Panaplex display history

Johnny Billquist bqt at
Sat May 30 15:52:45 CDT 2015

On 2015-05-30 19:40, tony duell wrote:
>> 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.

By the 11/70, as well as the PDP-8/M and PDP-8/F DEC had switched to 
LEDs. So they switched before 1975.


Johnny Billquist                  || "I'm on a bus
                                   ||  on a psychedelic trip
email: bqt at             ||  Reading murder books
pdp is alive!                     ||  tryin' to stay hip" - B. Idol

More information about the cctech mailing list