If I just plug my external SCSI CD drive into my Mac IIsi, and power em both up, I am unable to see the drive (I've given it a SCSI ID of 1)

The Drive has two SCSI sockets, but neither seem to work (are these just wired in parrallel?)

Is there some app that i need to 'mount' the drive etc?

Please excuse my ignorance, but I'm a complete Mac noob, and a PC semi Noob.

Regards

Mike