I was told by Leonard Tramiel (who was my manager at Atari for a while) that the world record for a production 6502 was 25Mhz. This was demonstrated one Friday evening, some time after the beer fridge had been opened in one of the labs.<p>I don't know if they applied any kind of external cooling, or what the benchmark was. Probably it was "keep cranking up the clock until pins stop wiggling or smoke comes out." Not very scientific, but quite entertaining.
It's an interesting article, but...<p>Better title: Clocking a 6502 Simulator to 15 GHz. There are multiple efforts to recreate the physical 6502 CPU on modern hardware, this is not one of them and should not be confused with that.
I realize I'm late to the party, but I've really been enjoying Ben Eater's series on building a simple computer with a 6502.<p><a href="https://www.youtube.com/playlist?list=PLowKtXNTBypFbtuVMUVXNR0z1mu7dp7eH" rel="nofollow">https://www.youtube.com/playlist?list=PLowKtXNTBypFbtuVMUVXN...</a>
After stumbling on Ben Eaters “Hello world from scratch” [1] I went out and bought the cpu some parts and breadboards. The chip is only a few dollars. It is highly recommended if you want to dive down into computers and digital logic on first principles. Also great fun to get a break from all the screens and layers upon layers of software that I have to deal with daily.<p>1. <a href="https://youtu.be/LnzuMJLZRdU" rel="nofollow">https://youtu.be/LnzuMJLZRdU</a>
For more "very fast simple CPU" architecture, see <i>50,000,000,000 Instructions Per Second: Design and Implementation of a 256-Core BrainFuck Computer</i>: <a href="https://people.csail.mit.edu/wjun/papers/sigtbd16.pdf" rel="nofollow">https://people.csail.mit.edu/wjun/papers/sigtbd16.pdf</a>
Huh... I hadn't considered it before, but Bender's brain <i>could</i> actually be a 6502, just being run at an insanely high clock speed. A few petahertz should be able to handle the AI involved, no?<p>Planck time is like 10^-43 seconds, so there's lots of room to divvy up a second for more processing power given advanced technologies...
It would be interesting to compare this project to simply converting 6502 assembly into LLVM IR, and letting clangs optimization passes work their magic.<p>Obviously self modifying code would be hard to handle, but every other case ought to work, and the auto-vectorization ought to do amazing things to some loop-heavy code.
To solve the FF page wrapping problem, I wonder if it would work to double-map each 6502 page to x64 host pages side by side. I assume the word read at FF would straddle the two mapped pages effectively reading the second byte at 00. You'd have to map to host page boundaries of course and probably offset all reads/writes to the end of the host page at $3F00.
I believe VMware without hardware support for virtualisation also falls back to "binary translation" and similarly gets tripped by SMC - I don't recall the details right now but one of the ways to detect it was to modify an instruction in an obscure way that the developers had forgotten about.
The Mega65 runs a 6502 at 50Mhz compatible with the Commodore 65 plus C64 mode. <a href="http://mega65.org" rel="nofollow">http://mega65.org</a>