When was the first electronic bitmap sign invented? - Page 1
Forum section: electronics / general

author: Ampera
author_rank: Super Contributor
timestamp: January 19, 2020, 04:01:39 am
content: Sometimes you'll just come up with a question, maybe even one you've had for a while but suddenly decided, damn I need to know the answer to that one, it's got to have an interesting history.Put simply, I want to know what the first installed use of an electronic bitmap sign. This means any large format, think Times Square size, display which utilizes a grid of lights (or non-illuminating active elements), to automatically display information (text).Now Wikipedia proclaims the first *computerized* sign ever installed was the famous Westinghouse Sign. How computerized it actually was I believe it still up for minor debate, but regardless, Wikipedia claims this was completed in 1967, and construction was first initiated in 1966. Now that might be good enough, except just today I was watching some Beatles music videos on YouTube. In particular, I was watching the Vevo music video for Eight Days a Week, which has footage of the Beatles' concert in Shea Stadium.https://youtu.be/kle2xHhRHg4?t=107If you were to pause this video at around 1:46 and 1:47, you can see in soft focus, quite obviously, a bitmap text display in the background. Now I wouldn't say a bitmap screen must be computerized, so the Westinghouse Sign may have genuinely had a "computer" on it, with these signs simply having some other sort of controller logic, but that still leaves the original question. If this concert happened in 1965, and as of that point Shea Stadium had a large format bitmap sign, what was the first large format bitmap sign?Any ideas or insight would be helpful. I've tried to Google, but this question is particularly strange in that it seems like something someone should know, but I can't find that specific information documented anywhere. That being said, I haven't researched too hard, and thought I'd try here before digging through patents and such.

author: james_s
author_rank: Super Contributor
timestamp: January 19, 2020, 05:07:42 am
content: I don't remember what sign it was but I remember seeing an old photo somewhere of the controller for a scrolling text sign that used a paper(?) tape floating on a trough of mercury with a grid of contacts on top of the tape. Holes in the tape allowed the mercury to touch the contacts lighting the associated lamps.

author: bsdphk
author_rank: Regular Contributor
timestamp: January 19, 2020, 08:36:24 am
content: The worlds first scrolling electronic sign was invented by the danish engineer and inventor Viggo Jensen and put into operation in 1914, based on the principle of perforated papertape and using mercury as one of the contacts.Since 1926 the danish newspaper "Politiken" ran one of these "Light-Newspapers" on their building at Copenhagens "Rådhuspladsen", it was later upgraded to have multiple colors, green, red and yellow/white. These days it's been replaced with LEDs.There is a short movie-clip from 1939 here:https://www.danskkulturarv.dk/dr/bt-centralen-og-politikens-hus-lysavis/Viggo was a very prolific inventor, from variable speed motors for newspaper presses to what essentially became "Technicolor".

author: Ampera
author_rank: Super Contributor
timestamp: January 19, 2020, 03:24:42 pm
content: That's an absolutely ingenious design. Way simpler than how I'd have thought to make it, and definitely what I was looking for. Thanks for finding/knowing about this.

author: jmelson
author_rank: Super Contributor
timestamp: January 19, 2020, 06:43:22 pm
content: In about 1977 or so, I built an electronic controller for the "Nite Sign", a grid of incandescent lights suspended from a small aircraft or helicopter.The original control used a wide punched cloth tape dragged over a "bed of nails" in a mercury bath! They wanted to get rid of the mercury both for health hazards and because mercury eats aluminum. We used a 6800 demo board with a keypad and LED segment display and custome drivers, and the user could save and reload their messages via audio casette tape.Jon

author: Benta
author_rank: Super Contributor
timestamp: January 19, 2020, 08:05:25 pm
content: Quote from: jmelson on January 19, 2020, 06:43:22 pmLet me guess: MEK6800D2?Man, I remember those

author: james_s
author_rank: Super Contributor
timestamp: January 19, 2020, 08:08:54 pm
content: Yikes, I'm surprised they allowed such a large amount of mercury in an aircraft to begin with, especially in something like that where a spill seems entirely possible or even likely. I've seen what mercury does to aluminum and can imagine it would wreak havoc if it spilled on fresh scratch somewhere.It would be neat to see more details from that project though.

