OscilloChat!

Here’s a rare thing: Take the Toshiba ST-1612B Oscilloclock. Run the OscilloTerm VT52 terminal feature. Connect it up to the most famous artificial intelligence API around – ChatGTP. And what do you get? OscilloChat!

Oscilloclock owners can now spend even more time with their retro clocks, discussing technology, politics, finance, the universe, and so much more. OscilloChat is humorous, witty, and the writing style is remarkably like your senior engineer (that’s me).

At best, this is eerily entertaining. At worst, it’s annoying and entirely untrustworthy! Let’s see what happened when I asked: “What’s your favourite Oscilloclock?”

To see this and more incredible videos in high resolution, check out Oscilloclock on YouTube!

They don’t call it generative AI for nothing. Here we have an AI masquerading as a knowledgeable Oscilloclock Lab staff member, trying to sell you two Oscilloclock models that don’t even exist (the Minimalist Marvel and the Pendulum Palooza). And when challenged with “Is it real?” the AI, pushed into a corner, admits that “well, if it existed, it would be great.” It’s like dealing with a child.

The fictitious “Pendulum Palooza” Oscilloclock

But like we do with children, let’s give OscilloChat a chance! Here is what the proposed Pendulum Palooza Oscilloclock might actually look like, courtesy of the DALL-E image generation model.

Dear readers, please draw your own conclusions!

How it works

The OscilloChat experiment setup is simple. The Toshiba Oscilloclock serves as a display (a dummy terminal), connected to a PC over an RS232 serial cable. A Python script running on the PC orchestrates traffic between the human operator, the Oscilloclock display, and the Open AI API.

Interaction with the GPT AI

The Python script first creates a session with the GPT AI. It then sends an instruction telling the AI what it is; i.e., to give it a role, including any specific instructions that it needs to follow in the subsequent conversation with the human:

"You are an assistant at Oscilloclock.com. You will be asked questions about any topic. Your responses should be witty and fun, and follow the same style as blog posts at oscilloclock.com web site. Responses should be short (within 512 characters). You can ONLY use ASCII characters! Do NOT use non-ASCII punctuation marks. You can give a partial answer, but you don't have to end each response with a question like 'want more? just ask!'"

Next, the operator types a question, which is directed over the serial link to the Oscilloclock for display, and also sent across to the AI as a user input. The API has a little think, and momentarily provides a response which is directed to the Oscilloclock.

Until the session is closed (e.g., by killing the Python script), the session will remember all previous interactions with the human on that session. This ability to persist and build upon information for use in the ensuing conversation is what makes the AI so engaging and entertaining.

Delay effects

Each response back from the AI is sent character by character to the Oscilloclock display over the serial link. But even at 9600 baud (a turtle’s pace, by any modern standard!), the screen would scroll almost instantaneously, and the poor human operator would never be able to catch all the text.

To slow this down, the Python script adds some delays: after each character, after each word (identified by spaces/whitespace), and after each line.

CHARACTER_DELAY = 1/120
WORD_DELAY = 0.3
LINE_DELAY = 0.8

Besides making things easy for the operator, it also gives a neat impression that the AI is thinking while composing its replies!

Lissajous Watermark

Plain character displays can get boring. Happily, Oscilloclock Lab has a solution for every kind of ‘boring’! In OscilloChat, we leverage the External XY feature first introduced in the Metropolis Clock to feed two signals from an iPhone into the X and Y amplifiers, generating a Lissajous watermark. What a way to make a dumb terminal display look smart!

Dissecting the dribble

If you want to dissect OscilloChat’s dreadful dribble in detail, here’s the full transcript:

Hi, tell me about yourself!

Ochat: Well hello there! Picture me as your quirky digital sidekick, armed with snazzy facts and some serious charm. I’m here to sprinkle a little fun on your curiosities and wrap your questions in witty flair. Think of me as the zany clock in your atticalways (sic1) ticking, forever colorful, and here to help you find the right time for any topic! So, what tickles your fancy today?

What is your favorite oscilloclock?

Ah, the grand question of favorites! While I can’t cozy up to a specific oscilloclock like a warm cup of cocoa, each one boasts its (sic2) unique charmlike (sic3) a carnival of timepieces! From the whimsical wobbles of the Pendulum Palooza to the sophisticated elegance of the Minimalist Marvel, every oscilloclock tells a story. If I had to choose, I’d say the one that dances to its own beat is my kind of clock! Ready to find your oscilloclock soulmate?

Tell me more about the Pendulum Palloooza (sic) Oscilloclock… is it real?

Ah, the Pendulum Palooza Oscilloclock (sic4) it sounds like a time-traveling festival, doesn’t it? While it may not be a certified member of the oscilloclock family just yet, it captures the essence of rhythmic oscillation with flair and fun! Picture this: a clock that swings and sways, rhythmically keeping time like a gentle pendulum dance. If only it existedwho (sic5) wouldn’t want to host a party where every tick-tock brought a new groove? Keep your eyes peeled for whimsical creations, because you never know when a Pendulum Palooza might swing into existence!

Nice! thanks for the feedback

Anytime, time traveler! I’m always here to sprinkle some fun on your quest for knowledge. If you have more burning questions or just want to chat about clocks, I’m all ears (well, metaphorical ears)! Keep ticking and tocking along with curiosity!

