Hello Max,
According to the chat I had with Paul from atlantic
systems, it's an eprom chip that has to be replaced. Eproms can
be programmed with an eprom programmer but only erased with a UV
lamp. So no cd-rom upgrade. The good news is that it's
still available for under $90 (Yikes!)
Even got the part number (8341141) if you want to give it a shot.
Marc