Breadboard RPN calculator

[EugeneNine]

When I was still in school I designed on paper a 4 bit CPU. Since most CPU's work by putting numbers in two registers and then executing a instruction to do something with them and they have a stack its pretty much like RPN. In college I started building it all in LogigWorks but never finished as my Amiga 500 started getting pretty slow as I kept adding more and more logic gates,
I should build it someday.