When a Wyse 60 terminal in PC-TERM (scancode) mode is connected via a serial line that is also in scancode mode, if you press any of the keys that generate <Esc> sequences (for example, <Ins>, <Home>, <Left Arrow>) the terminal and the system will repeatedly send the sequence backwards and forwards. This fills the input buffer, making the terminal unusable until you log off the system, or until you set the serial line using the command stty -echo.