Screen Accurate ECTO-1A Dot Matrix LED Sign (Reference)

[prodestrian]

I’ve been collecting reference material for a while because there seems to be confusion about what the ECTO-1A Dot Matrix LED signs actually show, to the point where the recently released Haslab ECTO-1A contains multiple errors.

I figured it’s probably time to share what I have with the community and see if we can work together to fill in the blanks. I realise there have been other attempts to document this in the past, but none of them seemed correct.

This Reddit thread is probably the closest so far, but it’s far from accurate.

The incredible ECTO-1A New Jersey is also close but misses an entire chunk of the sequence too (maybe once this thread is finished I’ll send the details over and see if they want to roll out an update).

To keep this easy to read I think we can attack this in a few passes.

1. Hardware - The sign itself
2. Text - What does it actually say?
3. Sequence - In what order?
4. Animations & Timing - How it’s presented

Where possible I’ll try to include screenshots, and make it clear where the gaps are in the reference material.

Hardware

According to the GBFans wiki the sign is approximately 76"x 10" (193x25cm).

The sign is made up of a matrix of red and green LEDs (or at least I assume they’re LEDs, not incandescent bulbs).

Each “pixel” is made of 4 individual LEDs, I don’t believe these are ever operated independently.

Here are some close-ups:

As you can see, the green pixels sit slightly lower than the red pixels, which is clearly visible in the film when both red and green pixels are shown at the same time (note how the “BACK” text doesn’t align with “WE’RE”):

The matrix contains exactly 80 pixels across, by 7 pixels down.

This is a total of 560 pixels of each colour.

That’s 1120 total pixels, each containing 4 LEDs, bringing us to 4480 individual LEDs per sign.

Based on the Wiki dimensions, we can estimate that the sign uses 5mm or 6mm LEDs (this is unconfirmed).

As far as I can tell from all my reference material, the two signs always show the same thing at the same time (they’re mirrored). It’s likely they’re connected to the same controller.

Next, onto the Text…

[prodestrian]

The Text

Based on all the reference material I’ve found, here’s every individual frame of text I’ve been able to document.

Note that this completely ignores the colours, animations, timings, or sequence. Some of these frames seem to be repeated more than once. We’ll deal with that later, for now we just want to lock down everything the sign says rather than when/how it says it.

**- GHOSTBUSTERS

• FOR HIRE…
• WE’RE READY
• TO BELIEVE YOU
• CALL JL5-2020
• WE’RE BACK
• WHO YA
• GONNA
• CALL?
• US!**

GHOSTBUSTERS

FOR HIRE…

WE’RE READY

TO BELIEVE YOU

CALL JL5-2020

WE’RE BACK

WHO YA

GONNA

CALL?

US!

NOTES

1. “WE’RE BACK” has an apostrophe. Multiple model kits including the HasLab got this wrong.

[prodestrian]

Sequence

This is where things get significantly less clear, because (as far as I know) there isn’t any uninterrupted footage of the sign.

We’ve all seen the transition from “GHOSTBUSTERS” to “FOR HIRE…” during the montage scene.

We can also see in the montage (if you look carefully) the transition from “WE’RE READY” to “TO BELIEVE YOU” (although not on the same sign at the same time, it transitions while the car is flying around the corner).

When the ECTO-1A arrives at the museum the first time, we can see “CALL JL5-2020” transition to “GHOSTBUSTERS”.

When it arrives at the slime-covered museum at the end, it says “FOR HIRE…”, but then I’m 90% confident it transitions to “WE’RE READY”

As it gets closer, we see it transition from “US!” to “CALL JL5-2020”, and then to “GHOSTBUSTERS”:

As the Ghostbusters approach the slime, we see it transition from “TO BELIEVE YOU” to “CALL JL5-2020”:

During the deleted scene where Hardemeyer gets sucked into the slime, we get a very long shot showing “WE’RE BACK” transition to “WHO YA”, then “GONNA”, then “CALL?”, then “US!”, then “CALL JL5-2020”, then “GHOSTBUSTERS”.

UPDATE: This matches the Getty Images video from the GB2 premiere.

