Message Pads from the mid-90s including the fabulous Newton 2100.
On a whim, I popped in 4 AA batteries and hit the power switch… Brrrring, she came to life with the familiar Newton trill and even more amazing woke up with all her data intact. Yep; everything. All my calendar entries from 1997, my contacts, every application installed and working just fine and all my scribbled notes. All exactly the way I left it so many years. What a stunning example of elegant technology and engineering. Newton was flawed in many ways but in many others, no product on the market has ever matched her elegance, style and techno-wizardry.
Historical note; Newton shortly after its release was lampooned in a famous series ofDoonesbury cartoons which led to Steve Capps wife conspiring with Gary Trudeau to create the famous egg freckles Easter egg.