This is the micro:bit. It is a pocket sized computer system with motion detection, a built-in compass and Bluetooth technology that can be used to learn programming and electronics.
What you see here is a Commodore 64 cartridge that I have created by sticking an EPROM and some other components on a breadboard.
A while back I also made a prototype for C64 PLA chip replacement, but I never did any further tests and completed the project. I thought that it was time to do some more tests on the chip. But will it pass the tests? Let's find out...
The basic building blocks of FPGA chips are logic elements (LEs). A logic element consists of LUTs (look-up tables), which are basically programmable logic gates. This gate is a multiplexer and can be build out of NAND gates. This small project is a breadboard implementation of this concept.