Browse around eBay for an original Altair 8800 and you quickly find that the price range is in the thousands of dollars. If you are a collector and have some money in your pocket maybe that’s okay.

There was a time when building electronics and building software were two distinct activities. These days, almost any significant electronic project will use a CPU somewhere, or — at least — could.

The first name on the list is Autodesk Eagle, an engineer-friendly tool that boasts a vast library of resources. It offers a full suite of PCB layouts, schematic editing tools, and collaborative ...