Zippy Zapp wrote: CD32Freak wrote:
It would be more impressive if he replaced the original chipset with FPGA's and creating an open sourced Clone-A
One that can use original floppy drives, and all the usual ports on an Amiga, sort of like the Ultimate 64. I could see that.
I don't mind the FPGA implementations that exist today but everything is emulated to the point where you can't really hook up anything to it besides keyboard, mouse and monitor. I want a replacement that allows complete compatibility with all hardware.
I agree, and this is how I'd do it.
Make three PCB's. One mainboard, two different IO boards and three different joystick boards. These would use right-angle headers like the Amiga 500 trapdoor expansion to connect with each other. The two IO boards are for the different layout between the 500 and 600/1200 and ordered separately. The IO and mainboard are the same "width" across the back.
The joystick PCBs can be mounted in either the A500/A1200 position (looking very long like the Ultimate 64) or sideways as in the A600 (making an "L" of the three boards). They come in three configurations: dual DB9, dual USB or single DB9+USB.
For the CPU, I'd use a simple DIP socket for a conventional 68000 processor allowing you to install a stock MC68000 or any of the many accelerator options available, up-to and including the Vampire V500. Since there's nothing about the Amiga chip set that leverages 32-bit addressing, the older 23-bit addressing and 16-bit data bus is fine -- even for most things AGA.
Finish off with a modest (12~24K Lattice EP5C?) FPGA for the chipset and 16Mb Pseudo-SRAM (and obligatory passive and level shifting). Should make for a fairly inexpensive setup.