From: CLASSICCMP(a)trailing-edge.com (Tim Shoppa Email: shoppa(a)trailing-edge.com) Have you heard of a check valve? No doubt it's _called_ one (where electron tubes are called valves). I can cite several worse misnomers in popular use. On the subject of unusual display devices, as I recall, the Univac 422, a training computer (transistors, 512 15-bit words of core memory, with paper tape and (modified) Remington Rand typewriter for I/O) from the 1960's, used blue-green vacuum fluorescent indicators on its front panel, to display register contents. Not digital displays in the modern sense, they were just blue-green lamps. I assume that they were chosen for their ability to be controlled by transistors which were unable to cope with the voltages of neon glow lamps or the current of incandescent lamps. I never saw them on anything else. I don't doubt that they had better long-term reliability than the SCR-driven incandescent lamps in the console display of the IBM 1130 CPU. ------------------------------------------------------------------------ Steven M. Schweda (+1) 651-645-9249 (voice, home) 1630 Marshall Avenue #8 (+1) 612-754-2636 (voice, work) Saint Paul MN 55104-6225 (+1) 612-754-6302 (facsimile, work) sms(a)antinode.org sms(a)provis.com (work)