Hi -
The previous post is correct - in your note however you did not mention if you have an accelerator in your A1200, which brand, etc. My machine for example I have a GVP 1230 accelerator with the SCSI adapter. There is a break out hole on the back of the machine where the new SCSI connector would pop-out. You have to install the correct SCSI driver (mine is GVPSCSI device or some such thing)
and away you go.
The Squirl PCMCIA adapter is a good option also. If you could find the IDE-fix adapter for the IDE header inside the unit you could add a regular ATAPI CD rom device in an external case. This is a nifty way to go also. I saw two IDE fix gizmos for sale on E-Bay. Software Hut sells them also.