Here’s a 64KB Commodore PDA system that runs BASIC. Tight!
Here are a few pics of my own DTV Hummer project. I had an old PSOne LCD screen lying around and I thought I’d make a C64 laptop. Actually, it’s more like a C64 PDA! It measures 6.5 x 6 x 1.5 inches (15.5 x 16.5 x 4 cm) when closed. It can run from an AC wall adapter or 6 NiMH AA batteries. The keyboard is hacked from a portable folding keyboard for a Jornada PDA which outputs RS-232. I’m using a PIC 16F88 to decode the signals and re-encode them to PS/2 (that was an ordeal to figure out). The PIC checks to see if an external PS/2 keyboard is connected on power up. If one is hooked up, it will route data from that instead. There is an internal ampilfied speaker as well as connections for audio and video output on the back. There’s a serial connection for a disk drive and an SD card slot in the side. I also have a connection for a userport/joystick. The joystick in the picture is a hacked Atari keychain joystick. The mini joystick wasn’t in the original plan but after I accidentally discovered it on ebay, it seemed perfect.