That is what the cabling should look like after installing the NickLock (of course the IDE and power cables are still missing).

Choosing The Hard Drive

The key switch has three different positions: Left, right and middle. This picture shows the key at middle position, which causes neither of the drives to be accessible to the system, effectively creating a lock. If you switch the key to left position, it selects the drive on the left by having its cable close its master jumper.

Although it might have been useful to include a setting that lets you choose both drives, there is probably a good reason why NickLock only allows you to select between single drives or none. For one thing, only a few drives run as slave by default if no jumper mode is set. The majority of drives run in single or master mode by default, and if you use two of them, there is no way to assign the specific drives to master or slave, thus causing a conflict.