Minimig started in secrecy around January 2005 as a proof of concept by Dutch electrical engineer Dennis van Weeren. He intended Minimig as the answer to the ongoing discussions within the Amiga community on implementing the Amiga custom chipset using an FPGA. The project’s source code and schematics were released under version 3 of the GNU General Public Licence on 25 July 2007.
The original Minimig prototype is based on the Xilinx Spartan-3 Starter Kit, the Original Amiga Chipset is synthesized in the FPGA. Two printed circuit boards are attached via the FPGA kit expansion ports. The first one holds a 3.3V Motorola 68000 type CPU. The second has a MultiMediaCard slot with a small PIC microcontroller acting as a disc controller that supports the FAT16 filesystem and does on-the-fly Amiga disk file (ADF) decoding.
The prototype was shown at an Amiga meet and loaded most Amiga programs although bugs did exist. Van Weeren’s personal preferences led to the use of verilog instead of VHDL on a PC using Xilinx Webpack software for code development.
Purposes and intent
Run Amiga specific application software to convert files to newer platforms.
Freescale MC68SEC000, 3.3V, at 7.09379 MHz. However there’s no ‘E’ clock, MOVE sr,<EA> is privileged and there is no real replacement instruction. This does not seem to affect any programs as of yet.
Amiga Chip RAM bus and Slow RAM merged into a single synchronous bus running at 7.09379 MHz.
2 MiB 70 ns asynchronous SRAM organised as 2x 524,288 x 16 bit banks.
MCUPIC 18LF252-I/SP (An alternative would be Atmel AVR) implements a FAT16 disk layout and handles loading of FPGA configuration and Kickstart. Simulates a floppy to the Amiga by encoding on the fly from ADF files.