The C-One is a single-board microcomputer designed by Jeri Ellsworth, a self-taught designer, and Jens Schönfeld, who manufactured the boards themselves. It was initially created in 2002 as an enhanced Commodore 64 home computer, but has been reengineered to allow cloning of other 8-bit computers. The machine uses a combination of configurable Field-Programmable Gate Array (FPGA) chips and modular CPU expansion cards to create compatibility modes that duplicate the function of many older home computers. The default CPU is the 65C816 CPU which is used in Commodore 64 compatibility mode as well as the C-One's native operating mode. The C-One is not merely a software emulator, it loads various "core" files from disk to configure the FPGA hardware to recreate the operation of the core logic chipsets found in vintage computers. This provides for a very accurate and customizable hardware emulation platform. The C-One is by no means limited to recreating historical computers - its programmable core logic can be used to create entirely new custom computer designs. In 2004 the platform was expanded to include an Amstrad CPC core made by Tobias Gubener. So far, C-One circuit boards have been produced by German company Individual Computers, and they currently sell for €269. In 2006 a new Commodore-64 core was created by Peter Wendrich. [1] It is a port of his FPGA-64 project originally targeted for a Xilinx FPGA development kit. This core supports both PAL and NTSC machine emulation. The aim is to make it cycle-exact and emulate many of the bugs and quirks of the original hardware. In August 2006 the Japanese company D4 Enterprise launched the 1chipMSX, a system that is quite similar to the C-One conceptually, but is cheaper as it is much smaller and housed in a transparent plastic enclosure. It sports the powerful Altera Cyclone EP1C12Q240C8. This system can also emulate many other systems, including the Commodore 64.
