The current design of the microcode structure is almost complete, with just a few loose ends that have to be solved.
However, the total design effort for the project will be quite huge, and it would be a pity if the result is inferior on certain aspects. It seems that with a little more effort, a better result can be obtained (at the cost of a few more components).
This will focus on two main aspects:
- Most instructions are just moving data around. If we change the bus from 8 to 16 bit, the system will run almost twice as fast. The ALU might
stay 8 bit to keep the part count reasonable (This will perhaps only cost a single extra cycle for instructions that do calculations).
- Several aspects of the Kobold are inspired on the PDP11. With some more effort, the design could be such that the microcode can implement a binary
compatible PDP-11 instruction set. (This will only be practical with a 16 bit bus).
So, work to do !