This is the default behavior for most all vintage 8-bit Forth implementations. To do a bounds check might take 6-10 machine cycles for every word. This does not seem like a lot, but it would have a noticeable impact on performance.
When I ventured Forth a few years ago I found that Forth Inc has a PC based Forth Dev system that is pretty forgiving and a good way to learn without crashing a machine. https://www.forth.com/ . There is also a good online Forth tutorial with a web based Forth implementation: https://skilldrick.github.io/easyforth/ I got the most out of DurexForth which is a modern Forth implementation on the C64. You still get the vintage goodness but with a good VI like editor and actual file support rather than the super goofy and crude typical Forth screens and blocks. I did a few cheesy Forth videos at the time too: https://www.youtube.com/watch?v=TXIDqptXmiM (lots of links in the description). Jeff Birt From: M100 <[email protected]> On Behalf Of Alex ... Sent: Sunday, March 28, 2021 9:39 PM To: Model 100 Discussion <[email protected]> Subject: [M100] Does anyone actually use MFORTH? Hello Tandy laptop nerds, So I've been reading Leo Brodie's "Starting Forth" and using my '102 as a playground / labrat. There's been a few inconsistencies I expected and can live with/work around, but I've noticed what seems like really bad bugs. It seems trivially easy to underflow the stack into la-la land. (For example: . . .S after a fresh boot will get it stuck spewing memory all over the screen) Has anyone actually used MFORTH for more than just simple tests? Is there maybe some hardware quirks involved here that don't exist on the Virtual-T emulator? Figured I'd cast this one out and see if anyone bites. -Alex -- Disclaimer: Any resemblance between the above views and those of my employer, my terminal, or the view out my window are purely coincidental. Any resemblance between the above and my own views is non-deterministic. The question of the existence of views in the absence of anyone to hold them is left as an exercise for the reader. The question of the existence of the reader is left as an exercise for the second god coefficient. (A discussion of non-orthogonal, non-integral polytheism is beyond the scope of this article.) Thanks /usr/games/fortune
