The aim of this project is to produce a working free computer design along with a set of useful models and tools. The idea is that all the workings of the design are visible and open to understanding. The usefulness of the resulting computer is of secondary importance.
Each chip in the computer must be simple enough that a detailed model (rather than just a behavioural model) can be produced on the back of an envelope. This criterion is still a little subjective, but I think it gives the right idea. I want to rule out microprocessors and micro-controllers, but I want to include simple logic and RAM chips. The reason for this restriction is to ensure that the design is not obscured by the use of complex chips.
We want to produce the following items:
The computer should support the following devices/interfaces (with host and slave support for interfaces where this makes sense):
This may take a while. :-)
With so many peripherals, it makes sense to separate the work out into separate tasks which can be completed independently. To achieve this, I plan to have a backplane with plug-in cards. There will be a standard (although not too standard) interface between the backplane and the cards.