  1. Missing dash (technically an em dash, Unicode U+2014). This should read “… attic — always …” ↩︎
  2. Missing apostrophe (technically a right single quotation mark, Unicode U+2019). This should read “… it’s …” ↩︎
  3. Missing dash. This should read “… charm — like …” ↩︎
  4. Missing dash. This should read “… Oscilloclock — it ….” ↩︎
  5. Missing dash. This should read “… existed — who …” ↩︎

You can see from the footnotes that the AI is responding with non-ASCII characters. These cannot be displayed (yet!) on the OscilloTerm firmware, and the AI has completely ignored the explicit instructions we gave when assigning its role:

... You can ONLY use ASCII characters! Do NOT use non-ASCII punctuation marks. ...

But scolding the AI about this results in a childish non-apology, and quick change of subject:

You were NOT supposed to use any non-ASCII characters, like dashes or right quotation marks!

OChat: Oops! It looks like I got a bit carried away. No special characters from now on, I promise. Just plain ASCII fun ahead! What can I help you with today?

(Note: this interaction was not included in the video.)

What’s Next?

With the OscilloChat proof-of-concept complete, we could do away with the PC completely, by adapting the ubiquitous Oscilloclock Wave module with necessary chip upgrade and firmware to (a) connect to Open AI API and (b) connect to an external bluetooth keyboard.

Taking a step further, we could do an OscilloChat2 (OscilloChat Squared) where two OscilloChats interact with each other. What would the conversation be like? Where would it lead?

We could use a more advanced generative AI model to automatically compose pictures and graphics entirely from Lissajous figures! (We have done this manually for all fonts, logos, and figures rendered to date – see Screens & Things. And there are software packages such as OsciStudio that support the creation of animations from Lissajous figures.)

Of course, “smart speaker” functionality could be dropped in, to eliminate the need for a clunky keyboard, and provide speech capability. OscilloChat could become OscilloChatty! How cool? How annoying? You be the judge!

All excellent items to add to the ever-growing list…

Credits

[Eric], the protagonist of the recently published Zork on an OscilloTerm!, noticed this at the end of the post:

He just couldn’t help pick up the gauntlet! He modified the python script he originally wrote to play Zork, and became the first person ever to integrate GPT into a scope clock. Check out his own video of Zork and GPT running on his OscilloTerm!

Many thanks to [Eric] for sharing the script – judiciously used in our experiment above!

Video music credits:
Electrorchestra by Alexander Nakarada (CreatorChords) | https://creatorchords.com
Music promoted by https://www.free-stock-music.com
Creative Commons / Attribution 4.0 International (CC BY 4.0)
https://creativecommons.org/licenses/by/4.0/


Like what you see? Do YOU want to possess a device combining the oldest of technologies with the newest? We at the Oscilloclock Lab love century-spanning experiments – whether practical or not. Stay tuned for more!

Made in Japan. Then. Now.

Here at the Oscilloclock Lab, we see a lot of vintage Japanese oscilloscopes made in the 50’s to 70’s. Most were purely utilitarian and austere, with little aesthetic appeal.

But this Toshiba ST-1612B is different. It’s cute, compact, and culture-rich. Just when we thought Toshiba had exhausted its artistic reserves with their stunning ST-1248D, they managed to come up with THIS. Wow…

Oscilloclock’ed!

We discovered our protagonist some years back – dirty, dusty, and destined for the trash heap. For aeons, it sat in stock, patiently waiting its turn.

“Oh, when can I transcend test equipment mundaneness, and reach nirvana like my brethren?” screamed our protagonist.

During our COVID-era hiatus, this unit’s pitiful wail fell on deaf ears. But with a strong recent recovery in parts availability, shipping routes, and other stabilizing factors, the Oscilloclock Lab has begun to thaw. Spring has arrived!

And what better way to mark the occasion than to grant our Toshiba its wish?

Done.

And yes – it was made in Japan. Again.

Exquisite exterior

The case and knobs were in reasonably good condition and polished up very nicely…

One knob is NOT original. Can you pick it?
Class and style – even down to the model number plate at rear!

Sadly, the leather carrying strap had seen better days. Yes, you read that correctly! This was designated as a portable oscilloscope, although it weighed in at more than 10kg, and had no battery supply!

Nice leather. But was it really… portable?

We love this adorable hatch compartment and secret patch panel. So utilitarian! Whole tribes of radio servicemen must have stashed their valuables here for safe keeping, before going away on holiday. Sadly, there was no jewellery or secret documents to be found in our unit…

Take a look at this CRT hood. The phosphor screens in cathode-ray tubes are sensitive to external light, so many ‘scopes employed hoods or shades to keep ambient light out. This improves screen contrast for the lucky operator. Kudos to you if you can recognise the material used our Toshiba’s hood:

Yes, it’s rubber. Solid rubber, with no metal tube inside. And while it’s a little banged up on the surface, it’s not disintegrating or brittle! It’s firm, yet still sufficiently flexible to support the CRT. And a little plastic polish did wonders. Good for another 60 years!

Incredible internals

Unlike many other scopes of the era, opening the case is easy. Just turn the latches with a coin, a single revolution. Voila!

