6502.org

To be fair, I'd rather suffer bitrot on an eeprom than in my brain. That scares me, and projects like this keep my brain exercised. I wouldn't want it to be thought that I was considering giving up, just noting that there could be simpler ways to do it.

I started a formal German course this week; thirty hours a week for the next six months or so...

Neil

good move - learning a language is said to be a good precaution against rot

Testing algorithms in C prior to reducing them to assembly language is a sensible route.  I used Thoroughbred BASIC to model my binary sequential time algorithms, which are very math-heavy, with 64-bit multiplication and division being used a lot.  Taking that approach likely saved me many hours of debugging, since when I finally wrote the assembly language equivalents, I knew my algorithms were correct—debugging was a matter of getting the LDAs and STAs correct.
Although science hasn’t conclusively shown a direct link between lack of cerebral activity and dementia, I think there is enough anecdotal evidence to support the idea that the brain, in a sense, is like any other muscle: it will atrophy absent regular exercise.  Like you, I do things that require often-hard thought as a hedge against developing dementia.  Playing music, I think, is good for preventing cerebral bit rot, as is writing 65C02 machine code to beat on FAT32. 
Wie Ed sagt, ist das Erlernen einer Sprache eine hervorragende Möglichkeit, die alten Synapsen zu trainieren. 

Just remember: Deutsche Sprache schwere Sprache
But it's always good to learn new things. I started learning Dutch last May — 20 to 30 minutes every day.

P.S.: If you need some help, feel free to send a PM.

Yeah. My favourite one (which I think I posted here quite a while back) was when I asked ChatGPT for a simple "add two 16-bit numbers on a 6502" routine and it added the MSBs first, and then added the carry from that to the addition of the two LSBs.

While things are definitely improving, the LLMs are still nowhere near (and showing no indication of getting anywhere near) being anything more than an assistant to someone who already knows how to program and develop software. I pay for Claude and use it a fair amount, so as soon as I'd heard that the new Opus 4.6, with all the extended thinking etc. turned on, was finally going to do things right, I turned it on. I am still daily getting utterly stupid errors, as well as more subtle ones that I'm reasonably sure that someone without my level of experience won't be able to identify.

I guess, since it's been a couple of years, I should have Claude do another pass over some of my more highly optimised assembly code to see if it's any better, but I'm suspecting not. For basic syntax etc. you can expect it to do pretty well with extremely popular languages like JavaScript and Python, but I doubt it would do well with Algol, much less something so different as 6502 or similar assembly languages.
Assembly language is hardly unknown on the Internet. Now you might find a few 80386 instructions in your LLM-generated 65C816 code....
Yes. LLMs tend to copy and paste code. A lot. Which is why I (amongst many others) currently have a job fixing the results of that. :-/
Which is rather misleading, because of course what some CPUs have and others don't is precisely memory and time.

I mean, sure, you can use memory to substitute for registers in your 6502, and then after you've already increased your memory usage you can use yet more to deal with all the overhead of bank switching so you can get more memory, and so on, but even if you're willing to do al the work (including all the debugging), you've gone from a hundred times slower to tens of thousands of times slower than a VAX, and you're in that world where, theoretically, you can break any passphrase or encryption key because it's just a matter of time, right? (I think here is where that "sometimes quantity is a quality of its own" thing comes in.)

So, no, doing a thing that works fine on CPU X may not, in fact, be feasible on CPU Y, for any reasonable definition of "feasible."

Note that the dateline there is June 2023 - whatever one thinks of LLMs, they are very different now, in March 2026.

Still 100% factually accurate.

My recent attempt to use Claude to write 65816 assembly while better, still produced code that wouldn't assemble, couldn't link, and won't work. It's taken significant work slowly elevating the code to usable.

For the details of my misadventure see: viewtopic.php?f=9&t=8577