About the Special Features
PC
Headphone Jack 
Serial Por Volume Control
Your BOOKMAN 580 model is equipped with several special features that many, but not all, BOOKMAN books use. To learn if you can use the special features with a particular book, read its User’s Guide.
Serial Port: The serial port allows your BOOKMAN, when connected by Franklin’s 3.5 mm serial cable, to transfer information to and from a personal computer.
Warning: Using a serial cable other than the one obtained from Franklin may damage your BOOK-
MAN and/or PC. Franklin’s serial cable is specifically designed for the transfer of data between your BOOKMAN and a PC.
Note: Speak English! does not use the serial port.
Volume Control: The dial located under the headphone jack controls the volume of the headphones.
Headphone Jack: Your BOOK- MAN also has a 3.5 mm stereo headphone jack for use with a standard impedance 8 Ohm headphones.
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