Exploring SKALA: Chernobyl Reactor Control Computer

In this episode of Computers of Chornobyl series, we will talk about the mighty SKALA system, that controlled the RBMK reactors.
This is the first-ever documentary about its design, architecture, operation, and software. It also tells the story of how it was preserved for posterity and reveals, what is common between it... and a control computer of Apollo spacecrafts.
It took us nearly half a year to collect the information and technical details about SKALA vintage computer, and what we uncovered has completely reshaped our understanding of how the Chernobyl Nuclear Power Plant operated. We sincerely hope you will enjoy it and learn as much as we have!
What you will find in this episode:
00:00 - Introduction
01:20 - How we saved SKALA
02:16 - This is why a special computer is needed to control a reactor
03:00 - A brief history of SKALA creation
04:00 - What is inside?
05:00 - This is what we discovered in archives
06:58 - Architecture and principles of operation
07:58 - A quick look to software of SKALA
09:00 - DREG and PRIZMA programs. Multi-machine mode.
11:15 - Control panels of DIVT engineer. Request devices.
12:49 - Reactor control room controls - mnemonic displays, selsyns, loggers
17:55 - The truth about the last signals of reactor 4.
19:55 - How DREG program worked.
21:14 - DIIS-2000 - SKALA’s sister computer system
22:33 - Outro
Get our limited-edition SKALA poster: / 91648436
Support our research work and projects:
Patreon: / thechernobylfamily
Donate: www.buymeacoffee.com/chernoby...

[@ChernobylFamily]

SKALA POSTERS ARE NOW AVAILABLE! Order here: kzbin.infoUgkxzxTC5WABX-371XwLcHOEMcyNVBioXVA6

[@SaraMorgan-ym6ue]

but it lets the reactor explode so um no not in a million years.🤣🤣🤣🤣🤣

[@ChernobylFamily]

To be accurate, the machine had nothing to do with the explosion at all.

[@SaraMorgan-ym6ue]

@@ChernobylFamily oh yes it did

[@ChernobylFamily]

@SaraMorgan-ym6ue proofs? IAEA has a different opinion. Read INSAG-7 report. Sorry: I prefer to operate with the expert-level data to make conclusions; and operation of the computer system was reconstructed up to each second. There were no flaws in it; the flaws were in totally different things. ;)

[@andrewhillis9544]

​@@ChernobylFamily SO Was The CHERNOBYL DISASTER Caused By COMPUTER Or HUMAN FAILURE Or A COMBINATION Of BOTH ? ? ?🤔🤔🤔🤔🤔🤔🤔

[@michaeljones6256]

The computer resource limitations you discussed are not only in the Chernobyl Skala system but also in the USA 3 mile island reactor installation. It was noted that the priority data output from the computer was lagging very far behind during the melt down emergency. I am thankful for the chance to see this equipment which may have been lost to the scrap yard without your intervention.

[@ChernobylFamily]

Thank you for those details!

[@gabbyn978]

I guess, the measurement reports came in so fast that the computer could not handle it in real time. Real Time operation was a big thing in the 1980ies; and not many computers could do it. Seeing it from today, these 'high tech' machines were slugs, but there was no better technology available, because it had not yet been developed. Don't assume that a Commondore 64 could have been able to do it. A memory of 64 kilobyte of RAM would be nice; but processing the reports of 1661 channels in real time was beyond its capacity. Also, all of the east European countries were suffering from a boycott, they could not order western computers, as they were categorized as potentially useable for weaponry; so they had to construct their own computers. They even had to develop their own systems. If you think of that... they sent their Soiuz rockets into space with that technology.

[@andrewallen9993]

The computers of the age like the HP 2100 using the Real Time Environment software could process the data fast enough but the Teletype HMI device couldn't keep up so the output was stored in memory to be slowly printed out by the teletypes.

[@ChernobylFamily]

@@gabbyn978 check the part of the video closer to the end; this is what I meant - signals of SUZ were bufferized and there is a chance at some point during 10-15 seconds after reactor 4 explosion that buffer got an overflow. We will make a separate episode on this.

[@elkiton]

Hi, I was a tech salesman with DEC in the seventies. One of my clients took me on a tour of a UK powerplant. I was intrigued by the use of Deva drum storage devices, they being long out of fashion, and a couple of minicomputers from a competitor which seemed a strange configuration. Getting the gen on them it seemed they were used for some tests in the installation and test phase, but we're so good at monitoring the operation they were left embedded in the final installation and could not be removed once the plant went live. One guy had a single job, sourcing spares and keeping the drums operational.... After that tour I swore I would not go within 20 miles of that plant, and never did.

