I don't think the requirement is there yet. 68B09Es are still available; they're getting a bit more expensive, but you can still pick them up for under $10 without too much trouble. They don't fail that often either, failures usually seem to be in the RAM, 6821s, sockets etc. When you say 'use a small FPGA development board', do you mean to emulate the entire controller board, or just the CPU? Just curious what you had in mind. On 2/07/2014 3:41 p.m., ben wrote: arcade market would use a small FPGA development board. relative here.