DREAMING: Breadboard, DDR socket and an mBed

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I have an mbed here, and it is pretty fast responding to interrupts... So I expect that with an external clock (the internal timers seem to be micro second accurate so not precise enough for bus sampling) it might be able to keep up... Your big problem is lack of I/O, as realistically, you've got under 30 pins and the address/Data bus of the 68000 needs 52 alone!!

An FPGA might be better here

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Regarding the number of I/Os on the microcontroller (of any type), do they have to match 1:1 to each pinout on the CPU or do they only need to communicate with the pinouts on the trapdoor bus edge connector (and are those the same number of pins as the CPU?).

Also, why do they need to match? I was of the (likely misguided) impression that by the time the data reached the bus edge connector we'd be going through some software layer already and wouldn't need quite soo many GPIOs. Look at me, using acronyms like GPIO.

Can you recommend a getting started guide for things like resistors, capacitors, diodes, etc...? My only understanding of them comes from the world of car audio installation and does not directly relate to all the things needed in the world of microcontroller hackery.

Final question in this reply, do you think SDCard speeds are fast enough for a stock A1200 SLOW RAM? I mean the CPU is running at what? 14MHz? Maybe I have a totally misguided understanding of BUS speeds on the stock A1200.

This is what you need:

http://www.falstad.com/circuit/

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The lack of viable 5v parts is a serious problem in new Amiga designs.

You spend half your time just trying to interface available parts without screwing up the timing and adding latency.

3.3v tolerance is becoming harder to find even.

Plenty of Microcontrollers are still 5v tolerant... But I think you are right about FPGA, where even 3.3Volt is old now...

It's getting harder to find video display equipment that will acce

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The lack of viable 5v parts is a serious problem in new Amiga designs.

You spend half your time just trying to interface available parts without screwing up the timing and adding latency.

3.3v tolerance is becoming harder to find even.

Plenty of Microcontrollers are still 5v tolerant... But I think you are right about FPGA, where even 3.3Volt is old now...

It's getting harder to find video display equipment that will accept an Amiga Video signal too... The Amiga is old :-/