author: jmelson
author_rank: Super Contributor
timestamp: February 03, 2020, 09:11:19 pm
content: Quote from: Benta on January 19, 2020, 08:05:25 pmYes, that sounds exactly right! I still have a demo unit, I'll have to check.Jon

author: Ampera
author_rank: Super Contributor
timestamp: February 04, 2020, 05:22:47 pm
content: On the bright side, marquee plane exploding over the city will definitely make the nightly news, and your message will definitely be seen.

author: Axk
author_rank: Regular Contributor
timestamp: February 07, 2020, 07:00:05 pm
content: I wonder how they implemented showing the current time alternating on the same screen with the scrolling text like in this video:https://youtu.be/ZpXnEvW0XD0?t=1284(the General Motors ad starting at 21:24)And this scrolling text doesn't look like it is does with multiple separate bulbs, more like a projection (though it may be due to the low resolution of the film recording).

author: SL4P
author_rank: Super Contributor
timestamp: February 07, 2020, 11:17:47 pm
content: I’d guess that one of the earliest ‘computerised’matrix signs would have been an electromagnetic ‘flip disc’ arrangement.The power needed in the old days to get daylight readable illuminated pixels would have been enormous...?

author: Nusa
author_rank: Super Contributor
timestamp: February 08, 2020, 12:12:03 am
content: https://www.edn.com/motograph-news-bulletin-debuts-in-new-york-city-november-6-1928/QuoteThere's a picture in the link.Also see Frank C Reilly's patent, filed in 1913:https://patents.google.com/patent/US1119371A/enThe list of related patents of later state of the art is also interesting.

author: SL4P
author_rank: Super Contributor
timestamp: February 08, 2020, 12:30:32 am
content: Without reading that article, the consumption of that sign-wall must have been staggering -especially with the inefficient technologies of the time...Even multiplexed (incandescent?) would have been a huge undertaking, and the RF switching noise would have blocked radio reception for many blocks around!Non-multiplexed would have used more power than Las Vegas in the 80s !!

author: Nusa
author_rank: Super Contributor
timestamp: February 08, 2020, 01:20:34 am
content: Quote from: SL4P on February 08, 2020, 12:30:32 amHaving been to Las Vegas in the 1980's, I'm going to have to disagree with you on that. Most of major casinos, individually, likely beat that power budget with their exterior incandescent bulbs keeping the night away. Yay for the nearby Hoover Dam!

author: SL4P
author_rank: Super Contributor
timestamp: February 08, 2020, 01:34:14 am
content: QuoteShrewd observation.

author: james_s
author_rank: Super Contributor
timestamp: February 08, 2020, 03:30:07 am
content: Quote from: SL4P on February 08, 2020, 12:30:32 amI don't think it makes any difference if they're multiplexed or not, incandescent lamps respond to RMS power, much like thermal RF power meters, there are no external tricks you can use to make the filament get hotter with less power going into it. Additionally to multiplex incandescent you need a diode in series with each lamp which adds an additional penalty due to the forward drop.I remember reading years ago that the first programmable electronic sign on the side of some of the Goodyear blimps used 28V incandescent lamps controlled by a minicomputer in the gondola and needed a separate turbine APU slung underneath to power it.

author: bsdphk
author_rank: Regular Contributor
timestamp: February 08, 2020, 07:51:52 am
content: "Without reading that article, the consumption of that sign-wall must have been staggering"No, not really.The bulbs in the old papertape drive mechanisms were seldom even 5W each.6-The first one on "Politiken" had 149x9 bulbs so that would probably only be 6-7 kW fully lit.

author: Brent88
author_rank: Newbie
timestamp: February 09, 2020, 01:11:31 am
content: 1920s had readable bulb based signage

author: AlbertL
author_rank: Regular Contributor
timestamp: April 07, 2020, 05:05:33 pm
content: This film from 1935 looks at the workings of the giant Chevrolet sign in Chicago. It shows the control equipment for the Motograph and an animated explanation of how it functions.

author: LaserSteve
author_rank: Super Contributor
timestamp: April 08, 2020, 04:02:45 pm
content: The key to the motograph is using a inert gas filled lamp (Usually Krypton) for quick cooldown of the filament. Once upon a time I found myself getting a quote for 7,700 of the beasts.Steve

author: tooki
author_rank: Super Contributor
timestamp: April 11, 2020, 08:10:11 pm
content: Umm, aren'tallincandescent bulbs filled with inert gas?

