Picture Comments

This picture shows the front panel of an Acer CD-Rom drive. Not all cd rom drives have these controls, however there are many makes that do. Mitsubishi (Diamond Mitsubishi), Acer, Aopen, Lite on (some models), Toshiba (some models), Early Creative CD-Rom Drives, Early Panasonic Drives (Panasonic have an analogue volume control). Be careful in choosing the drive you want to use as some Cd-Rom drives will not do anything unless they are connected to an IDE controller (normally found on a PC main board)

After carefully opening the cd-rom housing, and carefully disconnecting the ribbon cables that attach it to the motor assembly. You will see something similar to this. Clearly you can see the headphone jack and the volume up / down controls. We wont be soldering to this side of the board. The picture here, is to give you an idea of what you should see.
 This picture shows the underside of the Cd-Rom drive controller board. As you can see there are 3 connections to be made. Left / Right Audio and Ground. Using shielded audio cable connect solder to the solder pads and run the lead out through the rear of the cd-rom drive case. Ensure you use a fine tipped soldering iron, and quickly make the connections. Some of these tracks and solder pads are very thin and will lift from the board if too much heat is applied.
All the switches on the Acer connect across 2 solder pads. The picture here shows 2 switches. You can see that they are common grounded on the Acer. It should be similar on most models. Each pad will have one wire connected to it. The large area of green with grey dots is the ground plane. Solder one wire to the ground plane for each switch.

Solder one wire to each of the isolated solder pads (ie the ones that  are not connected to the ground plane)

This pic shows the top of the board again. Typically these are the controls you should find on the board (see the black areas towards the top of the board)
You  could use the existing 40 pin cable connector to attach a ribbon cable to the controls. To do this, you need to do the following:

1: Carefully cut the connector's pins that you want to use. Leave enough of the pin available to be able to solder a wire too.
2: Bring the wires you have attached to the controls, to the back of the cd rom drive. Make sure you lay them flat (remember you will have to put the top back on the drive when you are finished).
3: Place some heatshrink tubing or spaghetti over the wire before you solder to the connector.
4: Solder the wire to the connector
5: Slide the heatshrink tubing over the connection and gently heat ( this will stop the wires shorting on the drive case, and also protects against wires working loose due to vibration).

If you use this method of connection you will need to get a 40 pin IDE plug and cable, long enough to reach the front panel of your B9.

Also remember that the pins will not be sequential on the connector. ie your connections will be on 1 3 5 ect, not 1234... of course this would depend on which end of the connector you start with.

All that is left is to run the audio out to your amplifier and the control wires off to switches behind the B9's teeth lights. Jeff B has a good description for making the switch panel. Make sure you use momentary contact switches and not latching switches....
Finally, you will need to connect the cd rom drive to a power source. Most people are using 12 volt power systems, so you will need a regulated 5 volt dc source for the power.  I will post a circuit diagram for a small regulator that can handle the cd rom drive, soon.