Apple Macintosh Performa 6400 Series - Manual (Page 11)

You can use any standard phone cord to connect your internal modem
connector to a phone jack. If you have only one phone jack, consider
purchasing a line splitter at an electronics supply store. A line splitter enables
you to plug your phone and your modem into the same jack at the same time.
Keep in mind that when your phone and your modem share a single phone
line, you will not be able to use both pieces of equipment at the same time,
even if they are attached to separate phone jacks. While you use your modem,
outside callers will get a busy signal and you cannot call out. When your
phone is in use, you cannot use the modem. (By the way, you can keep your
answering machine connected to your phone, even if your phone and modem
share the same telephone line.)
IMPORTANT During lightning storms, disconnect your modem by unplugging its
phone cord from the phone jack. This helps avoid accidental voltage overload.
Internal modem connector Phone cord
Phone jack in wall
To telephone
Line splitter (purchased separately)
To internal modem
External modem port
(This port is covered
if an internal modem is
installed. If it is covered,
do not remove the cover
or plug anything into the
external modem port.)
11 Getting Started