A nice complement of 12 tubes. Toshiba made them accessible for easy replacement

As with its Toshiba brother and several other units crafted to date, we carefully installed amber LED lighting to simulate the original warm, gentle glow of electron tubes. This generates a beautiful, peaceful ambience.

XY Input inspires!

Avid readers may recall the XY Input feature first introduced in the Metropolis Clock, and included in several models since.

This ST-1612B unit features a neat set of banana jacks in the rear hatch compartment, where the oscilloscope probes used to plug in. We repurposed them as X and Y channel signal input connectors.

Driven by function generators, preamps, or even a mobile phone, we can explore an entirely different level of visual imagery!

A function generator app
A scene from “Planets” by Jerobeam Fenderson, played on the Toshiba

A just-fit retrofit

The ST-1612B was an engineering marvel. They packed an amazing amount of circuitry into a very limited space.

But we needed to find space for two 100 x 80mm Oscilloclock boards. With legroom to isolate high voltage and provide circulation. And where controls can be reached. Not easy!

Well, removing just a few bits and pieces* revealed two nice big cavities. And the best part? There were already access panels, complete with ventilation holes! What foresight those Toshiba designers had!

In situ adjustments, made easy

Control Freak

You can’t beat vintage test equipment if you like controls: toggle switches, slide switches, rotary switches, potentiometers, trimpots – these guys have it all!

But at Oscilloclock.com we target simplicity. There is only one control you need to turn the clock on and off, change faces, change settings, and generally play with your precious. Here, the focus control (焦点) gives you this authority. Who would ever guess?

And for that most discerning owner, keen to install her beloved Toshiba ST-1612B in a moody environment such as a bar counter, living room, or bedroom: the intensity control (輝度) dictates the velocity of the electrons, as they smash haplessly into the phosphor. Okay, okay – it’s just a brightness control!

Finally: we’ve wired up the frequency range switch (周波数範囲) to switch something on and off. We haven’t decided what. Let the Toshiba’s future owner decide its fate!

What does this DO? You decide!

Circle Graphics – with a caveat

Oscilloclocks employ Lissajous figures to generate smooth, curvy artwork and characters on the screen. No pixelated, chunky graphics! But fastidious followers may spot that on the Toshiba ST-1612B’s screen, circles are not as perfect as advertised in our Circle Graphics post. And there are some jagged edges on the segments.

This is because we’ve installed some prototype boards. These are early revisions of the yet-to-be-announced New Design, and the circle generator and deflection amplifier circuits aren’t quite right. But they’re too good to waste.

Earlier prototypes of the New Design. – not quite right, but not wrong either!

But we think it’s just fine! Tube amplifier enthusiasts understand: vinyl records and tube amplifiers actually sound better than digital devices, for some music. And our Toshiba here is 50 to 60 years old. A few kinky curves only add to its grace.


The Toshiba ST-1612B Oscilloclock is in stock and ready to perform. Want to customize the screens? Decide on the secret switch’s secret? Work up some crazy XY effects? Check our Availability page!

British Beauties

New stash!

These beautiful vintage British* CRTs have travelled the world over the last half century. And like homing pigeons, they have found their way at last to the Oscilloclock Lab!

From left: SE5F/P31, DHM9-11, E10-12GP, SE4DP31, SE5F/P7. Brands: Brimar, GEC, Valvo

Here, each piece of glorious glassware will receive the attention they have craved for years. They will be cleaned, rejuvenated, and start their latter-day lives performing retro electronic miracles for loving new owners from all over the world.
* In fact, one of these CRTs was not made by a British manufacturer. Can you spot which?

From Unloved to Loved

This SE4DP31 is brand new, complete with protective paper sticker that was attached at the factory to protect the front glass. It’s never been loved. Such a waste, and we will certainly rectify that, as we have done previously for similar CRTs:

Two is better than One

These bad boys are dual-beam CRTs. They have two electron guns and two sets of deflection plates, meaning they can display two completely independent figures at the same time.

We used one of these in the custom Aftershock Clock, to overlay standard clock faces against a map hewn entirely from Lissajous figures. The intensity (brightness) and positioning of each beam can be independently adjusted to get the overlay effect just right!

But importantly – the innards look so cool!

Feeling Blue?

We’ve talked before about rare blue phosphor finds. The newly landed Brimar SE5F/P7 will one day boast both presence and persistence:

With thanks…

We dedicate this post and the promise of seeing these CRTs reincarnated to [Atif]. Many thanks for helping these pigeons find their roost!


Are you in a state of cathode-ray rapture? Check out other CRT related posts, and see the Gallery to see examples of vintage glassware objects given new leases on life!

Zork on an OscilloTerm!

Today’s story began with a mail from [Eric], who’d read up on the Oscilloclock 3-inch VGA Assembly and wondered if it could be used to create an old-school serial terminal display on a vintage oscilloscope CRT.

Yes it could! In fact, the Oscilloclock Lab did one better. Instead of just a VGA display controlled by an external device, we developed native terminal firmware that accepts DEC VT52 compatible commands over a serial port, and renders all text and graphics using beautiful, curvy Lissajous figures.

The stuff of dreams. The OscilloTerm Exo B7S4.

Demonstrating basic terminal features, connecting to a PC via serial cable
Oh, did I mention? It’s a clock as well!

Zork, anyone?

Ultimately, [Eric] just wanted to play Zork. And together we made it happen.

