29 Feb
2008
29 Feb
'08
3:45 p.m.
Does anyone know when seven segment displays first appeared on the scene?
Presumably the first ones were VF, and LED came later?
There were some filament ones -- 7 long filaments in the obviosu pattern,
in an evacuated envelope. Some looked like vavles (but were generally
wire-ended), others were ina flatter package, looking a bit like an IC.
And of course there were gass discharge 7-segment displays. The obvious
one is the Panaplex, but I think ones in valve-shaped envelops also existed
And don't forget that the HP9100 calculator (1967-ish) drew the vectors
for 7 segment digits on a CRT screen.
-tony