author: james_s
author_rank: Super Contributor
timestamp: April 12, 2020, 12:50:33 am
content: Quote from: tooki on April 11, 2020, 08:10:11 pmNo, most under about 50 watts are vacuum filled. In small lamps with thin filaments the convective losses of a gas fill become more significant than the increased rate of tungsten evaporation you get with a vacuum filled lamp.

author: tooki
author_rank: Super Contributor
timestamp: April 12, 2020, 07:06:11 pm
content: Huh, ok! I guess that explains why when I was a minor (in the 80s/90s), better flashlight bulbs expressly said they were xenon or krypton filled. I guess the cooling from the gas either let them burn brighter, or keep them cooler to make them more shock resistant?

author: james_s
author_rank: Super Contributor
timestamp: April 12, 2020, 07:18:05 pm
content: Ordinary household lightbulbs typically use an argon/nitrogen mix fill, the increased pressure reduces the evaporation of tungsten in the same way that a pressure cooker raises the boiling point of the water within. This allows the filament to be run hotter, producing a brighter, more efficient lamp with higher color temperature while still achieving reasonable lifespan. Xenon and krypton accomplish the same thing but these gases are far less thermally conductive so they allow very small lamps to be gas filled without making them horribly inefficient (relative to vacuum) by excessive convective and conductive cooling of the tiny filaments. Krypton or xenon are very expensive compared to argon and nitrogen so combined with diminishing returns in larger/higher wattage bulbs it is not economical so it was rarely used.The hotter you burn a filament the more efficient the bulb, but the faster it burns out. Varying the voltage has a roughly linear effect on efficiency but an exponential effect on lamp life, hence the occasional bulb you hear about famously burning for 100+ years, or the once common photoflood bulbs that were rated to last 6 hours. Making a bulb last hundreds of thousands of hours is easy, but the reason it wasn't widely done is that the resulting bulb will be very inefficient. Contrary to the beliefs of some it was never a conspiracy to sell more bulbs, rather manufactures knew that electricity costs a lot more than bulbs so the typical 750-1,000 hours lifespan of a household incandescent lamp was settled on as a compromise between efficiency and lifespan.

author: @rt
author_rank: Super Contributor
timestamp: April 16, 2020, 04:17:24 am
content: Certainly not the oldest, but I still have a Z80 driven sign, with it’s associated DMA controller. How lovelyTwo colour LEDs ranged in alternating columns used to create 16 colours, so long as the text is moving.Different display, but this thread also reminded me of my favourite thread in the whole world:https://www.eevblog.com/forum/repair/progressive-gaming-neurizon-led-sign/?nowap