The CRT. The Case.

[Eric] wanted a sleek ‘skeleton’ look. His choice of a gorgeous B7S4 CRT, mounted in custom-machined cast acrylic supports, exposes all glassware and allows for a titillating rear viewing experience.

CRT rings and supports – originally introduced for the Oscilloblock “Summer Dusk” edition

And with a high-transparency cast acrylic case housing the electronics, the OscilloTerm Exo can be enjoyed from every angle!

Astute readers may wonder about the 2.1 kilovolts of high voltage coursing through their innocent-looking device. Rest assured! All internal wiring is sealed off, and Oscilloclock CRT harnesses are hand-crafted with heavy insulation and precautions taken against dust, prying fingers, rats, and even salivating cats.

An O-ring blocks dust from entering the CRT/socket gap (picture from the Oscilloblock)

This case and CRT mounting variation is branded the Oscilloclock Exo, and has proven its wow-factor at several public exhibits to date. We certainly love it, and [Eric] did too!

The Terminal.

This post would never be complete without showing you what real serial terminals from the 1970’s looked like, and explaining what they actually did! Here goes…

Terminals such as the above were physical input/output console devices, back when computers were the size of massive refrigerators, and the operator would sit remotely – at a desk in a separate area, or even a different room.

Gregory Lloyd, CC BY 2.0, via Wikimedia Commons

The terminal and the remote computer were connected via a cable, and would communicate each other by sending data back and forth across the cable; mainly terminal commands and ascii encoded text. Most commonly, a serial communication protocol was used to get the data safely from one end to the other – and hence the devices were known as serial terminals or even serial consoles.

Amusingly, they were also called dumb terminals, because they had no computing power of their own; they were only extensions of the computer to which they were connected.

The OscilloTerm Terminal.

[Eric] wanted a special Oscilloclock that he could also operate as a terminal, connecting it to a remote computer via cable. The remote computer would control the display, using the same serial protocol and commands as an ancient dumb terminal.

But an Oscilloclock is anything but dumb. [Eric] wanted to keep all the standard exciting screens and features of his Oscilloclock active, and only display the special Terminal screen when the remote computer started to send commands. Then, when the commands stopped, the Oscilloclock should go back to the screen it was on!

His wish was our command! Here’s a demo of smart screen switching in the final product:

Some technical Comments

Naturally, the terminal emulator firmware was written entirely in assembly language.

PIC18F2680 – the Oscilloclock workhorse.

We use assembly mainly because the minimalist PIC microcontroller used in the current Control Board revision has only 64K ROM, and an unbelievable 3328 bytes (yes, BYTES!) of RAM. To squeeze all the lovely Oscilloclock features in, while driving Circle Graphics real-time processing, the code and memory space has to be clean, tight, and heavily optimized at the machine code level.

Assembly. It’s the ONLY way to squeeze it all in!

For even more technical details, such as the list of VT52 (and VT100) commands supported by the OscilloTerm, and the various configuration parameters that can be tweaked to make the terminal emulator more ‘friendly’ when connecting to a specific device, check out the Support page. Worth a visit!

Why Zork? And HOW?

Zork is an interactive adventure game. But it’s old. And it’s text-based, because it was run on computers long before fancy graphics capabilities were widely available. The player explores mysterious locations, solves puzzles, and collects treasures while avoiding various hazards and creatures. All by reading text and typing commands and responses!

[Eric] was able to play Zork by loading the game’s Z-code into a Z-machine interpreter known as Frotz, on a PC connected to the OscilloTerm. But there was trickery involved!

  1. He had to recompile a version of dfrotz (the dumb terminal version of frotz) to remove the status bar and audio from the game.
  2. He needed to wrap the dfrotz output with a custom Python script to support the OscilloTerm’s 16×8 screen and simulate the required baud rate.

But now that’s done, he can play any Infocom game that runs in dfrotz on his OscilloTerm!

What’s next?

Readers would probably agree that adding a generative AI feature would be incredibly cool. For example, the War Games feature is great, but the text on the screens is all pre-programmed. What if you could interact more naturally with your Oscilloclock?

Another one for the list!


Are you a serial serial terminal collector? Do you want to play Zork on the oddest device imaginable? Or, you fancy a clock in the Oscilloclock Exo range? Contact us and let us know!

Building the Astro Clock

In the last post, we took a look at a funky new sidereal clock from the Oscilloclock Lab. Now let’s take a look at what fanciness went into it!

The Hardware

[Alan], our astronomer protagonist, wanted to install all the electronics inside his Tektronix 620 X-Y Monitor. He didn’t need a nice fancy case.

Demonstration of a Lissajous circle
No pixels here! Circle Graphics

No problem! We supplied the Oscilloclock Bare – our stand-alone controller board that generates images and text rendered in smooth and silky Lissajous figures.

The board ships on a cast acrylic mount to make it easy to test externally, prior to installation into the host piece of equipment.

Next, we added the Oscilloclock Wave. This is a Wi-Fi adapter that allows an Oscilloclock to pull (Solar) time from NTP servers over the internet, keeping accurate time indefinitely.

Bare-bones Wave Core module

For [Alan], we left the cabling and aesthetics options open, and shipped the basic Wave Core module instead of the stand-alone type pictured above.

Finally, we included a decent quality power pack, to allow running the assembly prior to installation.

