This is one of the original methods for hooking a keyboard up to use as a MIDI device. To do this you will need a Wave Table sound-card, a universal MIDI adapter cable that is compatible with a joystick port, a MIDI compatible Casio keyboard or other device, an 8-to-ten-foot MIDI cable, some speakers and sequencing software. You will need software and speakers for all of the following methods.
On the back of the sound card you will see three 1/8-inch inputs and a serial joystick port. If your speakers already have an 1/8-inch line, plug them into the line out port on the sound-card. It is usually a green 1/8-inch port. If your speakers are RCA or 1/4-inch, you can get an adapter at your local electronics store. To hook up your MIDI controller up to the sound card, you need a universal MIDI connector with a 15-pin D-plug on one end (looks like a serial port connector) and a 5-pin OUT MIDI connector and 5-pin IN MIDI connector on the other. These cables are widely available at electronics and computer stores. Mark the MIDI OUT connector because we will not be using it. Plug the long MIDI cable into the OUT port on the back of your keyboard and the other end into the IN port on the MIDI adapter. On Casios these ports are usually right in the middle of the keyboard. The keyboard is now physically ready to be used. Open up your sequencing software and configure it to recognize the newly connected device.
MIDI can also be connected via USB. To do this, you need a MIDI cable with a USB connector on one end and MIDI IN and MIDI OUT connectors on the other end. Plug the MIDI connectors into the respective IN and OUT ports on the back of your device and plug the USB connector into an open USB slot on your computer. Open the software you are using and configure it to recognize your device and you are ready to record and perform. Newer devices, usually specifically designed for MIDI, will have USB ports installed in them and in that case all you need is a strait USB cable to hook up the device. This is the case for Casio models LK-220 and the CTK-710. For your Casio you will need to be sure you have the Casio USB midi driver installed on your system.
If you are using your Casio for more serious applications you may purchase a sound card with built-in MIDI capabilities. This will achieve the greatest MIDI quality possible. If you have a MIDI-capable sound card, all you need is a MIDI to MIDI cable to connect your keyboard or other device to the sound-card. In most cases, the sound card will come with the cable. If you are serious about making MIDI music Casio has a Casio Music Site with all sorts of MIDI resources.