Agilent Technologies 54810A User's Quick Start Manual page 20

Setting Up the Oscilloscope
To attach the optional trackball
5 Connect the 9-pin "D" connector on the trackball cable to the COM1
port on the back panel. Tighten the retaining screws.
Figure 1-9
Connecting the Trackball Cable to the COM1 Port
For information on changing the trackball settings, see "To change the mouse
settings" in Chapter 3.
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