Our children’s school (a Waldorf/Steiner school) believes that ideally children should build a computer before they use one. So I offered to work with the 15-16 year old pupils on this.
My first computer was a 1802 CPU based single board computer, which I had to solder together. It had a hexadecimal keyboard (0-9, A-F), a double-digit display (not a monitor, just two digits similar to the picture above), 256 bytes of memory (yes, bytes, not kilo bytes, not mega bytes). It had a very simple instruction set, which gave me an excellent insight into the workings of the CPU.
That is the experience I was aiming for: getting the pupils to get a real feel for how computers work.
I designed a simple Z80-based computer, and created a curriculum consisting of building computers in small groups, programming, and an introduction to the core elements of a CPU.
With a little help all groups managed to complete their computer and run some simple programs.