What is a RS232 Serial Port and how do I know if I have one? :0

[Allah]

A rs232 serial port is Apple's version of a serial port. It's what you plug your printer/modem into.
If you have iMac, BW G3 or a G4 you don't. All the other beige Macs including the beige G3s have them

[jeromep]

I think a better way to describe this is as such. RS-232 is miniDIN-8 or described physically; a small round port that has 8 pins in it. The previous answer is correct, any of the newer Macs do not have any classic Mac serial capabilities; they have USB.

Simple answer RS-232 means you have a round 8-pin connector.

[Walter J. Ferstl]

Actually, on most PowerBooks (up to the G3 Wallstreet series) you have just one of these serial ports (modem and printer port combined into one socket), on beige Macs up to G3 you have two of these ports.

The printer port with these Macs is not exactly a RS-232, but a RS-422 port usable for Appletalk networking, too. But a RS-422 can do anything a RS-232 can, it is just more capable.

In some situations to use the printer port as a plain RS-232 (e.g., for connecting a modem) you need to turn AppleTalk off.

Walter.