On Mon, Jun 15, 2015 at 04:55:57PM +0000, tony duell wrote: > > Unfortunately I believe you. Use at least a thousand times more components > than > you need to.
Actually it's just two, a Teensy and a usb cable. (Sorry, I couldn't resist). > > In general this worries me if you are restoring a vintage > minicomputer. How on earth can you hope to fix a TTL-built CPU without > knowing the common TTL chips and without having a few on-hand? How do you suggest I learn? I believe you had a father that got you of to a good start and perhaps you even took a few classes. My father was great but knew very little about electronics. And TTL on the minicomputer level was way out of fashion when I went to school. Certainly no excuse, but one of the main reasons I'm in this hobby is to learn! And boy have I learned a lot since I got started. I'm not at your level yet.. but perhaps in a few years I'll be a tenth of the way there :) It might please you to hear that the Teensy I'm talking about is in a socket on a perfboard together with a handfull of 74165 and 74374 which I've wirewrapped in proper wirewrapping sockets. It will become a USB interface for my 11/70 front panel. The Teensy was the simplest/cheapest way to get a usb interface with lots of I/O pins. (Why usb? to get a connection to simh on one of those newfangled Pi-things) Cheers, Pontus.