[@Skaldewolf]

all these hand-soldered elements, the ton of wire-wrapping and these wonderful ferrite-core memory-elements. The amount of work that must have gone into this system is staggering.

[@ChernobylFamily]

And imagine to manage this... or UPGRADE this, when they had to connect DIIS...

[@jhoughjr1]

This is a viral historical treasure to preserve as much as possible.

[@ChernobylFamily]

Thank you!

[@ayitsyaboi]

This is insanely cool, thank you. Even with my understanding of computers and programming it still blows my mind that people figured all of this out with the limited technology they had. Both hardware and software.

[@ChernobylFamily]

Thank you!

[@jeremyphilipjohnpenrice462]

This is truely the salient point as to why the unmonitored unmoderated section brlow thd fuel rods reach where the Reactors core started thd runnaway condition which were initiated with ghe pushing of the AZ5 button. For thise 8 seconds every was completely unmonitored to the actual conditions which caused the massive nuclear explosion. Jeremy Penrice. Electrical & Instrumentation Engineer.

[@mrcontroversy222]

im building a decent sized shope...i have a room for my pc gaming...one wall will be OLD monitors and computer interfaces! jesus i made need a video of the shit ive collected

[@ChernobylFamily]

DO IT!

[@keeganplayz1875]

It's incredible how modern computers barely take up space, but 37 years ago they took up an entire room! SKALA was very powerful for It's time!

[@ChernobylFamily]

Especially if we pay attention to the fact it is a highly specialized machine, so not a computer in a general meaning.

[@paulbrown3302]

MS DOS had already released for PCs by this time computers were desktop

[@ChernobylFamily]

....and what is wrong ?

[@BlackEpyon]

Actually, SKALA would have been well behind the technological curve by the time of the reactor #4 accident. Massive wire-wrapped TTL-based mainframes like this developed in the 60's were being phased out of service by the 80's, as the smaller and more power efficient MOS and CMOS based integrated circuits were becoming more and more reliable. At least in the west.

[@lucasrem]

@@BlackEpyon Soviets were able to develop good systems for their industry and power plants. Not able to develop consumer system only.

[@thiagozanolomainente76]

This video is amazing and deserves a million views🎉

[@ChernobylFamily]

Frankly, it took us three weeks of drawing, animating and editing non-stop, so really, really hope for this!

[@samjanssens1509]

no, atleast 2 million, more than the fake vid

[@ChernobylFamily]

@@samjanssens1509 thank you. In fact, as more people watch, as more it motivates us for new epic stuff to make. Greetings from Ukraine!

[@minty_Joe]

@@ChernobylFamily Outstanding job on the videos. Thank you so much! I hope all is well and safe during these difficult times. God bless you and peace be with you. Love from United States of America! Glory to Ukraine! Glory to the Heroes! 💙💛🌻💪☮

[@ChernobylFamily]

Glory to heroes!

[@JB52520]

Wow, that system has a strong creepy vibe to it (in a good way). The control rooms were part of the computers. The operators were integral parts of the system, enclosed within it, their minds filled with codes. It must have been an overwhelming experience.

[@ChernobylFamily]

It was. People who worked with this, told us, all this felt like a city, it was very special.

[@vladislavstanimirovic9650]

I remember visiting my father's workplace, an analog telephone exchange that had a similar computer room, although much, much smaller, but similar in a way of having the tape reels, teletypes etc. Usually, around such machinery various stickers were placed with sort of short "reminders", and one of them said, "Remember, you are the brain of the machine". Your comment reminded me of that, it unlocked a 30yr old memory. 😁

[@therandomytchannel4318]

Akimov and everyone else in the room probably had to get special education to run these systems hey 🎉

[@ChernobylFamily]

@therandomytchannel4318 not probably, but definitely. As far I remember, it required 8 years of study.

[@TheSonicfrog]

Well done! I have an affinity for old computers, when I was in the US Navy aboard the USS Jason AR8 (a repair ship) circa 1974 I was responsible for operating a Univac AN/UYK 5V computer, used primarily for tracking parts and work hours. Not a single IC anywhere, everything was transistor/diode logic, with about 4096 18-words of ferrite core memory. I/O was four tape drives, a teletype for a console, a huge chain driven printer, and an even bigger card reader/punch. Surprisingly, the system had a COBOL compiler, and I wrote a small program to accept punch cards and print out a list of everyone serving aboard.

[@ChernobylFamily]

Thank you so much for sharing this!

[@DreamGrandDragon]

I’ve been following the Chernobyl for disaster for years. Thank you for giving me more insight on how this system and how everything works. Always has been a curious fascination. I’m glad I found this channel.❤

[@ChernobylFamily]

Thank you! Much more to come!

