While the ‘Raspberry Pi – 2006 Edition’ lacks some of the power of its more modern counterpart – thanks largely to the use of an Atmel ATmega644 microcontroller running at 22.1MHz and a mere 512KB of SRAM, compared to the 700MHz ARM process used in the modern edition – it’s a lot easier to build at home.
“These boards use an Atmel ATMega644 microcontroller clocked at 22.1MHz, and a 512K SRAM for data and framebuffer storage,” Upton explains. “19 of the Atmel’s 32 GPIO lines are used to drive the SRAM address bus. To generate a 320×240 component video signal, the Atmel rapidly increments the address, and the data lines are fed via 74HC-series buffers to a trio of simple summing-point DACs; during horizontal and vertical blanking, it is free to perform other operations.”
The upshot: a microcomputer you can build from off-the-shelf components on Veroboard, capable of producing simple 3D graphics at a 320×240 resolution.
The below video, released by Upton, shows off the device’s capabilities, while the schematics and a PCB layout can be downloaded directly from Raspberry Pi.