Back in the days before the widespread adoption of smartphones, Palm was the market leader in PDAs. If you had one of those you’ll probably remember taking notes by writing those funky “Graffiti” characters and tapping your stylus onto, usually, a green monochrome screen. Some models even came with a battery-hungry backlight, but for the ultimate display experience you had to buy the Palm IIIc that came with a backlit full-colour display.
While revolutionary for its time, it was hampered by the technology available: the CCFL backlight took a second to start up, and even with the screen at full brightness it was rather dim by today’s standards. [TobleMiner] fixed these issues by designing a module to retrofit an LED backlight into your Palm IIIc.
The new backlight consists of a long, thin PCB designed to fit exactly where the CCFL tube sits. The PCB holds twenty-one white LEDs along with their current-limiting resistors to provide even illumination from top to bottom. A little MOSFET soldered onto the mainboard ensures the new backlight also correctly responds to the device’s “brightness” setting. [TobleMiner] recommends to remove the bulky CCFL transformer from the Palm’s mainboard to disable the corresponding circuitry and save a bit of weight.
The end result is understandably hard to capture on camera, but apparently gives the screen more vibrant colours. In any case, this might be a useful hack for anyone with a Palm IIIc with a broken backlight, though we can’t remember if that was a common issue. If you’re among those who still use original Palm devices, you might like this Palm-compatible Bluetooth keyboard. Don’t have a classic PDA? You can also run PalmOS on modern custom hardware.