Dave, I'm open to anything. I'm not trying to reproduce historically accurate hardware, and I'm probably going to use surface mount devices to help get the size down. Up until recently, I was going to use diode matrices, but they're a bit difficult to re-program, unless I put a 2 pin header and jumper on every diode. I had forgotten about core rope -- that might be an idea worth pursuing. - Keelan On Tue, Mar 27, 2012 at 3:59 PM, Dave Tweed wrote: > Are you trying to find discrete equivalents of what goes into a modern ch= ip, > or is it OK to use technology appropriate to the era when transistors wer= e > actually used to build computers? > > In the latter case, a "proper" transistorized computer would have used fe= rrite > core memory for rewritable nonvolatile storage, and either a diode matrix= or > "rope memory" (like the Apollo spacecraft computers) for one-time program= mable > memory. > > -- Dave Tweed --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .