Panaplex display history

[tony duell]

> 
> LEDs themselves weren't all that much more costly than the typical pilot
> lamp.  I recall sending $1 cash to Montsanto and receiving 2 red (was
> there any other color?) LEDs in return in 1969.

Is there a good reason why filament lamps were used on minicomputer
front panels until the mid 1970s? Things like the PDP11/45, Philips P850, etc
all used filament bulbs, not LEDs.

-tony