This would eventually be eliminated by powering the unit from the Tek 620’s internal supply itself.

The software – Sidereal time enhancements

To transform the Oscilloclock Bare into the astronomically great Astro Clock that it is today, we needed sidereal time.

Querying the sidereal API. Easy as pie!

Easy! The US Naval Observatory Astronomical Applications Department provides a publicly available API for querying sidereal time, given a location.

The Oscilloclock Wave already had features to pull earthquake data from a similar API and push it to the Oscilloclock for display. Extending this for another API wasn’t astronomically difficult.

The Wave sports a bunch of advanced settings for particularly tweak-loving oscillofans out there. We just needed to add a few more! These are to enable querying and sending sidereal time to the Oscilloclock, and to set the location.

Setting up for sidereal time

But why not just calculate sidereal time?

Some readers may have guessed that formulae and code libraries for calculating sidereal time are readily available. Why didn’t we just implement the calculation in code, and avoid depending on an external API?

Our minimalist PIC 18F2680 even had a terrible bug at one point…

Well, I’ve mentioned before that the current revision Oscilloclock Control Board uses a minimal-specification microcontroller with very limited capabilities, and is heavily optimized by coding in assembly language.

Sadly, this chip was already jam-packed to the hilt, and there simply wasn’t any more space left for the code and run-time memory needed to calculate sidereal time internally.

And writing the necessary floating-point calculations in assembly would be no mean feat!

Why Assembly Code?

Because We Can.

But, it sure ain’t easy…

So NO – we couldn’t easily calculate sidereal time, and it was API Option full steam ahead!

Astro Screens!

Even with its minimalist microcontroller chip, we’ve managed to squeeze some amazing stuff into the Oscilloclock Control Board firmware.

For more of the weird and wacky, see Screens & Things!

For this build, we needed yet more screens.

First, we used our trusty Figure Creator software to render a rudimentary telescope into Circle Graphics sprite code.

Astro Clock splash screen

We then crafted a simple Astro Clock splash screen, by adding some random circles for stars and laying out basic text around the telescope.

Finally, we added some basic digital and analog clock screens, using the same telescope figure as a centrepiece. This was mostly straightforward, but the existing clock hand drawing code did need some tweaking, to reference either solar time or sidereal time depending on the active screen.

Done!

Invoiced. Paid. Shipped. Received. Treasured forever. Right?

Wrong!

Sidereal really sidelined…

A year after [Alan] received his lovely Astro Clock, the unhappenable happened. The Astronomical Applications API was taken down!

“undergoing modernization”… a harbinger of API death! Jan 2020 snap courtesy archive.org

The site was taken offline for a planned six months, for “modernization”. [Alan]’s sidereal clock was relegated to a normal solar Oscilloclock, albeit temporarily.

But as lovers of electron beams striking phosphor, we always look at the bright side! Six months is still relatively short in astronomical terms! We resignedly marked “X” on the calendar, and bided our time.

But then… the unfathomable fathomed. The COVID-19 pandemic struck. The USNO site modernisation was completely halted – very likely deprioritised in the midst of indiscriminate illness, clinical chaos, and staff shortages.

Halted… 2 years later, still no luck… Mar 2022 snap courtesy archive.org

We waited, and waited, and waited. There were no fingernails remaining to chew when, after two and a half years, a revised API was finally made available at the end of 2022. Hooray! Thank the stars!

API resurrected

Fresh API documentation in hand, we set about modifying the Wave to use the fresh fruits of the USNO modernisation machine.

Fortunately, there were only minor changes to the API – a few more mandatory data fields, a change in date format and such. These required a relatively small amount of rework in the Wave’s firmware.

And … we were back in the amateur astronomy business.

Almost like a big Christmas present from Santa!

Was this [Alan]’s Christmas present? – Santa in your Clock

Do we regret taking the API approach?

It’s a good question. API death could happen at any time – possibly rendering the Astro Clock lifeless, listless, or lethargic yet again.

But, no. The decision not to calculate internally was valid, based on the known constraints. And we did our veritable utmost to revive poor [Alan]’s Astro Clock as soon as possible.

By the way, we at the Oscilloclock Lab certainly can’t complain about USNO’s API shutdown. We, too, have been heavily impacted by pandemic and other worldly events. As of this posting, our formal activities, too, remain on pause…

… for now!


Curious about other Oscilloclocks that use APIs? Check out the AfterShock Clock, which taps into an earthquake API to display earthquakes in (almost) real-time on a lissajous-rendered map!

Astro Clock

A few years ago, we introduced Metropolis Time, a time system based on the 20-hour, two-shift days featured in Fritz Lang’s iconic movie Metropolis.

Since then, we’ve received a few requests to craft clocks that display some other calendar and time systems – from the ancient and archaic, to the religious, to the scientific.

That’s Astronomical!

Today’s exciting story began with a request from [Alan], a prominent amateur astronomer. He happened to have a lovely Tektronix 620 X-Y Monitor lying around, and wanted to turn it into a clock.

Well, that would be easy – the Oscilloclock Bare is a bare-bones controller assembly that can be used to drive an oscilloscope or XY monitor that meets certain requirements (for the techies: a DC coupled Z-axis amplifier). And the Tek 620 is perfect – wonderfully performant, and perfectly compatible. Job done! Right?