author: W-B_LiteBrite
author_rank: Newbie
timestamp: October 07, 2023, 12:03:40 am
content: QuoteWith all due respect, and from looking at key pictures and old films of the "motograph" in action, no way was it 14,800 bulbs.First of all, there are the dimensions of the building itself:43rd Street - 20' (240")Broadway - 143' (1,716")42nd Street - 58' 4-1/8" (700.125")Seventh Avenue - 137' 11-3/4" (1,655.75")Also, several photos were taken of the 43rd Street side during World War II when it was not running. The "Motograph" (as it was originally known) was built 12 rows high on a 60" high ribbon (thus each row was separated by 4.5"). On 43rd Street, 720 bulbs were on that side. Or an average of 60 per row. Meaning that the vertical columns were spaced 4" apart. 18 bulbs were missing from the bottom left side, and 6 from the top right - all to conform that side to the angles at which they were built and positioned (about 9.4 degrees, from what I could tell in terms of the slant).Thus, by such measurements, it is estimated that the Broadway side had a total of 5,149 bulbs (>429 average per row), the 42nd Street side 2,103 ( > 175 average per row) and the Seventh Avenue side 4,963 ( < 414 average per row). The grand total of bulbs, give or take:12,935The other factor, in studying old photos and films, is how many characters were on each side at one time. Close-up, character spacing was about 12.5 bulbs, give or take. (The way the characters moved seemed reminiscent of the old interlacing on analogue TV's.) Thus by that factor, there was an average of:- 4.8 characters on 43rd Street- 34.32 characters on Broadway- 14 characters on 42nd Street- 33.12 characters on Seventh AvenueAs the headlines passed, on each corner one letter disappeared for a bit. This was where the ornaments connecting each side were mounted.If the four sides were attached end to end, they would consitute 1,078 average rows for a total of 359' 4". On each corner as the message advanced, about one character was missing; if accounted for, that would add 16 feet (4 feet per side) to the figure, thus the total would be about 375' 4". (That's on the level where the top row was; going to the furthest up it'd be about 5' max per side, thus close to the 380' figure cited.)On the 1997 updated (Mark III) zipper around the building, there may have been 227,200 LED's, but I counted 22,720 pixels total. Meaning, 10 LED's per pixel. That used Daktronics Sans Serif 16.But the Mark II zipper, my personal favorite, used from 1965 to 1997, used the same dimensions for bulb spacing (4" between columns, 4.5" between rows), 11 rows high on a continuous band measuring 57" tall. Its initial controls - operated by Life magazine from 1965 to 1971 - were from Chicago-based Naxon Telesign with which sign-maker Douglas Leigh had a long relationship (developed in part because of Artkraft Strauss' exclusive arrangement with Trans-Lux whose zipper controls were used for many a "Flashcast" or "Adcast" traveling message sign on Artkraft billboards up and down the Square). For this the company devised a round display font for use on zippers like the one being built not only there, but also atop the Walgreens building on the corner of State and Randolph Streets in Chicago. (Before then, they used a square / boxy font that had been in use on all their machines built since 1939.) The Times Square "Mark II" zipper consisted of 12,408 bulbs - or 1,128 per row. Three sides had the Life logo flashing in-between headlines (after Life dropped out and Reuters began operating it later in '71 for a 6-year period, the red bulbs were taken out and replaced with other A19 inside-frosted bulbs, making them look like Velcro add-ons). The bulbs used to flash the headlines at the start were (apparently) 30 watt (definitely) A21 reflector bulbs. From about 1972 to '77 they used a Digital Equipment Corporation-derived dot matrix font that was used on Reuters' Extel 70 teleprinters (see below - would anyone know the exact name of this predecessor to the RO3-2513 font used on Apple II computer monitors?). Then starting in 1986 when New York Newsday took over operation, they began using an early Daktronics Venus system with Sans Serif 7 for the headlines . . . and Fixed Width 7 for the time and temperature checks.

author: jonpaul
author_rank: Super Contributor
timestamp: October 07, 2023, 05:20:41 am
content: 1928:Times Square Manhattan NYCNY Times newsIncandescent lamps and relays.https://www.timessquarenyc.org/history-of-times-squareJon

author: tooki
author_rank: Super Contributor
timestamp: October 07, 2023, 07:10:36 am
content: Quote from: jonpaul on October 07, 2023, 05:20:41 amThe link in reply #11 above contains a much larger version of that photo, rather than the uselessly small thumbnail you attached.

author: W-B_LiteBrite
author_rank: Newbie
timestamp: October 07, 2023, 11:55:50 am
content: I also wish to note that on the Smithsonian Institution website relating to Douglas Leigh's papers and photos, a picture of the Times Square zipper's 1965-71 Chicago sister (see below) had the caption misidentify the period taken as 1940-45, though clearly the Life logo as it looked from 1961 to its demise as a weekly in 1972 was clearly in evidence (as was the round Telesign display type). Maybe they confused the pic with that of the World War II-era zipper across the street (at Seventh and 42nd, atop the Rialto Theatre) that flashed news headlines in the daytime per dimout requirements - but was mounted by Artkraft Strauss and its zipper controls from Trans-Lux, and operated by Coca-Cola and the radio station then known as WJZ, now WABC. (Some pics taken from the SE corner of 42nd and Broadway facing northwest on D-Day showed this "other" zipper in operation, across from The Times' as their headlines were flashing.)

