Christiaan008
2 HN recommenders · recommended in 4 months, 2014–2021
51:57 · 477K views · Jan 10, 2011
Michael Steil's 27c3 talk on reverse engineering the MOS 6502 from die shots into a transistor-level simulation, as in the Visual6502 project. It covers going from chip package to a digital model.
HN recommends it as a great walkthrough of chip reverse engineering and the story of Visual 6502.
4 comments from Hacker News
There's a lot of information about reverse engineering some of the older CPUs around e.g. the MOS6502 (NES, Apple II, C64, etc). This is a great presentation showing how this CPU is reverse engineered: this video Basically it comes down to the fact that you can't really hide transistors and ultimately that's something you can reconstruct. It sounds like a lot of work, and it is, but if you do it you can perfectly emulate a chip. If you can dig out non volatile memory then potentially you have the firmware. Once someone has their hands on that it'll be broken, almost guaranteed, as it becomes a software problem. Lots of people are very good at assembly hacking.
If you have no experience in digital electronics at all, I would actually start with a book like Code by Charles Petzold. It's a pop-science book about electronics and goes from light bulbs and switches to simple logic blocks like adders. It covers the basic building blocks of virtually every cpu in existence - how to turn transistors into calculators. It's well written and provides some context to otherwise pretty dry textbooks. There is quite a bit of difference between how an FPGA works and is programmed versus a totally custom chip. You could also take a look at reverse engineering walkthroughs eg Ken Shirrif has a few on his blog. Nand2tetris is another good thing to look at. Finally, reverse engineering the MOS6502: this video
Here's a nice talk video covering the story from the origins of the 6502 to the Visual 6502 (but not the wasm Remix): this video .
It used the MOS 6502 CPU, which was also used for the Apple I, Apple II, the Commodores and Atari and Nintendo (NES, SNES) game consoles! this video [LINK] [LINK]