Old printed circuit boards
Old printed circuit boards
HI:
I see what you want to do. What you really need is some of what we used to call "logic modules". They were boards made with logic functions on them, the input and output from them brought ot to the pins on an edge connector that the boards were plugged into, Practically all computers, whether general purpose or special purpose, were made that way. (The concept of a single bus bakplane first appeared in the PDP-11 in aout 1970. ) I do not know about every computer but all those I ever worked on (about 25 different models from about 10 different manufacturers) were built that way, and I know that some military stuff was too, like the Appolo on-board computers and some so-called "Mil-Spec" computers that were logically the same as a non-Mil Spec. model from the same company. An example was the Univac 1218 and it's civilian companion the Univac 418. The IBM 1130 and the IBM 1800 were basically the same machine, one made to commercial specs and the other made to meet the more demanding requirements for the process control market. What I would do if I were you would be to write to all of the National Labratories and major research universities and explain what you wish to do and ask them if they have any surplus equipment around that was made using the Logc Modules from Digital Equipment Corp, Scientific Data Systems, Compter Control Corp. that you could get for your work. (Note that SDS became XDS and CCC beca,e Honeywell in the late 1960s)
There is one potential problem to consider. Each company (and I have named only three that we used often) used different voltages for the logical levels. Some used a positive voltage and Gnd to represent a 1 and 0, while another might use Gnd. and a negative voltage to represent a 0 and 1, and others might use the same voltages but with the convention on 1 and 0 inverted. So, you would have to find the appropriate modules to invert and/or convert these logiv levels.
I would suggest that you look through this Forum for someone offering some DEC "Logic Module Handbooks" which would show you what I am discussing far better than I. One thing more that I can think of off the top of my head is that every company that made them used a different Edge Connector.
I like your idea, and would love to do something like it if I had a place to work and wasn't 74 years old and plagued by every sleep disorder known to man. So good luck and I hope you can make sense of this and that it is of some help. If I can help you with a list of places to contact, or anything else, just give me an email via the forum.
Ray