30 May
2015
30 May
'15
11:29 a.m.
On 05/30/2015 12:40 PM, tony duell wrote:
Inertia! The 11/45 was designed before LEDs were available, and so they
never changed. To do it right, the PC board would have to be
re-designed to add the current limiting resistor. I did the mod on ours
by adding the resistor to the LED lead, as the bulbs were pretty tall
above the board.
Jon
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.