Replicated motherboards, any interest?

[billt]

An interesting idea, make an FPGA board shaped like each Amiga motherboard as I take it.

How about this: Use or design some standard module to hold the FPGA(s) themselves, which connect to each such new Amiga replacement motherboard through the same connections of whatever kind it may be. Then each motherboard routes the FPGA pins as needed for that motherboard. Perhaps not all pins are used in each motherboard, such as pins for Zorro2 on A2000 are nothing on A500, but there are enough pins for A3000 or A4000 as well. Perhaps a couple FPGA modules are needed together to fill out enough pins to do everything if A3000/4000 CPU slot is present as well as Zorro and all other connectors. The motherboards get simpler this way, they basically hold connectors, routing between them, level shifting as necessary to the FPGA modules, and whatever PHY type stuff at the connectors. If you need more than one FPGA module, they are all the same thing, not different modules in different places. Each motherboard may have a different configuration to the FPGAs, but the modules don't need to get specialized for anything, for reducing engineering iterations/redundancy. If multiple ones are needed in a machine, some pins will connect them together in a suitable way as needed per motherboard.

And while you're at it, swap ISA slots for 3.3V (or universal if slots can be that way) PCI slots on A2000/3000/4000 and give them an active bridge to be useful.

Would you intend to have CPU slots present, or expect to use softcore 68K? CPU slot makes PowerUP board usage and OS4 Classic possible for machines that take them...

Or, since we're reinventing things, why not turn A500s into A1200s, A2000s into A4000s, etc? Does that go beyond what you want to do, by leaving out people with broken A2000s now not being able to use their A2000 addons, and this is not what you want to do?

And then go crazy, put MXM laptop graphics slots in the keyboard style computers, muxing their outputs with the "Amiga" graphics outputs like some Zorro gfx cards can do (PicassoIV for example), maybe laptop mini-PCI for wifi slot, internal SATA perhaps if chosen FGAs can do that, etc.

[billt]

Better keep to the specifications. ISA is 5 V in all cases, even thoe 3,3 V logic is accepted at input. Any FPGA must tolerate 5 V from ISA cards. And PCI is nice but it is timing tricky and I/O heavy.

5V is not that big of a deal.
http://users.ece.gatech.edu/~hamblen/UP3/IDTQS3384AN.pdf
http://www.xilinx.com/support/documentation/application_notes/xapp646.pdf
http://www.altera.com/literature/an/an330.pdf

If the person designing the board can't get PCI timing right, then I wouldn't be very optimistic about the other things either... This would require someone that knows how to do this stuff properly with or without PCI.

And in the big-boxes, consider at least one slot having a PCI to PCI-Express bridge to a x16 plastic slot to hold a modern graphics card, even if it's only a x1 slot electronically running at PCI bus speed. (yes, that bridge chip adds cost)

Though I guess some people might want to continue using brigeboards or Goldengate ISA bridges and their collection of ISA cards. Did they do PCI to allow the user's option of a rear bracket holding EITHER an IDA card or a PCI card? Maybe do both, FPGA pins permitting of course.
http://www.kids-online.net/learn/click/details/sharedpi.html

By loading the correct image you can downgrade at will.

I was thinking more along the lines of putting an A3000/4000 style CPU slot on the A2000 replacement motherboard instead of an A2000 style CPU slot. (or if you're crazy enough and have enough FPGA pins, both) Then it could have a CSPPC card and run OS4 as well as get AGA etc.

This will likely increase cost in a non-benefitial way. Better to use plain junk PC for such uses.

A slot and some wires, should FPGA pins allow? OK, depending on version of MMX slot it'd require a PCI-Express IO capable FPGA. And someone to make a PCI-Express logic to drive it. Or perhaps a PCI to PCI-Express bridge chip from PLX etc. But leave the slot empty and leave it to user to choose to put something there... If I was the designer, I'd consider the possibility of modern graphics card in A500, A600, A1200, A1000 even, as a desirable possibility.

What we really need is a proper production run of Amiga keyboards that plug into USB or ps2.

It'd be easier/cheaper to make the reverse of the adapters allowing standard PC keyboards to work in Classic Amiga motherboards. Then use an existing Classic Amiga keyboard.

Speaking of keyboards/mice, I'd try to design things so that these replacement motherboards can take at least PS/2 with a direct pin adaptor, not to need the special Amiga protocol adapters. Not sure if there is a direct mouse pin adapter that would fit an Amiga mouse port to design toward, may need the special Amiga adaptor to PS/2 mouse, or perhaps a not done before direct pin adaptor can be done and move protocol part into FPGA, cheaper than special protocol adapters we have now? Someone else already provides PS/2 port to USB keyboard/mouse adaptors.

Also, if not an Amiga style accelerator slot, then consider making the motherboard a Com-Express carrier and mux outputs of that with FPGA outputs.  (And FPGAs still on their own standard modules to the new motherboards) There's modern PowerPC modules for that standard. While they are not supported in  OS4 now, maybe we can get there, and have as modern stuff in our Classic cases as we can get. And motherboard is still a relatively simple PCB doing little more than connections and close-to-port electronics (serial port level shifters, video D/As, analog D/As, etc.)

I just think that if you're going to the trouble to make a replacement for a Classic motherboard, then give it some modern update options where it makes sense to do so. I think that going to this effort and leaving out PCI would be an odd choice.