Apple Power Macintosh 7500 Series - Manual (Page 59)

S-video connectors
The S-video connector is a round plug with several small metal pins. You
can plug this type of connector into your computer’s S-video input port.
IMPORTANT The S-video connector resembles other Macintosh connectors,
such as those for a printer, modem, mouse, or keyboard. Don’t confuse the
connectors; they’re not interchangeable.
Composite video connectors
Many video devices use composite video format instead of S-video. The
cables for these devices have RCA-type connectors (plugs).
RCA-type plug
S-video connector
49 Connecting Additional Equipment