As I've been trying to get my 65816 running, I've built a breadboard version and a solderable prototype board version. Managing the wiring while constantly changing things has been a bit tricky (and frustrating at times). To help with the wiring mess, I've developed a PCB for prototyping.
I ended up with a two-layer board that's approximately 300mm by 200mm (12in by 8in). I would have gone with a four-layer board with inner planes for VCC and GND, but the EDA tool I'm using, EasyEDA, is completely broken when using inner planes on four-layer boards.
And, of course... five minutes after ordering the boards I came up with more design changes. :) Oh well...
There's nothing exciting to the schematic. I tried to give myself flexibility in how I use the board, connecting VCC, GND, address and data lines to the core components. I added eight 14-pin sockets for general logic ICs. I included a couple of options for address decoding (ROM or PLD). I have plenty of headers added for quick connections, including address signals, data signals, control signals, VCC, GND, all the general logic ICs, etc. I also included LED bar graphs on the right of the PCB for many of the signals. I even included a pair of VIAs, so if I can get the core running, I can add a display, keyboard, or sound card.
Postscript
First fire up...
I really like this design, I built my 6502 board with every control line I could think of output to a header that could plug into a breadboard. It helped with some things but didn't give me nearly enough flexibility for building out.
I'm taking inspiration from this as I move to my next board which will also include a bunch of GALs available for logic as well.