So, I think all this reveals some important information. We can see both “TO BELIEVE YOU” and “US!” transition into “CALL JL5-2020”. That means this frame is shown twice in the sequence.

We’ve only ever seen “CALL JL5-2020” transition to “GHOSTBUSTERS”, so I’d wager that “GHOSTBUSTERS” always follows.

Further supporting this is the fact that I’ve seen two different animation styles for “GHOSTBUSTERS”. There’s one where it alternately cycles between red and green text, and another where it’s green text but shows a “shimmer” effect. We see it briefly when Venkman gets out of the ECTO after it arrives at the slime covered museum. We also see it in the deleted scene after Hardemeyer gets pulled into the slime:

But then there’s this shot as Hardemeyer is walking to the slime, where “GHOSTBUSTERS” is red and shimmers out (so I’m not really sure where that fits in):

EDIT: Another compilation of deleted scenes has a shot from slightly before the above one, where you can see the “GHOSTBUSTERS” text animating from red to green multiple times (and flipping upside down?) before landing on green, where presumably it then shimmers out (I haven’t had time to try to combine the two shots but I should do that):

We’ve seen it go from “GHOSTBUSTERS” to “FOR HIRE” without shimmering, so my guess is that the shimmer effect leads into “WE’RE BACK” (it fits the sequence but I can’t confirm it).

EDIT 2: This video has a blurry but close-up shot of the shimmer effect at 1:05:

https://www.youtube.com/watch?v=WjImnABkJAs

It seems to show “GHOSTBUSTERS”, then shimmer, then “GHOSTBUSTERS” again. There’s another shot of this at 1:44 but it cuts away for a bit, by the time Ray/Peter walk back to the car it’s showing “WE’RE BACK”

Here’s the draft sequence I’m working with (not final!):

1. GHOSTBUSTERS
2. FOR HIRE…
3. WE’RE READY
4. TO BELIEVE YOU
5. CALL JL5-2020
6. GHOSTBUSTERS
7. WE’RE BACK
8. WHO YA
9. GONNA
10. CALL?
11. US!
12. CALL JL5-2020

(and then back to the start)

[ZeroSum]

I’ve been working on this too. I’m happy to share my results. Here is an example. Still a work in progress.

[winston-smith]

This is excellent work. I am very impressed by your attention to detail.

[ZeroSum]

My goal is to be able to print these out on acetate as replacements for the Haslab LED signs. I don’t have any experience with printing on acetate but hopefully it will result in something translucent enough to let just enough light shine through, but not too much.

I’m playing about with different variations. The first one is just the lit up LEDs. The 2nd is the lit up LEDs plus a faint appearance of the unlit LEDs. The 3rd is the lit up LEDs with an added glow, plus the unlit LEDs. Not shown is a version that is the lit up LEDs without the unlit LEDs - just a black background. I like the third one, myself.

Apologies if I’m derailing the intent of this thread. Let me know and I’ll start a separate thread if you wish.

[kingpin]

The video quality is poor, but this footage from the Ghostbusters II premier may be helpful:

https://www.youtube.com/watch?v=O-kQJWrqLvM

Edit: Found the original GettyImages listing, which is slightly better in quality: LINK

[prodestrian]

@ZeroSum post_id=5008039 time=1768216167 user_id=53413

My goal is to be able to print these out on acetate as replacements for the Haslab LED signs. I don’t have any experience with printing on acetate but hopefully it will result in something translucent enough to let just enough light shine through, but not too much.

Apologies if I’m derailing the intent of this thread. Let me know and I’ll start a separate thread if you wish.

They look great! I think technically this is outside the scope of the thread, it’s supposed to be a reference rather than a specific build (for example if someone wants to build a working full sized LED display for their ECTO). In a dedicated thread you’ll be able to discuss your project with Haslab owners. But we’ll want to have some examples of the exact pixel placements, and those definitely help.

