Philips PM5540
The Philips PM5540 was an early electronic video signal generator, which generated a monochrome test card that is considered to be a black-and-white predecessor of the widely used Philips PM5544 and the latter's related family of Philips circle test patterns. The content and layout of the pattern, as well as the generator, was designed and made by Danish engineer Finn Hendil (1939–2011) at the Philips TV & Test Equipment laboratory in Amager, south of Copenhagen in 1965–66.