I’ve been following Xmos and their great multi core microprocessors for over a year now and a recently listed project recently listed on XMOS community site caught my attention. The XShell (and XGS) project is a minimalist computer with 32M bytes of SDRAM and complete with VGA, keyboard and SD card interfaces. On the software side it offers a simple shell, editor and interpreter making a basic computer system.
Nothing spectacular there you might say, it sounds like a basic DOS PC from the very early 90’s but what is awesome apart from the RAM the entire computer is executed in software on a single microprocessor chip with no dedicate interfaces!
That’s right, only software is used to generate the VGA screen as well as all the other interfaces: keyboard, 1-bit audio, SD card interface and joystick.
* Processor: Xmos XS1-L1-128, Single Core, 400 MIPS
* Memory: SDRAM – 256Mbit, 32M x 8; Serial FLASH – 4Mbit, 512K x 8
* Display: VGA 640×480 with 256 colours; Text Only
* Storage: SD Card using FAT16
* Interfaces: PS2 for keyboard/mouse, Joystick, 1-bit speaker/audio
* Software: Shell, Text Editor, Simple Language Interpreter
One the first things that struck me about this was it would be a great canidate for the $10 computer for developing countries.