6502 visual simulator

This has to be one of the coolest retro-hardware projects I’ve seen in a while. It’s a transistor-level simulator of the 6502, written in Javascript, that visually simulates the device based on its original mask pattern — painstakingly reverse-engineered from high-resolution die photographs. Fortunately, mask works have a “sane” copyright term of only a decade, so cool projects like this are facilitated through such reasonable limitations on copyright lifetimes.

Click the image above to take you to the live simulator. As it runs, the wires dynamically change color on a cycle-by-cycle basis as the logic states of each wire update.

It makes my head spin to think that the CPU from the first real computer I used, the Apple II, is now simulateable at the mask level as a browser plug-in. Nothing to install, and it’s Open-licensed. How far we have come…a little more than a decade ago, completing a project like this would have resulted in a couple PhDs being awarded, or regarded as trade secret by some big EDA vendor. This is just unreal…but very cool!

4 Responses to “6502 visual simulator”

  1. [...] The mask layers are drawn using canvas, a great demo of what that element is capable of. Read Bunny’s comments as well of course. This entry was posted in Uncategorized. Bookmark the permalink. ← Wow, [...]

  2. [...] [via Bunnie studios] [...]

  3. I love your blog Bunnie. Please keep posting.

  4. That simulation gave me a headache. I’m thinking on fallout computers right now, prewar. Funny, still interesting.