Apple Macintosh Performa 5400 Series - Manual (Page 8)

2 Plug the keyboard cable into the ADB port marked with the
◊
icon on the back of the
computer.
If you use a second monitor in addition to the one built into your computer, it
may also have a port to which you can connect the keyboard or mouse. See
the information that came with the monitor.
3 If you want to adjust the keyboard angle, lower the feet on the keyboard.
To adjust the keyboard angle, lower the feet until they snap into position.
V ADB port
7 Getting Started