The best part about the MOnSter 6502 is you can control the frequency through a potentiometer :)
A really excellent way to switch between actually seeing the individual instructions being decoded and executed and getting something fast enough to be (barely) usable!
What's really attractive to me is that it's also an existing, "real" architecture instead of a custom one-off (which may have been designed specifically to ease a particular implementation.) It would be fun to see a discrete 8080, Z80, or even 8086, for much the same reason.
The first generation DEC PDP-8 minicomputer was a discrete-component machine the size of a small refrigerator.[1] Probably the smallest pre-IC computer manufactured.
My very first job after graduating college was working with a PDP-8. At one point we had a hardware failure. We had a maintenance contract, so DEC sent out an engineer. After confirming the fault from the diagnostics I had run, he pulled a circuit board out, unsoldered a transistor, and soldered in a new one.
We also upgraded the hardware while I worked there. We doubled the memory from 4K words (6K bytes) to 8K words. The upgrade cost five thousand dollars.
The smallest pre-IC computer is probably an aerospace computer. These computers are very interesting, but almost totally neglected. For instance, in 1960 Atlas ICBMs (nuclear missiles) were guided by a computer that was a two foot cube and weighed 240 pounds. Side note: PROM memories were invented for this computer, so missiles could be aimed at different targets in the field.
In 1962, Arma created the first microcomputer, or at least the first computer with that name. The Arma Micro Computer was a general-purpose aerospace computer built from transistors and transfluxors (two-hole core memory with a cool name). The computer was a tiny 0.4 cubic feet and 20 pounds. It was a 22-bit machine; while we now think word sizes must be a power of 2, back then people used whatever word size gave them the accuracy they needed.
The original Atlas guidance computer was ground-based.[1] It was the first transistorized computer, but it was a sizable mainframe and not on the missile. Guidance was by radio control.
The ARMA Micro D is really obscure. It shows up in some lists of early computers. Apparently it was inside some versions of the LTN-51 inertial navigation system.[2][3] But this seems to have been around 1969-1970. The Concorde used that navigation system.
8080 would probably be doable, but the Z80 has over double the transistor count, so it would be (even more) impractical to construct. The 8086 has an order of magnitude more transistors.
A really excellent way to switch between actually seeing the individual instructions being decoded and executed and getting something fast enough to be (barely) usable!