Perhaps a little FPGA or second microprocessor could sit between the Coldfire and the datastream from the Mac and monitor the instructions as they go by and provide translation as needed. Yet, you need some mechanism for intercepting non-compatible 68K instructions and translating them, otherwise. Ideally, you'd want the Coldfire to execute instructions without any other processing, when an instruction is compatible so that you don't lose any CPU cycles. If the processors are down under $30 each I'd say that it is very doable project, although I'm unclear on how you get the board to run 68K code without losing too much performance. I haven't looked at Coldfire in a while but are they 32 bit wide processors? How much does the 300 MHz version cost per chip? Which version of the chip is most 68K compatible? So even if you designed and built such an upgrade, it would cost in the neighborhood of $200 each even if you gave your time away for free and assumed the risk of not getting your money back after building some number of units.īut if fast Coldfire chips are, say, $30 each, then that would be an affordable upgrade.
The problem, in my mind, with the 68060 accelerator idea is that the 68060 chip costs (last time I checked) well over $100 per unit. The first thing to do is to price ColdFire chips of the type you might wish to use.
