The IRDA
On an iMac was for transfering files between a Powerbook and an iMac. Those first rev. A & rev. B (did rev. C have an IRDA port?) didn't have airport so that was a cheap and simple means of transfering small documents between the two.
Something was up with the rev. D because it didn't include an infrared port. But the reason it didn't appeared later under the name of "airport".
On an iMac was for transfering files between a Powerbook and an iMac. Those first rev. A & rev. B (did rev. C have an IRDA port?) didn't have airport so that was a cheap and simple means of transfering small documents between the two.
Something was up with the rev. D because it didn't include an infrared port. But the reason it didn't appeared later under the name of "airport".