One question that comes up pretty frequently among vintage computer enthusiasts is what to use as a MOS 6522 replacement. Commodore used this chip extensively, but so did others. There are suitable replacements in the form of second-source 65c22 chips, but not all of them work. Here’s what to use.
Commodore went out of business in 1994, and started winding down its chip production as early as 1992. But some of its designs were available through second sources, and the 6522 was one of them.

David Farquhar is a computer security professional, entrepreneur, and author. He has written professionally about computers since 1991, so he was writing about retro computers when they were still new. He has been working in IT professionally since 1994 and has specialized in vulnerability management since 2013. He holds Security+ and CISSP certifications. Today he blogs five times a week, mostly about retro computers and retro gaming covering the time period from 1975 to 2000.










