Apple ][ PS and more - Ken Shirriff's blog

Shoppa, Tim tshoppa at
Thu Jun 15 12:49:17 CDT 2017

I just recently discovered Ken Shirriff's blog which has a lot of interesting stuff.

e.g. discusses not just outlandish claims about the Apple II power supply, but also the evolution of switching power supplies in computers from the 60's through today (slight detour, possibly false detour, into scope supply design!) Very good rundown with patent numbers and a "hall of fame" of switching power supply designers.

Other fun stuff he goes through below. The second one below shows a punch card with CHM logo so I'm guessing he's a regular out there?

*         Reverse Engineering the 76477 "Space Invaders" sound effect chip from die photos

*         1950's tax preparation: plugboard programming with an IBM 403 Accounting Machine

*         Inside the vintage 74181 ALU chip: how it works and why it's so strange

Tim N3QE

More information about the cctech mailing list