In 1974 I went to a presentation near Fort Meade and a salesman gave me a sample of a chip which was to be a competitor to the 8080 and the Z80. All I gotI was the chip itself. They offered an evaluation board but it cost $147 and I could not afford it, Here is the ad for it:
I just made everything else and programmed it in machine language. Incredible Amount of work!
I acquired a floor cabinet frame with many edge connectors interconnected by wire-wrap. Eventually I made 15 boards. For display I made a monitor using a kit which had a Z80 in it and a TV tube. This took several years and ended up in San Diego in my present house. I still have some boards.