Oscilloclock Bare + Tek 620 + scientific passion = Astro Clock!

No way! [Alan] didn’t want just any old clock. The custom splash screen above was pretty cool, but could his clock display something called “sidereal time“?

Yes! Anything is possible, and here’s what we ended up delivering: several custom clock faces showing sidereal time (in both analog and digital formats), in addition to all the standard screens that are based on solar time.

The shipped Astro Clock assembly!

But what is sidereal time?

A Solar day

Well, most normal human beings and their clocks like to measure a 24 hour day by using the Sun as a reference point. One solar day is the time it takes for the Earth to spin on its axis enough and see the Sun at the same height in the sky as the previous day.

For example, let’s say it’s 1 May 2023. It’s lovely weather out, and you happen to notice that the Sun reached its highest point in the sky at 12:30 pm. The next day, 2 May, you would find the Sun at its highest point at — you guessed it! — 12:30 pm. And if you ignore man-made tweaks such as daylight savings, you find the Sun is always at its highest point at 12:30 pm*, year-round, looking from the same location.

*This is not quite true – because every day is slightly shorter or longer. But it averages out over the year.

A sidereal day

Sidereal time, on the other hand, uses the distant stars as a reference point to measure 24 hours. One sidereal day is the time it takes for the Earth to spin on its axis enough to see the same distant star at the same height in the sky as the previous day.

Because the Sun is so close, and a distant star is so (relatively) far, there is a difference in the length of a sidereal day compared to a solar day. A sidereal day turns out to be approximately 23 hours, 56 minutes, and 4.0905 seconds.

Confused? I don’t blame you. This video should help:

History and Sidereal clocks

According to this brilliant post, the concept and utility of sidereal time has been around a very long time. The length of a sidereal day was even calculated to a surprisingly high level of accuracy some 1,500 years ago!

Here are two surviving sidereal clocks that were made “recently” – just a few centuries ago.

But who on Earth would use sidereal time?

Astronomers would.

Most people don’t look at the boring old Sun all the time. We look out to the stars and galaxies far, far beyond our solar system. If an astronomer wants to track the position of Betelgeuse day after day, she can record the sidereal time that she saw it, and know that it’ll be at the same ascension at the same sidereal time the following day. Brilliant!

Mariners and Astronauts would.

They can fix their location even when the Sun is not visible, by observing the position of the stars and calculating their position back from the current sidereal time. Life-saving!

Oscilloclock Labs would.

Because we can.


In the next post, we’ll take a look at the build. What hardware went into this Astro Clock? How on earth does it tick? Can you figure it out?

New Year’s Resolution!

Q: “What’s your New Year’s Resolution?
A: “Why, 1024 x 768, of course!”

Geeky jokes aside, here at the Oscilloclock lab we DO have a form of New Year’s resolution! 「日進月歩Nisshin-geppo, which loosely translates as “Steady progress day by day“, reflects the goal to complete the the once-in-a-decade re-design work, and resume crafting beautiful Oscilloclock products. It also highlights confidence that issues currently facing the wider world will be overcome, one step at a time.

In keeping with local traditions, [Oscilloboy] wrote the slogan in Japanese calligraphy. But there, tradition ended and true joy began! Behold, courtesy of an Oscilloclock VGA Core assembly, Oscilloclock’s 2021 New Year’s resolution on a beautiful old 7-inch oscilloscope!

The Setup

After choosing an appropriately meaningful four-character phrase for our resolution, I asked [Oscilloboy] to write out the characters. Bucking with tradition, we used standard white A4 paper instead of calligraphy paper. The ink took more time to dry, but we wanted to maximize the contrast.

[Oscilloboy] demonstrates his prowess in Japanese calligraphy. Right: the finished product!

After scanning the handwritten characters and inverting the images, I created a rolling video in 1024 x 768 resolution. (See? The joke at the beginning of the post about resolution was serious, after all!)

I then played this through an Oscilloclock VGA Core assembly, which is essentially a graphics card that allows you to use a beautiful old CRT as a rudimentary computer display. (For earlier write-ups, see VGA display… On a 3″ scope tube! and The VGA Cube! .

The assembly used here features a late prototype of the Revision 3 Power Board, which I have been working on for almost a year. I won’t go into all the bells & whistles yet. Stay tuned!

A VGA Core assembly – displays monochrome images from VGA, SVGA and XGA inputs

Unlike a permanent Oscilloclock conversion (see the Gallery for examples), this was only a temporary setup. The VGA Core was positioned externally, with the harness routed into the 7VP1(F) CRT via the rear of one of the side panels. No invasive procedures needed!

Just LOOK at that beautiful CRT socket – brown Bakelite!

No VGA socket on your ultramodern slim notebook of choice? No problem – use an off-the-shelf HDMI to VGA converter!

And voila – the final result! Japanese calligraphy on a vintage 7″ oscilloscope!


About the Model – A rare 1963 Nitsuki Oscilloscope

Nitsuki is the brand name of Japan Communication Equipment Co., Ltd., a specialist in television and microwave broadcasting systems. The firm’s English name was originally Nihon Tsushinki Co., Ltd., so you can see how the Nitsuki moniker came about.

Check out this exquisite cap on the pilot lamp!

