A PCMCIA sized pda now owned by Xircom.

It has very limited input (kind of like how you enter a name in console games). It has only the standard apps. There is no facility for downloading new apps. The Rex Pro has 512k of ram.

It's indeering quality is its size. It can be synced to your laptop by sliding it in to the pcmcia slot, or sliding it into a special cradle for desktop pcs.

With the purchase of Xircom by Intel in 2001 the Rex seems to have completely disappeared.