http://www.diycalculator.com/sp-hrrgcomp.shtml Our cunning plan is to design ? and hopefully one day build ? what we are calling the Heath Robinson Rube Goldberg (HRRB) computer. This would be a (possibly cut-down) version of our DIY Calculator <http://www.diycalculator.com/aboutdiy.shtml>. However, we don't intend to simply replicate Harry's work ? where would be the fun in that? Instead, we wish to create something even more on the "Cool Beans" side (if that's possible). What we're pondering is a beast that combines multiple technologies (relays, vacuum tubes, transistors, silicon chips, etc.). Imagine a row of glass-fronted wooden cabinets on the wall. Each is implemented in a different technology, and each contains some portion of the computer, such as the system clock, the ROM, the RAM, the ALU, the CPU's status and control logic, the CPU's addressing logic, and so forth. We will elaborate on this core concept in the following topics ? what we're trying to do here is to convey our "vision." The idea is to first come up with a specification for the functionality to be represented by each of the cabinets along with a well-defined interface into ? and out of ? each function/cabinet. This would facilitate different design teams tackling the different cabinets. Furthermore, as opposed to having the cabinets linked by bunches of cables, we were thinking of providing each cabinet with a wireless communications system (or maybe they could communicate via the building's power cables, since each cabinet will require a power supply anyway). This would (a) make things look nice and (b) allow the various cabinets to be located at arbitrary distances from each other. Note that this project could grow to such a size that we'd need a big facility to host the final machine and display it to its fullest effect (possibly a museum or an airport or ... Contact Us <http://www.diycalculator.com/about.shtml> if you have any ideas ... all suggestions will be very gratefully received).