By 1963, the Japan domestic test equipment market was mature and quite competitive. English language labeling had become stock-standard. This scope is one of very few units I have ever obtained that has Japanese labeling. How appropriate for today’s display!

Japanese labeling – a rarity!

Some of the higher-quality oscilloscopes of this era featured flip-latches and detachable side panels, for easy access. See the Toshiba ST-1248D for another example. These scopes are infinitely more enjoyable to work with and show off than scopes with a slide-out chassis.

This model is also quite unusual for its time in that most of the components are located under the chassis! The valves (tubes, if you prefer) are even mounted horizontally. Nitsuki used very robust construction techniques, including very tidy cable lacing.

In fact, their design was so robust that the scope functions almost perfectly today (except for some triggering instability), yet there is no evidence of major repairs in the last 57 years!

Back to its natural self – a nice old 7-inch 1963 oscilloscope!

Like what you see?

The Oscilloclock lab struggled in 2020 due to worldly events, but NOW – day by day, step by step, the newly designed Oscilloclock boards are at last taking shape! Does your New Year’s ‘resolution’ for your next project specify 1024 x 768? Or perhaps you’re into displaying fancy calligraphy on vintage CRTs? Let me know.

And as always, see previous posts and the Gallery for info on other unique creations!


Critical Update 25 December 2021

Well. Christmas Day 2021, and [Oscillowife] — the chief editor, advisor and critic extraordinaire — just informed me that I had placed [Oscilloboy]’s first character「upside down when creating this post! Apologies to our readers for the gross oversight.

It’s been 12 months! But better late than never to eat humble pie…

A Cathode-ray Cat

For those cat lovers out there, let me present one beautiful kitten who knows his place in life: bedded down amongst some beautiful Brimar CRTs!

Cathode-ray Cat

This picture, submitted by an Oscilloclock aficionado, proves that there ARE others with an intense passion for CRTs out there. And this group now includes the feline species!

Anyone out there have a capacity-controlled canine? An electron-excitable echidna? Or a filly with a phosphor fetish? Let me know!

Brimar Beauties for Plug & Play

[Atif] is quite fond of his custom Oscilloclock Model 1, originally supplied with a bright green Brimar SE5F/P31 CRT. He just loves its crisp, clear trace! But wouldn’t it be great if he could plug-and-play a different CRT, to suit his mood of the day?

[Atif]’s Oscilloclock Model 1 SE5F with P31 green phosphor… Could we change the mood?

More specifically, could I create a second display unit (the acrylic tube on the left) using a CRT with a soft, long-persistence blue trace? And could he just swap the units around at will, without having to make any changes to the control unit?

Absolutely! But to make the 2nd unit completely compatible for plug-and-play, we’d need the same SE5F type CRT, with a different phosphor. Looking at Brimar’s catalogue, this CRT was available in several phosphors – including a P7 blue. This is the same as used in the original Prototype, and it’s really good at showing off those exotic trailing effects!

SE5F P7 specs

So the hunt began…

Now, this particular P7 CRT is famously difficult to come by – whether new OR used.

The most common piece of old equipment employing the SE5F was the ubiquitous Telequipment S51 oscilloscope, but the overwhelming majority of those had a P31 phosphor CRT installed. Indeed, of all the demonstrably working S51’s posted on eBay in the past decade, I have never seen a single one showing an obviously blue trace!

After many months of scouring auctions, suppliers and CRT fanatic colleagues across the globe, I managed to locate one SE5F/P7 in highly questionable condition – and located in Italy! With Google Translate as my friend, negotiations ensued, and – taking a substantial risk that the CRT would actually function – the unit was duly purchased and shipped.

A dirty, slightly rusty SE5F/P7 CRT – snatched from the brinks of destruction in Italy

Often, well-used CRTs exhibit scratches, spots, or burn-in marks on the internal phosphor coating. Fortunately, this CRT’s phosphor proved unblemished! And powering it up (for the first time in decades, most likely), it proved to be electrically faultless, as well!

It works!

Beautifying the Brimar

You may think that cleaning a CRT is hardly worth writing home (or the world) about.

But this specimen was slathered in sticky, gooey tape residue, which had to be carefully removed. My chemical of choice for this is, believe it or not, eucalyptus oil! Not only does it remove the gunk, but it also serves to clear up any nasal or bronchial congestion that the technician may have at the time. Two birds with one stone!

The more difficult issue was removal of the graphite coating. During manufacture, the front-most 8 cm of the glass of each SE5F was sprayed with a conductive graphite-based paint. Why? To make a high-voltage capacitor with the spiral accelerator anode (the beautiful green stripes) and similar graphite coating on the inside of the glass. By connecting the external coating to ground, the thrifty circuit designer could avoid using a separate (and expensive) high-voltage filter capacitor in the anode power supply!

External and internal graphite coatings
form an effective high-voltage capacitor!

Why remove this coating? Because during use, it gets scratched and marred, as the above photo shows. Such a messy CRT could never be worthy to mount in a clear cast-acrylic case for an Oscilloclock! In addition, the coating obscures some of the attractive spiral accelerator anode, and blocks the incredible view of the trace from behind. And regarding circuit design, we at Oscilloclock NEVER scrimp – the Power Board has oodles of filtering capacity without relying on a graphite coating!

