Panaplex display history

[tony duell]

> JOOI, does anyone know when Panaplex 7-segment displays started going the
> way of the dodo, to be replaced with LED displays (and, on the back of
> that, what were the advantages of a Panaplex-type display over an LED one?)

It would appear that in the early 1970s LEDs were very expensive. I have been looking at the 
HP5930x HPIB units and in many cases the status indicators (power on, listening, etc) are 
filament bulbs + driver transistors. I can think of no advantage to using a filament bulb in this
application other than possibly cost. The 59304, which has a Panaplex display and therefore
the HV supply to drive it, uses neon bulbs (NE2 sort of thing) as status indicators.

-tony