I saw this on TV twice, possibly on Discovery channel. A crowd was celebrating the end of WWII in the street and the reason for jubilation was displayed in giant scrolling text on the side of a building. Certain factors prevented me from discerning the type of display used - 1) the part showing the display was brief, 2) it was an old B&W film, 3) delayed reaction on my part both times.
I've searched for it from time to time without success. It's unlikely that the technology for a scrolling electronic display existed then. So what was it? A banner?
BTW I love the photo of a sailor kissing a girl that day. I think it's one of the great photos of all time.
Hmm I vaguely remember rolling text along the side of some building in times square. (NYC) I'm not sure what time that would have been... nor what building it was on.
Probably lamps controlled by contacts sensing holes in a moving paper-tape or cardboard strip. The tape can have any pattern to be shown on the lamps. It would even allow tiny drawings and proportional fonts.
It is the same basic idea as street organs with a cardboard 'book', although these are pneumatic.
tirsdag den 21. april 2020 kl. 14.23.22 UTC+2 skrev Pimpom:
as a far as I know the worlds first scrolling electronic sign was invented by the danish engineer and inventor Viggo Jensen and put into operation in 1914, it was controlled using paper tape and mercury
I saw a video of the equipment. it was fully mechanical, with groups of steel balls rolling down rails to turn on the lamps in sequence. This both created the pixels, but allowed for smooth motion.
The movie theater is advertising "A Damsel in Distress" with Fred Astaire and George Burns as a new release which places this film around Christmas, 1937.
The hotel Astor had hired a new bus driver and instructed him to meet all incoming trains and announce at the depot in a very loud voice, ?Free bus to the hotel Astor!?
Upon his arrival at the station, however, he became confused at all the noise and hub-bub and started shouting as follows. ?Free hotel at the bust your Astor, I mean, Free ass at the Hotel Bastard, I mean, Freeze your ass at the Hotel Buster, I mean Squeeze your bust at the Hotel Faster, I mean, Bust your ass at the Hotel Freezer...oh hell just take a cab.?
For very large signs I expect they didn't have the lamp-relays connected directly to the sequencing apparatus; perhaps AC relay coils were switched by gas thyratrons from low-voltage control signal, another relatively novel invention at the time
I can confirm that the sign over the Hippodrome theatre in Bristol used the paper and mercury system well into the 1970. I am related to the daughter of the man who used to operate it - he died of mercury poisoning many years ago.
The system comprised a long strip of paper with the required text punched as a series of holes, it was dragged along a flat-bottomed trough by being unwound from a free roller and wound up by a powered roller at the opposite end. It was arranged to droop between the two rollers and a puddle of mercury sat on top of the dip.
The surface tension of the mercury prevented it from falling through the holes, but it formed a meniscus projecting below the bottom of the paper. These projecting globules made contact with studs let into the insulated bottom of the trough in a pattern corresponding with the lamps on the display board outside.
I understand that 240v mains was used to power the lamps, because their filaments had to be thin with little thermal inertia to prevent smearing of the message. This resulted in constant sparking, which filled the air in the machine room with mercury vapour.
Lamps frquently needed replacement and this was done by the operator from a catwalk along the front of the building, high safety rails would have been visually unattractive, so the were omitted.
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~ Adrian Tuddenham ~
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Not just a lot more lights. A lot more processing too. Running lights - the kind you see on those signs - need only three sets of lamps lit in sequence. Text needs a more complex operation.
You must be thinking in terms of modern technology that has evolved, been refined and passed on for decades. The people who developed those displays must have had to invent them from scratch.
Think how much processing a DMP needs to control each pin according to the input.
No... we had movies. One frame at a time. We had blinking lights... it's not to hard to imagine moving blinking lights. How they did it might be interesting. George H.
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