[@PonczekORIGINAL]

You can't imagine how long i've been waiting for any sort of documentary on SKALA. Thank you!

[@ChernobylFamily]

Glad ypu enjoyed it!

[@mikebailey783]

This is brilliant; one of the most captivating documentaries I've seen in a while. Superb use of archive photography, and great to see such effort put into the illustrations. And thank you for going into such detail on the various processes and conventions involved.

[@ChernobylFamily]

Thank you!

[@alexhajnal107]

_"thank you for going into such detail"_ The more detail the better! It's one thing to see what a machine does but it's much more interesting to learn how it does it.

[@ChernobylFamily]

Very right

[@jakemeyer8188]

My wife grew up in Slavutych. Her mom was one of those engineers at Chornobyl, but she got there in 1988; 2 years after the accident. She worked with the remaining operational reactors (obviously). I myself am OBSESSED with retro computing such as this, and especially the reactor computers of the era. I'm dying to create my own replica reactor control room... Edit: if it wasn't clear, this video is AWESOME. MASSIVE thank you for this!!!

[@ChernobylFamily]

Based on what you told, we believe you will like what will come next...) Thank you!

[@williamrekow7513]

I hope the people there are well, or that they have gotten somewhere safe.

[@Meshuggah27]

Thank you so much for this video. My mind is absolutely melted. I am a Sysadmin, and the tech back then was insane! I cannot imagine the amount of engineering that had to go into this.

[@ChernobylFamily]

You are so welcome!

[@KeritechElectronics]

You're going full-on CuriousMarc here! What a magnificent system and video. And the comparison with the AGC DSKY is on spot here. Same thought crossed my mind. Speaking of the DSKY... just look at all these electroluminescent displays - another feature these systems had in common.

[@ChernobylFamily]

Well, frankly we don't follow CuriousMarc, but we believe he does some cool stuff :) as for displays... they are breathtaking in action, and they arr so huge...

[@senilyDeluxe]

@@ChernobylFamily You sure you aren't CuriousMarc's long lost twin brother? :-)

[@ChernobylFamily]

Bhahaha that start to sound like an Indian movie :)

[@mikolasstrajt3874]

CuriousMarc literally repairs Apollo computers with his friends. This is very similar thing.

[@BlackEpyon]

CuriousMarc and his group have gotten into restoration of some Soviet-era space hardware, and he's familiar with operating and restoring big TTL-based mainframes like the IBM System 360, 308x series, etc, so there's a lot of collaboration potential.

[@lincolnfirmo8221]

Thanks for your dedication and work in sharing this precious information with the world! Greetings from Brazil.

[@ChernobylFamily]

Thank you! Glad that you liked!

[@vladimus9749]

Seriously. I've always wondered what role the computer had in the disaster. Never been able to find much until now.

[@ChernobylFamily]

So happy it was helpful!

[@alexhajnal107]

@@vladimus9749 Seems like it did its job very well. Without the telemetry it recorded it would have been much harder to determine exactly what happened and why.

[@johnnyzippo7109]

I clicked subscribe , was surprised I wasn’t already , having watched several of your offerings multiple times . Thank you again , I will join the Patreon at end of month.

[@bassybossy]

Amazing view of the system and thank you for saving and explaining it. The disaster is an incredibly personal story for many that the hardware and software underlying it all is often overlooked. Looking forward for more on this!

[@ChernobylFamily]

Thank you! There is much to tell, and we will work on this...!

[@phildem414]

Great video! I was searching for info about SKALA for years. Here in france, Tchernobyl was a tragedy that marked everybody. The RBMK reactors are prety well known and understood but cold war, USSR computers remain misterious. I went to the science museum in London ans they a stunning BESMM6, impressive machine for sure.

[@ChernobylFamily]

BESM6 was THE machine...)

[@MarkMcCluney]

That array of analogue gauges is extraordinary. Thanks for showing us Alex, this is a fabulous documentary, so fascinating and just brilliantly presented. Thanks to both of you for all the effort you put into this channel.

[@ChernobylFamily]

Thank you so much! We are thinking to get a couple of selsyns to make a demonstration of them in action by recreating one of those meters.

[@bradmiley]

Дякую за це фантастичне відео. Я був зачарований Чорнобилем з часів катастрофи, яка сталася, коли мені було 16 років, і здачі важливих іспитів. Я знав, що радіація досягла моєї країни, і що чудове весняне повітря, яким я дихав, також було (трохи) радіоактивним. I am from the UK, and have always wanted to visit the reactor, Pripyat, and the DUGA installation, but im disabled now, and I dont think I could handle all the walking!! I send you Blessings and Love from the Northern UK, to you and your family. Stay safe!. Slava Ukraine! 🇺🇦 ❤️

[@ChernobylFamily]

Thank you so much, my friend, it is so valuable for us! Take care and get ready for new videos that will tell even more secret stories! Glory to heroes!

