much in common with the IBM 5324 Floortop Keyboard (thus both resemble a Model F/XT with larger bezels) albeit the 5291 keyboard is slightly smaller but features the three-setting adjustable feet (larger than any other IBM keyboard feet) this keyboard is known for.