If only we had better reference…

@Kingpin

The video quality is poor, but this footage from the Ghostbusters II premier may be helpful:

https://www.youtube.com/watch?v=O-kQJWrqLvM

Edit: Found the original GettyImages listing, which is slightly better in quality: LINK

Seriously, the number of different search combinations I tried, and somehow this never showed up in any of the results! This is exactly what we need. I had already started working on a spreadsheet so this evening I’ll use this to go in and fill in all the gaps in the sequence, then start stepping through the video frame-by-frame to get relevant screenshots so I can update my previous posts. It doesn’t show the complete sequence but combined with what we’ve been able to extract from the film I think we now have everything we need, it certainly clarifies most of what was missing/obscured in the film.

Outstanding work!

[ZeroSum]

@Kingpin post_id=5008042 time=1768231324 user_id=76

The video quality is poor, but this footage from the Ghostbusters II premier may be helpful:

https://www.youtube.com/watch?v=O-kQJWrqLvM

Edit: Found the original GettyImages listing, which is slightly better in quality: LINK

Some great references in that vid. I notice that the preview Getty provides is 576 x 432 whereas the video you can buy from Getty is 720x576. That would provide slightly better image quality but it’s expensive and there’s every chance Getty just upscaled the original SD video to 720, providing no genuine improvement.

In any case, here’s some screengrabs from the video for convenience:

[ZeroSum]

@prodestrian post_id=5008046 time=1768253595 user_id=50434

@ZeroSum post_id=5008039 time=1768216167 user_id=53413

My goal is to be able to print these out on acetate as replacements for the Haslab LED signs. I don’t have any experience with printing on acetate but hopefully it will result in something translucent enough to let just enough light shine through, but not too much.

Apologies if I’m derailing the intent of this thread. Let me know and I’ll start a separate thread if you wish.

They look great! I think technically this is outside the scope of the thread, it’s supposed to be a reference rather than a specific build (for example if someone wants to build a working full sized LED display for their ECTO). In a dedicated thread you’ll be able to discuss your project with Haslab owners. But we’ll want to have some examples of the exact pixel placements, and those definitely help.

If only we had better reference…

Fair. Here’s a scan from a book showing an accurate pixel placement for WE’RE BACK:

If it’s useful, I can provide a pixel map to show the exact pixel placement for each variation of wording. As an example (you’ll have to open it in imgur to enlarge it to a useful size):

[prodestrian]

@ZeroSum post_id=5008051 time=1768275197 user_id=53413

If it’s useful, I can provide a pixel map to show the exact pixel placement for each variation of wording. As an example (you’ll have to open it in imgur to enlarge it to a useful size):

That’s very useful, thanks! I haven’t yet updated my posts above, so I’ll try to get on that soon. Thanks for the screenshots too.

I think I’ll split this off into a separate thread soon so I keep this as a pure reference thread, but I’ve started working on a sign generator app (it’ll be web-based).

What I’d really like is to be able to convert every frame/word into code which can be easily imported into electronics projects.

Every pixel has 4 possible states:

1. Off/Black
2. Red
3. Green
4. Red + Green
   So we’d be able to represent each frame using an array of 560 numbers.

For example:

[0,0,0,0,1,0,1,2,2,3,3,1,<truncated>]

would give us this:

This can be easily converted into other data formats (JSON, hex, whatever is needed).

To start, I used a reference screenshot and recreated the LED placements using a HTML canvas:

I had to scale everything down proportionally to fit on my screen. At the moment 80x7 columns/rows takes up about 2000px, there’s room for improvement but it’s enough to prototype with for now.

Here’s the generated grid:

And here’s a demo recording. I can click on each pixel to cycle through the four states (red => green => red/green => off).

I can also click on the Randomize button which quickly sets all the pixels to a random state, mainly so I could test whether the code is performant enough to be able to eventually do animations (it seems pretty efficient).

It’ll also be fairly easy to download a high resolution image of any frame, and to share custom frames with other users (so if we get additional reference material or need to make corrections it’s just a matter of updating code instead of editing graphics).

Edit: First pass at recreating “WE’RE BACK”, using the above reference photo:

[ZeroSum]

Nice!

[mrmichaelt]

Ghostbusters fans are cool people.

Great sleuthing and work!

[prodestrian]

I’ve updated my posts above to include the new reference images and correct text.

So the next thing is to be able to uniquely identify every separate frame in the sequence.

Although “GHOSTBUSTERS” and “CALL JL5-2020” are repeated every loop, I want to give each instance a different identifier so we can keep track easier.