[@bradmiley]

@@ChernobylFamily Thank *you*! That was an awesome video - truly. I have never seen SKALA, only heard about it. Your video explained in great detail this mysterious system. It's almost unbelievable, a computer so tiny (memory/processor speed) could run a complex nuclear reactor. But they can only do what *humans* tell them, and the experiments conducted in late April 1986 pushed *everything* beyond their limits. A friend of mine, in 2007, made a music album (with a few videos) about the disaster, and gave everything (documents, recording diaries, video and music masters) to a Chernobyl children's charity. It was released at the date and time of the disaster in 2007 - the idea was, anyone born then would have reached the age of 21 (a milestone in some European/Western countries). He gave them full permission to do whatever they wanted with the album. I think there are a couple of music videos on KZbin to this day. Sorry for rambling! I was gifted a copy of the album so I tend to think of it, the music in my mind, when I talk about April 1986. Stay well my friend, love from Northern UK ❤️🇺🇦❤️🇺🇦 Героям слава. Слава Захисникам. Слава Народу. Слава Україні!! 🇺🇦🇺🇦🇺🇦🇺🇦

[@ChernobylFamily]

Thank you for sharing all this. It is... so touching.

[@ChernobylFamily]

Do you have a link to or a name of the album?

[@cameronmoylan712]

Excellent move stepping in to save the system. Every person has the power to do something when they notice a bad decision is about to be made.

[@ChernobylFamily]

Well, I do not overestimate my contribution, but that was the case of being in the right place at a right time.

[@ClassicalRips]

Thank you so much for making this video! For decades I ran in to the same issue that you did, no resources I could find ever described the SKALA system at all; documenting industrial control systems like this is very important to retro computing history and is a very overlooked sector for computer historians!

[@ChernobylFamily]

Glad we could help! But, we are going to continue.

[@ZakHooiTM]

This is beyond cool, always wondered what computer system was behind chernobyl. Will there be any chance that the Tapes and drives that still exist to be read it and archived? Maybe some day the SKALA architecture / system can be reverse engineered and be emulated with the original software Proud to be a patreon member for this channel

[@ChernobylFamily]

They stand and do exist. Well, will suggest that idea.

[@TheErilaz]

​@@ChernobylFamilyMaybe it could be posted on github?

[@jasonmurawski5877]

They may be standard 8 track tapes. They look like rebranded IBM compatible equipment, and in that case the computer history museum has an IBM 1404 that can read the tapes and send it to a modern computer

[@JCarey1988]

I second the request for reading and preserving any tapes!@@ChernobylFamily

[@revsnowfox5798]

Eh, it was an industrial control system, I doubt there's much value in extracting the raw numbers from those tapes. The same kind of applies the emulating the SKALA, it's not an ordinary "retrocomputer", it's an automation and control system for a nuclear power plant, how do you emulate it?

[@michaelmoser4537]

Great video! Also: SKALA was not based on ES EVM (soviet copy of IBM 360), this was not typical of soviet computer systems of that time. Also turns out that you absolutely needed this computer system for normal operation of the RBMK reactor, as RBMK had an unusually large positive void coefficient. RBMK doesn't keep water inside the reactor under pressure, now you end up with fewer water within the reactor, as the water evaporates. This creates temporary voids. Now water is also a neutron absorber, so that these voids are resulting in a stronger chain reaction and increasing the thermal output. Eventually the whole thing exploded... The book "Midnight in Chernobyl" by Adam Higginbotham mentions an accident at the first installation of the RBMK reactor in Leningrad: "On the night of November 30, 1975, just over a year after it had first reached full operating capacity, Unit One of the Leningrad nuclear power plant was being brought back online after scheduled maintenance when it began to run out of control. The AZ-5 emergency protection system was tripped, but before the chain reaction could be stopped, a partial meltdown occurred, destroying or damaging thirty-two fuel assemblies and releasing radiation into the atmosphere over the Gulf of Finland. It was the first major accident involving an RBMK reactor, and the Ministry of Medium Machine Building set up a commission to investigate what had gone wrong. Afterward, the official line was that a manufacturing defect had led to the destruction of a single fuel channel. But the commission knew otherwise: the accident was the result of the design faults inherent in the reactor and caused by an uncontrollable increase in the steam void coefficient. Sredmash suppressed the commission’s findings and covered up the accident. The operators of other RBMK plants were never informed of its true causes. Nevertheless, the commission made several important recommendations, to be applied to all RBMK-1000 reactors: develop new safety regulations to protect them in the event of coolant loss; analyze what would happen in the event of a sharp rise in steam in the core; and devise a faster-acting emergency protection system. Despite their apparent urgency, the reactor designers failed to act on a single one of these directives, and Moscow promptly ordered more of the reactors to be built. The day after the Leningrad meltdown, the Soviet Union’s Council of Ministers gave its final approval to construct a second pair of RBMK-1000 units in Chernobyl, expanding the station’s projected output to an impressive 4,000 megawatts" Interesting if SKALA was supposed to have fixed these inherent instabilities during low power loads, but no - it was only a monitoring and recommendation system that was not designed to control the reactor directly.