author: AlbertL
author_rank: Regular Contributor
timestamp: October 09, 2023, 03:59:29 pm
content: This film shows the paper-tape equipment for the Motograph on the giant Chevrolet sign in Chicago:

author: ebastler
author_rank: Super Contributor
timestamp: October 09, 2023, 04:34:15 pm
content: Quote from: AlbertL on October 09, 2023, 03:59:29 pmLooks almost like the great clip posted by a guy named AlbertL in reply #18, 3.5 years ago!

author: W-B_LiteBrite
author_rank: Newbie
timestamp: April 11, 2025, 10:50:14 pm
content: Quote from: Ampera on January 19, 2020, 04:01:39 amMay or may not have been the first, but the sign at Shea was built by General Indicator Corp.'s All-American Scoreboards division and first put in use at the Mets' first season there - 1964. Their font was similar to what Stewart-Warner had.

author: W-B_LiteBrite
author_rank: Newbie
timestamp: May 19, 2025, 06:41:30 pm
content: As to the Motograph, I did a slight miscalculation. Instead of 15 bulbs missing on the left end of the Seventh Avenue side, there were five (only seven shown on the first column). And based on the measurements of the building from end to end on that side, the bulb count from end to end would have been ~4,963 bulbs (rather than 4,965), thus the total would actually have been ~12,934 bulbs. But in any case . . . no way was the tally actually 14,800. With the building measurements, Motograph row height and the spacing of the columns, it would have been impossible to attain such a high number.I counted a total of 175 full panels (24" x 60", 72 bulbs in a 6 x 12 arrangement) and 7 partial ones - two on each end of the 43rd Street, Broadway and 42nd Street sides, only one on Seventh Avenue on the left.

author: TimFox
author_rank: Super Contributor
timestamp: May 19, 2025, 07:52:55 pm
content: As a kid, I found a stash of prewar Popular Mechanics and similar magazines collected by my uncle.I remember a short article featuring a wall of light-bulb pixels controlled by another wall of photocells (probably gas-filled, driving relays) so that a human could dance in front of the “electric eyes” and be represented by the lights.

author: rdenney
author_rank: Regular Contributor
timestamp: May 22, 2025, 03:13:41 pm
content: All these Motograph signs were electromechanical, not electronic. They used paper tapes or conveyor-driven switch contactors, and the messages they displayed were mechanically produced.The question was the first "electronic bitmap" sign, which seems to me to require a matrix of on-off instruction stored electronically. I haven't been able to find good info on this, but it would appear that the first large-scale computer-controlled bitmapped display was the Astrolite scoreboard installed in the Astrodome in Houston in 1965. The central part of the scoreboard complex was a bit-mapped display of about 30 by 40 feet that used incandescent bulbs and was computer-controlled to show animations and real-time messages.Character-matrix signs such as those used on lighted scoreboard were older, and were probably switched from electromechanical patterns, not from electronic storage prior to the 60's.The first freeway-management signs were used on the New Jersey Turnpike in the 50's, but those were "changeable" message signs, not "variable" message signs, and could only light or not light specific words that were formed in neon. These were in use until a little over ten years ago. Other forms of changeable message signs were used on freeways going back to the 40's, using rotating drums with a fixed and limited set of messages on them, that were remotely switched. The first true variable-message signs that were bitmapped (but still character-based) were used in the late 60's, though I can't find a concrete example of those before the Santa Monica Freeway surveillance, communication and control system that was built in 1972.The use of electromechanical displays with flip disks or rotating triface targets also date to the 70's.The first scoreboard that could show video was in 1970's, and the first to show color video was actually quite a bit later.Japan switched to fully bitmapped graphic displays on freeway signs in the 80's. Prior to that, they used fixed bulb signs depicting the main road network in Tokyo that would be lighted with different colors to show motorists current conditions on the freeways. These became computer-controlled bitmapped displays in the 80's, mostly showing the same thing. Character-matrix signs using neon and later LED's followed up these large graphic displays show show travel times to specific downstream landmarks.Bulb-matrix, flip-disk, fiber-optic and LED technology were competing for traffic control signs up until the early 2000's, when LEDs took over.Back to the Astrodome--they built an LED-based color scoreboard to replace the original in 1988. I'm sure it was not the first, but it was pretty early.But the main answer is: The first electronically controlled bit-mapped sign dates to the 60's.Rick "marched around in the Astrodome as a Boy Scout the year it opened" Denney