Make a mechanical computer

Through my computer history and horology contacts, along with some targeted searching on the net, I have collected a good deal of the designs for Babbage’s Analytical engine. The next step would be to visit the archives where the papers are stored. Doran Swade estimated that it would take his team some millions of dollars to do much of what I have done.

Of course our methods are different. Doran, is working to make it just like it would have existed in the 1850s or 1860s. Doran has good arguments as to why a mechanical computer, designed in the 1830s is not likely to have been made before about 1853. His goal is to answer the question, could it have been done then? His approach is to match the metallurgy, surface finish and make a 19th century machine in the 21st century.

My approach is more pragmatic. As far as Alan Bromly or Tim Robinson were able to learn, Babbage did not have the concept of an instruction set. This makes any modern re-construction suspect. The other issue is that the Analytical Engine was huge, about the size of a steamboat or locomotive.

Bromly left some fascinating articles written in the early computing and horology journals. These observations combined with a simple paper training computer called Cardiac, produced by Bell labs is a great entry point into making a 3 digit decimal computer using Babbage’s concepts.

By scanning in much of the publicly available information, I have made some 3D models of the adding mechinisims, These look perfect for making on a repap 3d printer. This is where I was a year ago when I discovered the world of three dee printing.

So over the course of the next few blogs, I will take a look at the reprap process, and just how practical will it be to repstrap a Mendel.