Design & Prototype
The first task was to write a C++ class which emulated the Kenbak's "CPU" and instruction set. It only has 256 bytes of memory with certain locations corresponding to "registers". The instruction set is clearly documented in PDF scans of the original typewritten documentation. With that aspect of the software sorted, and confident the rest wouldn't be a problem, I moved onto the tricky part: the hardware. The driving factor here was mostly scale; the sizes of the LEDs and pushbuttons I intended to use. They determined the over-all scale of the project and its proportions. I found a suitable project box without much trouble and began work on squeezing everything into it. Note that I decided almost immediately to discard the Kenbak's Power and Lock switches.
I spent quite a lot of time planning the circuit and even prototyped the buttons-and-LEDs sub-assembly.
Design & Prototype
The first task was to write a C++ class which emulated the Kenbak's "CPU" and instruction set. It only has 256 bytes of memory with certain locations corresponding to "registers". The instruction set is clearly documented in PDF scans of the original typewritten documentation. With that aspect of the software sorted, and confident the rest wouldn't be a problem, I moved onto the tricky part: the hardware. The driving factor here was mostly scale; the sizes of the LEDs and pushbuttons I intended to use. They determined the over-all scale of the project and its proportions. I found a suitable project box without much trouble and began work on squeezing everything into it. Note that I decided almost immediately to discard the Kenbak's Power and Lock switches.
I spent quite a lot of time planning the circuit and even prototyped the buttons-and-LEDs sub-assembly.