[@user-um6rt7zz3h]

I am an electronics engineer and it was very interesting to learn about this control and data processing system. There is nothing on the Russian-language KZbin about this system. Yes. You're right. Regarding the fact that the parameter time was output to the printer after processing. In one of the videos I heard from one of the panel board engineers, the time of changing the parameter and its subsequent indication.......... I was shocked...... 18 seconds!!!!!! So, really, the processing time after receiving the change signal and its indication (printing) is huge. 18 seconds is an eternity for a reactor.

[@ChernobylFamily]

We've asked a few engineers; this thing with 18 seconds was not a common thing. It was slow, but not that slow.

[@teatimee]

This was really fascinating and well made. I hope that lots of other people get to see your work.

[@ChernobylFamily]

Thank you! We hope for this very much.

[@bobbysenterprises3220]

First video I've seen of yours. This was absolutely mind blowing. Thank you. I would love more on these details you eluded to.very well done and nicely paced with great footage and explanations

[@ChernobylFamily]

We are very happy that you liked...! Wait for more!

[@BartManNL]

I recently stumbled onto this channel and can only say it is AMAZING! Thank you for making these videos!

[@yagomg7790]

I remember reading about SKALA a few years ago (when my chernobyl obssesion). I was bummed by the low amount of information about the computer. This video really made my day if not my week.

[@ChernobylFamily]

We are so happy to hear this...! Stay tuned, more to come!

[@Takyodor2]

I had no idea that I needed this in my life, but now I'm hooked! Super interesting information, and very well put together, thank you for making this (and saving the computer).

[@ChernobylFamily]

Glad that you liked! There will be much, much more content like this - and in meanwhile, check our previous episodes!

[@robertwatsonbath]

This is really interesting! So SKALA was much more than a computer solving complex reactivity equations but also an enormous real-time data acquisition system too - measuring and logging everything as well as looking for anomalies from "normal" operations?

[@ChernobylFamily]

Yes, it is a very good and correct definition you proposed. Actually, it comes from the meaning of its name - "the system of control and automatization".

[@AmauryJacquot]

and they did all that with 20kB of ram... current systems are so much bloated...

[@ChernobylFamily]

200, as those 20 were is in octal system.

[@filipmecir262]

@@ChernobylFamily Still crazy - PLC I use for home automation has 20 MB RAM... Thanks for this video.

[@GuyFromJupiter]

Like modern day SCADA

[@F3Aer]

Thanks for the making of this video: it is incredibly interesting. Also, discovering, analizing and showing pics and video from that time demands a lot of time and work. Again, thank you very much for doing this!

[@ChernobylFamily]

Glad you enjoyed it! More to come!

[@eduardocarvalho1547]

Thanks! I've been waiting for a detailed video about the Skala computer for years. I hope in the future you make more videos about Skala and also the other less known auxiliary systems of the NPP.

[@ChernobylFamily]

More to come!

[@NickFizzard]

This video HAS to blow up. The immense amount of knowledge, research, and incredible amount of skill to apply here has absolutely paid off. This is HISTORY you're making, man!! You earned another subscription! 😄👍❤️🇺🇦

[@ChernobylFamily]

Glad you enjoyed it! Well, it took quite a time to make it, it is true :)

[@SuperBicycleRepairMan]

Thanks for the detailed and considered look at the RBMK control system. Plus all the work that you have put in. All the best with your future projects :).

[@ChernobylFamily]

Much appreciated! Check previous episodes!

[@SmokinGoodd420]

History should never be forgotten. Saw this on YT main page recommends . Well done !

[@ChernobylFamily]

Thank you! Check our previous episodes, and if you have a possibility, join us on Patreon - there is 10x more interesting stuff on Chernobyl and its amazing tech.

[@anomalousbob9361]

This video is perhaps one of the greatest documenting videos I've seen on old computers! I genuinely loved every single moment; congratulations for such a beautiful production!

