Mechanical Pencil Calculator?

[Dave Britten]

Back in the mid '90s, I had a (very thick) pen that would flip open to reveal a little LCD inside the door, and a keyboard integrated into the pen body. It was a calculator and simple databank type of device, and the keys were so tiny that you were advised to use the end of the pocket clip on the cap as a stylus to push them! It was more of a novelty than anything genuinely practical.