I realise I am getting ahead of myself here, because I don't have any functioning hardware yet (the board is designed, but I haven't sent it off for fabrication).
We'd be happy to know the details of the hardware if you care to share them. (Y' might want to start a new thread for this.)
Anecdotally: my own solution to the chicken or the egg problem was to manually enter FIG in the form of about 8 kbytes of hex.
(This was pre-DOS days for me, and I had no assembler of any kind, just a KIM-1 with Cheap Video and some added memory.)
However, I don't think there would be too much work to get FigForth to compile itself. I think what is going to make things complicated is getting it to relocate itself - once it has been compiled.
Later in the 20th century I embarked on a project that's broadly equivalent to what you seem to have in mind. And indeed it did lead to "some interesting experimentation"
as you say; but, contrary to your expectation, it was a LOT of work. Perhaps I inadvertently adopted a sub-optimal approach, but OTOH perhaps my gnarly solution was unavoidable, given the tools I had to work with and the inherent Catch-22s to be resolved.
What I developed was dozens and dozens of screens of source code (which my KK Computer was capable of reading in from floppy disk). When I asked FIG Forth to LOAD this sequence of screens, Forth's DP -- the dictionary pointer -- would get moved up to $8000 or thereabouts. Then, still chaining back to the original dictionary in low memory, a whole new Forth installation was assembled and compiled. (Ragsdale's assembler was part of the parent FIG installation.)
Did I mention Catch-22s? It was HORRIBLE! I wrote a variety of novel, ugly hacks (some of them reminiscent of Screens #70 and #71) because FIG Forth doesn't seem to include the hooks that would make self-re-creation straightforward and sanitary.
Nevertheless, I eventually was successful in getting the new Forth running up at $8000, and the last step was to sever the connection to the old dictionary. Believe me, that felt like a heckuva victory! Whew!!
At last I was running a system created under my control from source code I provided, and -- with this major advantage achieved -- I then became distracted with other shiny toys, and didn't carry the thing as far as originally planned. My
intention had been to revise the code until what got placed at $8000 was a Forth that had the hooks in place to make things easy and allow the Catch22s to be worked around. After that, all subsequent iterations could be done cleanly! For example, I envisioned being able to put DP back down at $0200 and -- without resorting to ugly hacks -- use my new installation to create yet another new version of itself. But this never happened.
Sadly, I'm not easily able to share the dozens and dozens of screens of source code I mentioned, because nowadays KK and its floppy disk SBC are finding it almost impossible to get out of bed in the morning. But I tend to think you don't wanna see that code anyway. There's gotta be a better way to achieve a self-re-creating Forth! And very likely it has nothing to do with FIG. Screens #70 and #71 seem to suggest that I'm maybe not the only one who was
trying, but....
-- Jeff