[@ChernobylFamily]

Thank you! A continuation is coming soon!

[@keith_5584]

Thank you for commissioning and documenting this for us. Seems very well sculpted for an early age computer!

[@ChernobylFamily]

Thank you for coming!

[@AndrewRump]

The most amazing KZbin video I have seen in a very long time. A fantastic find and definitely something that needs to be stored for eternity - and your explanations just gave me so much new information about Chernobyl. keep up the great work.

[@ChernobylFamily]

Thank you so much!

[@costindan6180]

Greetings from Romania, amazing video, you pieced together so much info about this system… great work, we’re all grateful. Thank you!

[@ChernobylFamily]

Glad it was helpful!

[@djdomi6583]

Excellent video! I was always interested in SKALA and how it worked. Thanks for the video! :)

[@ChernobylFamily]

Glad it was helpful!

[@youtubasoarus]

Awesome video! Love to see how these old machines worked. The complexity is mind boggling. Thank you for making this and your hard work to research it.

[@ChernobylFamily]

Get ready for much, much more!

[@youtubasoarus]

@@ChernobylFamily I can't wait! This is fascinating and exciting!

[@ChernobylFamily]

For now, check previous episodes, some are pretty special :)

[@johnnyzippo7109]

Thank you and your associates so much ! I have been waiting for this video , this documentation of this computer mainframe for a very , very long time ! Bravo ! Simply Bravo !

[@ChernobylFamily]

You are very welcome! Subscribe!

[@PercyPruneMHDOIFandBars]

What a FASCINATING video! This is an area of the subject that really doesn't get the attention it deserves. You explain it well for an old tart like me who doesn't really understand computers. However, when you mentioned the request system I also started thinking about Apollo. I do hope you do more of these. Thanks for sharing your hard work!

[@ChernobylFamily]

Glad you enjoyed it! There will be much more here, stay tuned!

[@0xbenedikt]

Fascinating. I never really looked much into this and didn't expect that they actually had such a complex DAQ and control system. I thought this was all done by hand with manual gauges and some discrete analog electronics.

[@ChernobylFamily]

So much still to discover. We personally, although knew it is far more than a computer, did not expect it is THAT big in its role.

[@alexhajnal107]

@@ChernobylFamily And all that in 20k words. A lot of people today don't realize just how much one can do with that. I'm really interested in learning more about the V-3M's architecture (CPU, buses, etc.); maybe a follow-up video? Edit: That's 20k addresses of 24-bit words. Still impressive though.

[@monad_tcp]

@@alexhajnal107 "A lot of people today don't realize just how much one can do with that." Its basically driving hardware, nowadays everything is emulated by software, and we have 50 years of layers on top of layers to make things super complex and use a lot of ram. That machine had none of that, just bare assembly code, you don't even need to have code to display things, there's actual physical display devices. The amount of things you can do with very little RAM when the hardware itself does the heavy lifting is amazing.

[@monad_tcp]

I'm surprised that it did had a kernel/user division.

[@ChernobylFamily]

I'll just add a correction, those are 20 octal KB, so roughly 200 in binary. It used 24-bit words.

[@techn1kal1ty]

So they were essentially dual-core, each core having 20K cache and 8K shared RAM, with ECC? Controlling VMs via machine code, with hand-punched, punch-tape BIOS? These computers may be light-years behind modern specs and functionality, but way ahead of modern computers in charisma.

[@ChernobylFamily]

20K octal 24-bit words even...)

[@moebius2k103]

Very cool video, it's obvious that a great deal of research went into this. Well done.

[@ChernobylFamily]

Thank you! This year will be a continuation :)

[@FancyP24]

This is such a niche interest for so many people, and you just filled a void of knowledge that I didn't even know I had. Thank you for these videos, amazing graphics and explanations!

[@ChernobylFamily]

We are really happy it was interesting :)

[@JapanPop]

I wish I could give 100 likes. It was so touching to hear about Mrs. Pripyat feelings. You impress me in keeping on making good videos like this during more conflict. Ukrainian people must be very tough. Your people have overcome so much in the past 100 years.

[@ChernobylFamily]

After all, our research is a piece of that "normal" that keeps us sane.

[@ChernobylFamily]

After many questions received, we will make a series of Patreon posts with more details and bonus materials about SKALA and control room systems - you are welcome to join us! Link is in the description of the video.

[@MegaWatt_Lab]

А буде українська озвучка відео?

[@ChernobylFamily]

@@MegaWatt_Lab та от багато хто просить, але ми поки не знаємо, як це зробити по часовитратам. Це фактично означає зробити повністю нове відео кожного разу, ледь вдається поки це робити.

