Have you checked out the NOVIX Forth Chip? That has a lot of great ideas you could apply, or at least find entertaining!<p>It had a horizontal bitslice architecture, and separate independent busses for main memory, operand stack and return stack, so several forth words that did some stack manipulation, used the alu, and returned from a call, could all be collapsed into one instruction that accessed main memory, the operand stack, and the return stack at the same time!<p><a href="http:&#x2F;&#x2F;www.forth.com&#x2F;archive&#x2F;jfar&#x2F;vol3&#x2F;no2&#x2F;article38.pdf" rel="nofollow">http:&#x2F;&#x2F;www.forth.com&#x2F;archive&#x2F;jfar&#x2F;vol3&#x2F;no2&#x2F;article38.pdf</a><p><a href="https:&#x2F;&#x2F;users.ece.cmu.edu&#x2F;~koopman&#x2F;stack_computers&#x2F;sec4_4.html" rel="nofollow">https:&#x2F;&#x2F;users.ece.cmu.edu&#x2F;~koopman&#x2F;stack_computers&#x2F;sec4_4.ht...</a>