Wiring An SD Card To A Handspring PDA’s 68K Bus With Only Three SOT23s

In 1998 the founders of Palm had a bit of a falling out with the wildly successful PDA company’s new owners. They set up a new company called Handspring, which enabled them to make PDAs again in the way they preferred, This resulted in the Handspring Visor line of PDAs, which featured a big cartridge slot called the Springboard Expansion slot. Much like a Gameboy, you could put in a range of modules, ranging from games to cameras to memory expansion and more. Since these modules connect directly to the internal Motorola 68k-based microprocessor, you could make a module either to comply with this standard or if you’re like [Dmitry], you’d figure out a way to get an SPI device like an SD card to communicate and expand storage.

Editor note: Dmitry’s design isn’t the first SD/MMC interface for the Visor. Portable Innovation Technology’s SD MemPlug Module supported SD/MMC way back in 2002. However – MemPlug was a commercial product, while Dmitry’s work is open source.

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Give Aging Technology A Chance

Robot Arm with PDA Brain

In our rush to develop new projects, a lot of the time we jump the gun and order new Arduinos and microprocessors, when with a bit of ingenuity you can recycle old tech for new purposes. [Eric Wiemers] has a Lynxmotion robot arm and needed a way to control it — sure he could use an Arduino or something… or he could try to make use of his trusty PDA that never left his side, well, 10 years ago anyway!

In 2001, Handspring released the Visor Neo — an affordable PDA competitor to the Palm Pilot. It had a super fast 33MHz processor, a whole 8MB of RAM and a 16 bit grayscale screen with a whopping 160 x 160 pixels. [Eric] was lucky enough to get his hands on one a year after it came out. Fast forward today and PDA’s are pretty much obsolete due to smart phones — but [Eric] didn’t want to just chuck it, it still worked after all!

At first he thought of just practicing coding and writing some apps for it — but let’s be honest, he’d never use it instead of his smart phone. He dug a bit deeper and discovered it was actually capable of serial output — this realization opened up a world of possibilities! Using a spare charging cradle, he tapped into the serial connections and added a Molex connector to allow him to hook it up to his Lynxmotion. He wrote his own control app with a GUI which means he can now control the robot arm without needing to drag around his laptop — success!

Think twice before throwing out your old tech. Perhaps that disused piece of junk can have a second chance in your next DIY project.