Before DVD-ROM and CD-ROM, the only way to install software was with floppy disks. But what if the software was too big to fit on one 1.4MB floppy? The installer application would piece together a sequence of small "tomes" of data from multiple disks, a process which required the user to insert the next disk when the previous one was ejected. This was easy enough, but sometimes a funny thing would happen. A disk would eject, and the Mac would prompt for the next disk. Once that disk had been accessed, it would eject, and the Mac would ask for the first disk. Then the next disk, then the first disk, then the next disk, then the first disk. This would go on ad infinitum, or until a frustrated user decided to pull the plug on his installation. Maybe this is how Apple got the idea for their address, 1 Infinite Loop?