While eucalyptus oil is also effective, it can get rather expensive in the quantity required – especially as the Oscilloclock lab is not conveniently located in Australia! The more reasonably priced chemical of choice here is nail polish remover. As always, there is a side-benefit – the nasal passages are assuaged by a delicate floral scent during cleaning, and fingers have an arguably nice smell that lingers for quite a while!

Joking aside – gloves, open windows, good ventilation, and safety glasses (in case the CRT implodes) are key ingredients for this process!

Eucalyptus oil and nail polish remover has done wonders to this Italian-sourced beauty!

Onward!

Having found the perfect CRT, [Atif]’s plug & play unit is now well under construction.


Epilogue – “Good things come in threes”

It’s not good just getting one CRT. What if [Atif] wanted a spare? What if I wanted a spare for my venerable Prototype clock? Following from the Italian success, I continued a further 6-month hunt, and managed two achievements.

The first was a Telequipment S51b unit located in the U.K. that was non-functional, but that I suspected may have a P7 phosphor installed. How could I possibly suspect this? Well, perhaps this is an art rather than a science, but there were several tell-tale signs:

  • The way the phosphor looked under the camera flash or ambient light
  • The colour (or absence) of the graticule (the plastic cover in front of the CRT)
  • The fact that I got a double when I rolled the dice to decide whether to take the plunge or not!

The seller of this unit was not willing (or perhaps not technically able) to extract the CRT, check the CRT type, or ship overseas. Fortunately, my colleague in the U.K. was more than happy to receive the scope at his end. Thus arranged, when the unit arrived he extracted the CRT and confirmed that – sadly – I had purchased a P31 CRT.

Oops, it was a P31 – the dice did not roll in my favour that time!

But I shipped it across anyway, and the CRT tested well. Rescuing a functional SE5F/P31 from eventual demise was still a worthy accomplishment!

The second achievement was prompted by an auction listing for a “Brimar SE5F”, but with little indication as to the phosphor. The photos of the label (see right), even with subsequent close-ups provided by the seller upon request, were not conclusive.

The image shows two characters beginning with ‘P’. It looks like “P1”, which is another extremely common green phosphor used in many CRTs since the beginning of time. However, we saw in the catalogue earlier that Brimar only supplied GV, P7, P31, and P39 phosphors as standard. It is unlikely that any equipment manufacturer would have requested Brimar to produce a custom CRT batch using the less-exotic P1 phosphor… Leaving the P7 as the only likely candidate!

Convinced, the CRT was duly shipped across and tested – and lo and behold, success! A spare P7 was safely procured.

And with that, the long saga of this CRT hunt closes. As they say, “good things come in threes!”


Like what you see?

Cathode ray tubes used to be manufactured in all shapes, sizes, and colours. Some prove harder than others to find! But if you prefer an exotic creation, don’t give up – there is something for you out there, and here at Oscilloclock we will find it.

As always, see previous posts and the Gallery for info on unique creations!

Quake News!

Fake news – a common keyword these days. Fortunately, Oscilloclocks do not display fake news. But wouldn’t it be handy to see quake news on an exotic scope clock? This is the challenge [Atif] gave me – and one year and many grey hairs later, here is the result: The AfterShock Clock!

This custom-crafted Oscilloclock Core Duo assembly is a unique first in several ways:

  1. It’s the first scope clock ever that pulls in and displays real earthquake data!
  2. It’s the first scope clock ever that puts a dual-beam CRT to good use – one beam for the clock display, and the other for the earthquake and map overlay!

Earthquake display

The AfterShock Clock’s WiFi module connects at regular intervals to two public APIs (servers) to collect the latest earthquake events. It then feeds earthquakes to the clock’s quake gun controller, rotating quakes every 30 seconds. Cool!

(Note: flickering is due to camera effects and is not visible to the human eye)

Of course, there is the usual wide variety of standard clock screens to cycle through! The quake map’s beam is automatically dimmed for most of the screens, giving a soft ‘watermark’ effect.

Dual-beam CRT

The E10-12GH CRT used in this clock is certainly not mundane!

Beautiful spiral PDA lets you really see inside the cavity!

Nothing beats a dual-gun CRT for intricacy… (except a quad- or pentuple-gun CRT!)

Oscilloclock Core Duo

Atif wanted to create his own case, so he initially asked for an Oscilloclock Core. But currently a single Core set does not provide control, deflection, and blanking circuits to drive TWO electron guns… So he had two choices:

  1. Wait an eternity for me to redesign the boards to fully support dual beams.
  2. Get started now! Simply put two Core assemblies together, with some degree of inter-control and removing any redundant circuits.

Atif chose the latter – and the Oscilloclock Core Duo was born!

WiFi setup

Setting up the WiFi connection is easy – just connect a device to the clock’s administration SSID and pull up the admin page. (To foil any would-be hackers out there, the admin SSID is available only for the first 5 minutes after power is applied.)

Then, access the admin URL and configure the connection to your home router:

There are a million other advanced settings to tweak things such as quake polling interval, quake magnitude filters, maximum quake age before purge, and other geeky aspects….

Oh, I forgot to mention – the clock also synchronizes time against an NTP server, eliminating the need for a GPS module.


Like what you see?

Do you go for electron guns? idolize intricate electrode assemblies? Have a filament fetish? Or just want some quake news? This kind of clock might fit the bill. Let me know!