Digging Into The 6502

The 6502 holds a place of honor amongst the Apple II faithful only slightly lower than that occupied by Steve Wozniak. Apple likes to conclude their press releases with a brief company history that begins with the phrase, “Apple ignited the personal computer revolution in the 1970s with the Apple II”. Well, whether or not the personal computer revolution was truly ignited by Apple may be up for dispute amongst retro computing enthusiasts, but there is no doubt that it was the 6502 from MOS Technology that ignited the imagination of Woz to create the first Apple-1, and later the Apple II. It was as important to Apple as the internal combustion engine was to Henry Ford.

According to an article on Techworld (and reprinted on MacUser), digital archeologists Greg James, Barry Silverman, and Brian Silverman have literally taken the 6502 processor apart, layer by layer. Using this information, they have created a Javascript animation of the function of the 6502, which shows what is happening within the chip as a short machine language program is executed. You can view this animation here at visual6502.org.

Screen shot of part of the visual 6502

Addendum: Thanks to Ken Gagne’s quick eye, here are two more articles about this:



Leave a Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.