Here’s my spreadsheet so far:

NOTES

1. Frames A + F have the same text, as do frames E + L
2. I thought about the “shimmer” being represented as its own frame, but it seems like it’s actually just part of frame F (GHOSTBUSTERS)

Movie Analysis

During the first nighttime shot of the ECTO sign in the film (00:37:06, right after “certified check, cash, or money order!”), we see frame A (GHOSTBUSTERS), then frame B (FOR HIRE). We know it’s frame A and not F because we see it transition to frame B.

There’s a cut and we see frame G (WE’RE BACK).

Later in the montage (00:38:10, daytime) we see frame C (WE’RE READY) on one side as it turns the corner, then frame D (TO BELIEVE YOU) on the other side.

As the ECTO arrives at the museum (00:49:44) we can just make out that it says “CALL JL5-2020” (either frame E or L), then transitions to “GHOSTBUSTERS” in red (either frame A or E). The transition is fast, the first frame slides down and the second frame slides up. We never see either frame flashing or animating. This isn’t enough to determine which frames they are in the sequence (YET).

Later as the ECTO speeds to the museum at night (01:22:59) the sign says “GHOSTBUSTERS” in green, which rapidly flashes back and forth to red. We then see it start to transition to frame B (FOR HIRE…). This means frame A (GHOSTBUSTERS) must be the red/green flashing text. As it drives through the crowd (01:23:10) it still says “FOR HIRE…” (frame B). In the wide shot, we see it transition to frame C (WE’RE READY).

As it turns the corner (01:23:17) it shows frame K (US!) and then transitions to frame L (CALL JL5-2020). This slides down, then back up again into red GHOSTBUSTERS text, so we can be confident that this has looped back to frame A. Which confirms that the daytime museum arrival (00:49:44) was actually frame L followed by frame A after all.

When Venkman gets out of the passenger seat and closes the door (01:23:28) it says “CALL JL5-2020”, then we have a red wipe to “GHOSTBUSTERS” in green, which then starts to shimmer. So this seems to be frame E, then frame F.

The next shot (01:23:36, “I hate jello”) is mostly obscured so I can’t be confident of what’s being shown here.

As the four Ghostbusters approach the slime (01:24:46) it shows frame D (TO BELIEVE YOU) and then wipes down to frame E (CALL JL5-2020). We then start to see it transition with a red wipe to frame F (GHOSTBUSTERS) but only for a fraction of a second. At 01:24:54 (“pull 'em”) it shows frame J (CALL?) followed by frame K (US!). I don’t think there’s any more footage in the film, except obscured/blurry shots.

Getty Video Analysis

This 42 second video is made up of two separate shots (14 seconds + 28 seconds) stitched together.

We start with frame F (GHOSTBUSTERS) wiping from green to red, then a solid red transition to frame G (WE’RE BACK).

Interestingly it doesn’t show “WE’RE BACK”, it shows “WE’RE” in red, followed by a solid flash of green, then “WE’RE BACK” before it starts flipping each word back and forth between red and green.

We then get 5 vertical lines spread across the sign, each one wipes across before being replaced by a green box. This loops multiple times before we get frame H (WHO YA), then frame I (GONNA), then frame J (CALL?).

This frame slides upwards, before **frame K (US!) **appears. The video cuts when the green arrows start to blink.

In the second shot we’re looking from the front of the car so it’s hard to see the sign, except that it’s blurry green transitioning to blurry red (definitely frame A (GHOSTBUSTERS)). The text seems to slide up and down multiple times while swapping colors, possibly even flipping upside down (as per that GIF from the deleted scene in my post above).

We then clearly see the shimmer animation for a few seconds, before it shows “GHOSTBUSTERS” again in green. This rapidly swaps back and forth from green to red about 16 times before showing a solid green frame, which wipes to frame B (FOR HIRE…). We see a solid green wipe, then frame C (WE’RE READY), frame D (TO BELIEVE YOU), and then finally frame E (CALL JL5-2020) slides in from the top. It transitions out with a red wipe into frame F (GHOSTBUSTERS). Then the video ends.

