<Anybody got info on a Nat. Semi. 57109 "Number Oriented Processor"? <I've got one on a "calculator interface" board, that I suspect was <a primitive math coprocessor. I'd love to get specs on it, and/or It was a calculator chip I believed based on the 4bit cop series. It's been a long time. Anyhow the board used a calculator chip despite it's slowness to avoid higher math (to 8 digits) in software. It was however not a coprocessor, it is a limited slave at best. <replacement chips in case this one dies. You might get lucky... Allison