Computer history, restoring vintage computers, IC reverse engineering, and whatever Update: It turns out my 7805 isn't counterfeit. eclectro did an in-depth search (details on reddit) and found an old 7805 datasheet from Thomson Semiconductors that exactly matches my chip. And Thomson is the T in STMicroelectronics. So that explains how this die ended up with a ST label. Under a microscope, a sili