With all of this information I’ve been able to make a lot of progress on my spreadsheet, I’ve only got a few empty cells to fill in. But I need to do another pass over everything because some of these were early assumptions that I think may be incorrect now:

Sidenote: It’s nice to finally understand what the heck is going on in this promo photo! (It’s mid-way through the frame A animation :lol:)

[edspengler]

This has been a great read!

[d_osborn]

What a cool thread!

I don’t have much to add, but there might be a few extra clips in the full EPK. I could be wrong, but I think what’s posted was edited. Around 37:25.

https://www.youtube.com/watch?v=-Vte68NZUDY

[d_osborn]

This one kills me. It’s wide open on the end! How have I never noticed that? It looks like the fronts were sealed up, but they were driving around in the NYC snow, ffs! It’s wild they consistently worked. I really wish we had some sort of documentation on who built these things for Chuck Gaspar. The Ghostbusting Man of Mystery.

More kudos on this research. New Haslab panels would be cool, but small working desktop models would be cooler. Same aspect ratio, resolution, just scaled down.

Now to throw a huge wrench in things, WTF is this logo? CRAY, manufacturer of the Cray Supercomputer, was my first thought. I’m not seeing anything that looks close, though.

EDIT- Screen grab from the BTS home movie with the two kids at the museum.

[prodestrian]

@d_osborn post_id=5008298 time=1770151166 user_id=21

This one kills me. It’s wide open on the end! How have I never noticed that? It looks like the fronts were sealed up, but they were driving around in the NYC snow, ffs! It’s wild they consistently worked. I really wish we had some sort of documentation on who built these things for Chuck Gaspar. The Ghostbusting Man of Mystery.

My assumption was that the LED matrix is fully enclosed but oddly shaped, so they built a larger enclosure for it. It might also be so it could be more easily swapped out if it breaks down or needs to be reprogrammed for specific scenes.

It was probably some kind of commercial sign product designed to be used outdoors anyway. Hard to know for sure.

But in some scenes (mostly at the firehouse) you can see a clear protective cover over it. They may have had to abandon this because it was too reflective, especially during nighttime scenes.

@d_osborn post_id=5008298 time=1770151166 user_id=21

More kudos on this research. New Haslab panels would be cool, but small working desktop models would be cooler. Same aspect ratio, resolution, just scaled down.

Definitely possible, it’s just a matter of translating the pixels. I’d love to release some code to do that eventually, so you could type in your pixel width/height and have it convert for you.

@d_osborn post_id=5008298 time=1770151166 user_id=21

Now to throw a huge wrench in things, WTF is this logo? CRAY, manufacturer of the Cray Supercomputer, was my first thought. I’m not seeing anything that looks close, though.

EDIT- Screen grab from the BTS home movie with the two kids at the museum.

Those are great! I tried going down this rabbit hole a few weeks ago without any success. I had seen the video with the two kids but the logo was too blurry, I think you’ve captured the clearest shot (but it doesn’t help much). The only other one I could find was here, when Peter gets out of the car at the museum:

It doesn’t show text but it does slightly reveal the shape.

The second photo you posted is much more helpful, I’ve never seen that before!

If the label did say “CRAY”, it would be because they glued it on (similar to the Burroughs labels etc) rather than it having anything to do with the sign itself. Personally I think it’s more likely that it’s the name of the the sign’s manufacturer, or at least where they bought it from. I can’t see that label in any photos from Universal Studios so it was probably lost by then. The footage from the 1989 premiere is too blurry and far away to see anything too.

In your photo the letters look like they’re styled like a dot matrix. The “C” might even just be 3 white squares. If that’s true (which is a big if), it would allow us to guess the rest of the text. But I tried multiple combinations of letters and none quite lined up, so maybe this is a red herring. I really wish we had just a few more pixels to go on. I’ve tried searching for various combinations of keywords without any luck (“CMX digital signage California 1988 dot matrix display”, “CMY digital marquee 1980s”, for example). I’ve tried looking for more behind the scenes photos which might show the label close up, again no luck. The label does appear on both signs in the same place (bottom right) so at least we know where to look.

[ZeroSum]

I went down a bit of a ChatGPT rabbit hole trying to find out if the sticker is the logo of an led sign manufacturer.

