[Piotr Patek] ran into this issue when he obtained an Elektronika MK-85 programmable calculator with a broken CPU. Unable to find a replacement, he decided instead to build a pin-compatible CPU ...

Why not spruce up the scientific calculator of yore with the wonders of modern microcontrollers? While you won’t be able to use Sci-Calc on a standardized test, this classy calculator will let ...