A6000 wrote:
Well I will admit that this task is beyond me, but well within the capabilities of others on this forum. but I would start with the circuit and pcb design of the 4000D and:-
1. replace fast slot with cpu socket, this can accept 040 or 060 since there will be more 040's available than 060's. the programmable clock speed allows any speed version to be used.
2. replace AGA chipset with minimig FPGA.
3. implement memory, SDR is old and expensive, DDR2 may be more economical.
4. implement hard drive interface.
Job done?
P.S The PPC can go on a board plugged into the cpu socket.
Someone else has already stated it but you're talking about something like the Clone-A. Where you start by replacing each of the chips in an A4000D motherboard with fpgas and "just" duplicate the motherboard design.
That won't really work for several reasons. The main one being duplicating the motherboard design as it isn't really easy or possible for hobbyists and it's not economical for a professional company.
Don't let that be the end of the idea though.
What I meant in my reply was to start from the MiniMig v1.1 as your base. Decide what you want and then figure out what you'd need to do to change the v1.1 into the thing which supported that idea. Then you move onto the next part of it and do the same. Repeat until you've got all of your features and voila! You'll have got a MiniMig4000.
Also as someone already said, SD-RAM is still cheap and plentiful due to its use in just about everything from washing machines to set-top-boxes. Also for the speed of the 060 and PPC chips its plenty fast enough. DDR can come later but start off easy!
For the A4000D you'd want what? an '060? Ok figure out how to add that, just with pen and paper compare what the MiniMig has now and what you want it to have. Go and lookup the datasheet on the Freescale website and see if as alexh says it uses 3.3v or 5v for it's IO lines. If it does use 5v then you know that you'll need voltage shifting hardware.
Make all of the things that you discover into a list of things that you _reasonably_ think you'd need to do, but don't know how, to put a 68060 processor onto a MiniMig v1.1 physically. Don't even worry about the code used in the FPGA for now just think about that one small area.
Once you done that, come back and ask again about how to actually do those things or see if someone would be willing to design them for you. Basically get someone to sanity check them.
Andy
