We had one of the first class of HP3000 minicomputers, which was both highly advanced, with it's stack architecture and variable length memory segmentation, but also very disappointing. But on the flashing lights front, the first design class did not disappoint (see console in upper right quadrant - lots of LEDS - which were new and only red in those days - and paddle switches): http://www.hpmuseum.net/images/3000_2615A_1973-25.jpg