Michael Horne's Raspberry Pi-Powered Portable Cyberdeck Boasts a Classic Psion Series 5 Keyboard

Developer Michael Horne has performed a Nintendo 2DS-like transformation on a damaged Psion Series 5 palmtop, creating a flat-layout Raspberry Pi-powered portable that reuses Psion's iconic compact yet surprisingly comfortable keyboard.

"I was recently selling some HP Jornada PDAs [Personal Digital Assistants] on eBay, having spectacularly failed to get them online via a Wi-Fi PCMCIA card," Horne explains of the project's inspiration. "What I really wanted, I decided, was a Raspberry Pi in a compact 'Cyberdeck style' unit. I did look at converting one of the Jornada 680s that I had as the keyboard was, if a bit small, adequate for my needs. I looked for a converter of some kind to take the ribbon cable used by the Jornada’s keyboard to a USB output, but I looked in vain, hence the decision to subsequently send them to eBay."

While searching, Horne came across an adapter designed by Rasmus Backman, which took the keyboard from a classic Psion Series 5 palmtop — famous for being installed with a clever hinge mechanism that pushes the keyboard out as the screen swings up in order to provide the highest typing comfort in the smallest closed footprint — and fed it through a Microchip ATmega32U microcontroller, switched out for a Raspberry Pi RP2040 in a later redesign, to convert it to USB for use with modern machines, including a Raspberry Pi single-board computer.

Horne's initial efforts focused on creating a clamshell-style foldable inspired by the Jornada and Series 5 in their original incarnations — but that proved a little challenging, in particular when it came to routing the ribbon cables for power and keyboard across the hinged section. A quick re-think delivered an alternative design, which bore the same relation to the original as Nintendo's 2DS does to the 3DS: an abandoning of the clamshell concept in favor of a fixed flat casing, keyboard positioned below the screen.

Inside the housing is a Raspberry Pi 4 Model B single-board computer, replacing a less-powerful Raspberry Pi 3 Model A+ in earlier designs, along with a Waveshare UPS 3S power supply linked to three 18650-format batteries. "Marvelously, the 3S UPS board comes with a button to turn it on and also a barrel jack charging port," Horne notes. "I also, following a suggestion from a friend, added a 'handle' to the top part of the box (which was now in two halves for easier re-printing!) giving the whole thing the look and feel of a 1980’s Speak and Spell!"

The full project is documented on Horne's website; the maker says he'd "like to open source all the designs for the case," but is waiting until a few final tweaks have been completed.