T he Orton 3C is a minimal Z80 computer which can run using only three chips. As Spencer says, the design is "on the border of simplicity and genius". Credit to Karen Orton, who is sadly no longer with us. It literally gets you hands-on with the Z80. Input of a program (or at least some kind of loader or serial program) is achieved 70s-style using switches connected to the address and data lines. Spencer has taken Karen's design and implemented it using the RC2014 modular form-factor. I love the bare-metal-ness of it but couldn't really justify buying one. One birthday later and here we are. Without using a ROM, programs have to be short or you have to settle down for a lot of toggling. You soon feel the limitations of having no input/output - even a game of 'kill the bit' requires the front-panel i/o (which adds to the chip count). My initial programs involved animating those output LEDs. Of course, any RC2014 module will work and so I tried a program t...