Beginning in 1995 with the PowerBook 190 and 5300 models, Apple laptops shipped with an expansion bay for both Apple and third-party drives. The drives were “hot-swappable,” meaning that the user could pull out one drive and replace it with another without restarting the laptop.
This PowerBook Floppy Drive Expansion Bay Module from 1996 works with PowerBook 1400-series laptops.
