At 12:02 -0500 5/6/07, Pat wrote: Although I tend to agree with Pat about the "right mind" part of it, we routinely do this for spacecraft avionics. Both simple processors, like 8085, and more complex ones like SPARC architecture are implemented in FPGAs. The speed is generally far below what a "real" CPU would do, but because we can implement more functions than just the CPU into a single chip, and because we can often get an FPGA that has been tested to better radiation exposure levels than the corresponding (faster, smaller semiconductor feature) "real" CPU, it still turns out to be the best option in many cases. I really mourn the lack of availability of rad-hard CPU's anymore. Harris RTX2010 (a forth-oriented 8/16 bit) and the RAD6000 (a PowerPC-like unit) were both workhorses in the past. The FPGA's we use routinely come up with chip-level problems of one form or another (bad programming algorithms, power-up sequencing issues, etc.) that cause angst, board reworks, or other serious cost and schedule problems. That never used to happen with "real" CPUs. :-) admittedly, I can't really claim our avionics boxes are "widely available", though we're always looking for new customers.... -- - Mark, 210-379-4635 ----------------------------------------------------------------------- Large Asteroids headed toward planets inhabited by beings that don't have technology adequate to stop them: Think of it as Evolution in Fast-Forward.