TL:DR, I couldn’t find a matching logo.

What I did find - ChatGPT is certain the sign board used was a Adaptive Micro Systems Alpha 216C or Adaptive Micro Systems Alpha 215C. Sepcifically, the 80 pixel wide measurement corresponds to the Adaptive Micro Systems Alpha 216C LED Message Center (dual-color). Manufactured approx 1986–1989.

The bad news is that neither myself nor ChatGPT is able to find anything about that sign board on the internet. No photos, manuals or anything. The company still makes a modern version of the 215C, but that is not very useful.

There is a modern manual (2006) - Alpha Message Sign Communications Protocol https://alpha-american.com/alpha-manuals/M-Protocol.pdf which in appendix O lists character sets for several pixel heights and shows pixel layouts. I haven’t checked to see if any of these correspond to what is seen in Ghostbusters screenshots. Maybe there is useful stuff in that manual.

So I have to assume that sticker is not the led sign manufacturer. It’s very hard to make out what it says.

[prodestrian]

@ZeroSum post_id=5008313 time=1770353482 user_id=53413

I went down a bit of a ChatGPT rabbit hole trying to find out if the sticker is the logo of an led sign manufacturer.

TL:DR, I couldn’t find a matching logo.

What I did find - ChatGPT is certain the sign board used was a Adaptive Micro Systems Alpha 216C or Adaptive Micro Systems Alpha 215C. Sepcifically, the 80 pixel wide measurement corresponds to the Adaptive Micro Systems Alpha 216C LED Message Center (dual-color). Manufactured approx 1986–1989.

The bad news is that neither myself nor ChatGPT is able to find anything about that sign board on the internet. No photos, manuals or anything. The company still makes a modern version of the 215C, but that is not very useful.

I wouldn’t trust ChatGPT with anything. It’s not a search engine, it’s an LLM trained using old datasets. It predicts the next words to give you the answer to the context input you submitted (the question you asked) regardless if that answer is correct. It’s going to hallucinate and waste everyone’s time here.

When I visited the Alpha American site 3 weeks ago I couldn’t see anything useful there in their current product lineup:

The 215 series is 90 pixels wide, not 80. It’s also only 70cm wide, far too small for the Ecto.

It’s true, the Adaptive Micro Systems company has existed since the 80s, so it’s plausible they could have manufactured the Ecto sign. But even going through their old website from 2000 via the Internet Archive didn’t reveal any products there which looked relevant. The archive even has captures of their technical manuals going back to 1998 but without knowing which product to look it’s going to be difficult. So far none of them seem to have the clustered LED patterns that the Ecto sign has, they’re all single pixel LEDs.

The Alpha 330 series is is closer in physical dimensions to what we’re looking for, but it’s 180 pixels across (because it doesn’t have the pixel clusters we’re looking for).

There might be more to look at there but it’s going to take time to go through the archive, and that’s if they bothered to publish any of their products from the 1980s on their website from 1998 onwards.

The larger point I’m making here is that just because ChatGPT says it’s definitely made by this manufacturer doesn’t mean it’s true. It could be one of their competitors, maybe someone that has since gone bust. ChatGPT isn’t going to help here, this is going to take actual human research to find (just like when I found the blue bumper label, I doubt any AI had even heard of “Terminal Data Corporation” at that point).

Sidenote: As a software engineer I’ve worked with AI, LLMs and Machine Learning for nearly 10 years. I know exactly what this technology can and can’t do, which is why I don’t use it for searches like this.

I once asked ChatGPT which films Ricardo Montalban had starred in (while looking for an answer to this thread), and it told me with absolute certainty that it was a film called “Ghengis Khan (1975)”. 10 seconds on IMDB was enough to confirm that no such film exists, it’s just another case of an LLM hallucination :lol:

Edit: If you could get your hands on an “Alpha Big Dot” sign, those are 80x7 pixels and tricolor (red/green/yellow). They’re far too small but would make a great sign for a smaller car or a wall display. Tempted to setup an eBay alert for one… :lol:

Edit: Nice size comparison of the various Alpha models from the 1998 website:

And the specs showing the dimensions and the pixel counts: