Serial cables come in different flavors. The most common type of serial cable comes with DB-9 connectors. Older serial cables may come with DB-25 connectors.

If you have purchased a serial cable that will not connect to either your PC or a peripheral device, you may need to purchase an adapter to convert your cable from 9 pin to 25 pin or vice versa.

When buying a serial cable make sure your it is a full-flow serial cable. This means that all the pins on both sides of the cable are connected. Cheaper cables do not connect all the pins.