[@MarkLynskey]

Great Video, the sheer engineering that went into this is amazing, especially the monitoring system.

[@ChernobylFamily]

Glad you liked it! More to come!

[@Jappmannen]

As a former instrumentation engineer at a ASEA ATOM BWR reactor this is impressing as hell! Especially if you think about that the computer must handle over 1600 analog channels at the same time (probably even more if you count in such parameters like steam and feedwater temperatures, steam pressure, feedwater flow and probably some data from the turbine). And then I haven't even mentioned that RBMK reactors have that possitive feedback loops which means that the control rods must be actively controlled all the same time in order for the reactor to maintain a consistent power level.

[@ChernobylFamily]

Thank you so much!

[@SebastianGalletto]

Another amazing video from you. It is great as a piece of Chornobyl history, and also as computer history.

[@ChernobylFamily]

Thank you for these motivating words! Seriously, it is very important for us.

[@Larslegos]

It's so cool they decided to save it. I've always wanted an explanation of infrastructure like this because most of it is very vague and doesn't get into how it really works. This video deserves so many more views!!

[@ChernobylFamily]

Thank you! Hoping for this!

[@IlyaSTM-uv5gy]

Большое тебе спасибо за сохранение ценной информации и интересную подачу!

[@ChernobylFamily]

:) you are welcome - and more to come!

[@AnthonyFrancisJones]

Brilliant! Thanks so much for making this!

[@ChernobylFamily]

Get ready for a continuation next weeks!

[@telumatramenti7250]

"Skala" (plural: "Skaly" - stress on A)means more in Russian than "rock". Original semantics of the word aside modern use specifically denotes the upper part of tall mountains that is bare rock. The word is never used to refer to individual rocks, for example - a boulder that needs to be moved when clearing a road or a rock you could pick up with your hands. The word's frequent poetic use is possibly the main reason why they decided to stick with that abbreviation. I can see that NASA's taste for abbreviations was certainly shared by the Soviet programmers. This is certainly a very unusual, high value educational video. I thought SKALA was forever lost to history by now. My first ambient music track "Deus Ex Machina" was dedicated to this ancient apparatus ☺The scifi part of me envisions a future museum of computers where all of world's important and iconic historical computers, with "Enigma" and Turing's computer which cracked it, Apollo's computers, 1980-s Soviet ЭВМ and so on. And of course, - this amazing beast.

[@ChernobylFamily]

Thank you for sharing! Do you have a link to your track?

[@flaviotrash9693]

I has been waiting a video like this. Thanks

[@ChernobylFamily]

Glad that you liked! There will be much more about this equipment in the future...)

[@neolerades2987]

12:37 - I have built a clock from the same VFD displays as were in the panel in SKALA, nice to know that the same parts were used in chenobyl. VFD is IV-22. In my language skala means rock.

[@ChernobylFamily]

Cool!

[@Trottelheimer]

Thank you for this fascinating insight into the control systems of the reactors! As a computer enthusiast and professional since the early 80s, and with an interest in the history of computers, this was right up my street - subscribed 👍

[@ChernobylFamily]

thank you! wait for continuation...)

[@ATTomMan]

Thank you guys, incredible stuff, such rare info. Had no clue, why there such small number of subscribers on this channel. Thank you for so detailed review of many types of equipment. Truly rare things you have access to. I`ll use some references from cannel, for props modelling, in future METRO game series. Greetings from Kyiv.

[@ChernobylFamily]

Happy to hear that..)

[@lucasrem]

Great Video ! I was asking Russian friends for years to do this, but everyone did say, then i will be arrested as a spy. But there are people that did restore the SKALA systems, and specially the SKALA at Chernobyl ! Great uploads.

[@ChernobylFamily]

Here in Ukraine things are far easier...)

[@allancopland1768]

Excellent video.Very many thanks for posting this.

[@ChernobylFamily]

Glad that you liked! More to come!

[@DreamHeaven]

Indeed very interesting video. Thanks for your work ! Deserves much bigger exposure

[@ChernobylFamily]

Thank you very much! More to come!

[@AlyaraArati]

I think this is the first video of yours which I've seen. Bravo! There's a ton of stuff about computers that I don't understand, but this is fascinating nonetheless! My friend has been educating me about Unit 4, and I have to say, it's very interesting!

[@ChernobylFamily]

Unisual computers are just a part of the great story of Chornobyl - as unique conditions required unique solutions. Thank you! There is much that will come here, and about Unit IV as well :)

[@klaas-janrozema5396]

Amazing content. Thank you very much for this unique and almost forgotten story. For me as a computer engineer it is mind blowing what they did with available computer hardware back then. The Chernobyl story is engraved in our collective memory, we'll never forget.

