The PowerBook Duo was a small yet powerful little laptop. It came in many different models. The PowerBook Duo would slide into a Duo Dock for expandability. Although small for on the go, the PowerBook Duo lacked ports such as ADB, monitor, SCSI, PC card slot, and floppy drives when not plugged into the bulky docking station. Later though, Apple did introduce a mini-dock which was a BIG improvement. However, by the time it was introduced, the PowerBook Duo was seeing its last days of Mac glory.