I have:
  • One bit of working memory
  • One bit slice of the ALU including fast carry
  • An architecture that seems to provide both basic hardware and software support
Which may not seem like a lot, but it's definitely coming together.

Current tasks are: 
  1. Decide whether it's a 2 or 3 phase state machine.  2 phase needs bus-B to be able to write and so more diodes, but may well be simpler to understand and a bit faster.
  2. Get my FPGA running and build everything in Verilog
  3. Look at tcc - can I port it to my instruction set where everything is 16 bits?
  4. PCBs?  Can I get away without the expense?  For example, can I print onto A4 paper and glue that to one side of perfboard?   How do I connect matrix board bitslices?
  5. Build a complete bitslice, that's 6 bits of memory, two constants (0 and 1) and one bitslice of the ALU all addressed by two read variables and one write variable.   The inputs are three registers at three bits each plus 3 bits to specify the ALU instruction, the output is witten to the write register. 
  6. Plan out the detail of the instruction set decode
  7. Rewrite the emulator
  8. Write eForth for the emulator and go back and tweak instruction set if needs be
  9. Build for real...