Garth Wilson here. Self-proclaimed Forth guru, um...no; enthusiast and user, definitely. The 6502 Forth I'm using is one that was modified from fig-Forth to Forth-83, and then I further modified it and added a lot to it, including zero-overhead interrupt service in high-level Forth, as described in one of the first articles I ever wrote, at http://wilsonminesco.com/0-overhead_Forth_interrupts/ .
My 65816 Forth however is something I did pretty much from scratch in the mid-1990's and has sat collecting dust most of the time since then, but I have recently pulled it out and implemented a the major upgrade of easy installation and management of low-overhead prioritized interrupts in both assembly language and high-level Forth. This was quite a challenge to debug, because until the new interrupt system was working, there wasn't the interactiveness that makes Forth so quick to develop in.
There's so much optimizing that can be done on the '816 compared to the '02, since its ability to handle 16 bits at a gulp takes the memory penalty out of turning secondaries into primitives. It's actually easier to write for the '816, and my '816 Forth runs two to three times as fast as my '02 Forth at a given clock rate. I hope to eventually it ready for publication.
My 65816 Forth however is something I did pretty much from scratch in the mid-1990's and has sat collecting dust most of the time since then, but I have recently pulled it out and implemented a the major upgrade of easy installation and management of low-overhead prioritized interrupts in both assembly language and high-level Forth. This was quite a challenge to debug, because until the new interrupt system was working, there wasn't the interactiveness that makes Forth so quick to develop in.
There's so much optimizing that can be done on the '816 compared to the '02, since its ability to handle 16 bits at a gulp takes the memory penalty out of turning secondaries into primitives. It's actually easier to write for the '816, and my '816 Forth runs two to three times as fast as my '02 Forth at a given clock rate. I hope to eventually it ready for publication.