[@ChernobylFamily]

Thank you so much!

[@waywardtraveler9896]

I’ve watched hundreds of videos on Chernobyl and never heard of this. Great job very informative

[@ChernobylFamily]

Thank you! Check our newer episodes as well!

[@florianlacrampe4361]

Really amazing work ! Thank you for all ! SKALA design is very elegant :) Best greets from France

[@ChernobylFamily]

Merci!

[@GenerationAI2024]

Thank you so much for this in depth info on this beautiful computer. Just love those old proprietary computers :)

[@ChernobylFamily]

We are really happy you liked it!

[@leopiipponen7693]

Very intresting video complexity computer systems :)

[@ChernobylFamily]

Glad that you liked!

[@tamahagane1700]

Absolutely stunning. Thank you for helping save this piece of history.

[@ChernobylFamily]

Glad you enjoyed it! And thanks for your warm words!

[@DerTyrann1984]

Great video. This computer was amazing, it reminded me when I flew the Embraer 190 where everything is also controlled by the computers, with self tests, failure detection, dual channels that switch automatically. All you have in the cockpit is a digital interface.

[@patrykx4577]

I also read almost anything what i could find avout chernobyl disaster. And cannot find any info about skala system in english speaking intetnet. Thanks a lot for this excellent presentation

[@ChernobylFamily]

So glad you liked it!

[@germancaperarojas4023]

Man. What a gem! Greetings from the other part of the world. This is amazing. What a nice retrocomputer dive into how the USSR created their first main frames and control systems.

[@ChernobylFamily]

Thank you! Greetings from Ukraine! Check our previous videos and stay tuned for new :)

[@raulegido]

This video is awesome and very informative. I really appreciate the time you took to make this as easy understandable as possible about a so complex subject. You earned a subscriber. Keep up the good work!

[@ChernobylFamily]

Glad it was helpful! Check our previous episodes..)

[@raulegido]

I will. Thank you@@ChernobylFamily

[@mikolajkaraczyn6382]

Hi, really great video! Thanks for sharing with us this unique and rare informations. I would like to see continuation about this topic :)

[@ChernobylFamily]

This year it will come;) stay tuned :)

[@mikolajkaraczyn6382]

@@ChernobylFamily great, I will (un)patiently wait for it! I'll check other your videos :)

[@mikefochtman7164]

Very interesting. I worked in US BWRs from the mid 80's. They had data gathering systems that tracked the power levels throughout the core. Like the RBMK, during refueling individual bundles were shuffled based on their previous exposure 'burn up'. Before this time, some plants just recorded the data on tapes and sent them to a vendor that would read/ analyze and project future thermal performance and 'fuel shuffles'. Yeah, those old 'band printers' were not particularly fast. Ours were 300 lpm (lines per minute) but the alarm typer was a simple dot matrix that was much slower.

[@ChernobylFamily]

Thank you for sharing all these details.

[@gregrudd6983]

The move over to DEC VAX's for near real-time would have been a huge step forward.

[@joshflugel]

Magnificent video for the tech geek community. Mad respect for the scientists and engineer that created these machines in those old days.

[@ChernobylFamily]

Thank you! And if you would only hear with what respect they still talk about it!

[@OstlerDev]

It is amazing to see this system preserved, THANK YOU for your work!! I found it highly interesting!

[@ChernobylFamily]

I just want to underscore, that although our word had a weight, and likely was the final drop, the preservation is the decision of the amazing collective of the power plant. Those guys are awesome:) Thank you for your words! It is highly motivating!

[@nrdesign1991]

The teletype segment sounded so incredibly rhythmic and musical

[@ChernobylFamily]

YESSS. Frankly, when I've been editing that, made a rewind i think 10 times to listen to that again :)

[@krisztiangyarmati2144]

Hello! I would really like a more detailed summary of the SKALA system, looking at the implementation of the connections, the communication between the individual units, and the software implementation. Go to these, or to any of them :) I really liked your video, thank you!

[@ChernobylFamily]

Thank you! We will make this as soon as we will be able - due to wаr it is not really possible, but hopefully things will change.

[@RyderUwU]

I'd be cool to have a dump of all the alarm sounds and such, it's hard to find but honestly I find them cool. I'm kinda building a game around managing a reactor and this stuff always inspires me

[@ChernobylFamily]

....planned!

[@RyderUwU]

@@ChernobylFamily hell yeah!

[@ChernobylFamily]

We are going to buy a bunch of actual selsyns - exactly that type that is at the NPP, and do something cool, just saying:)

[@RyderUwU]

@@ChernobylFamily ooh already can't wait for the showcase if that's planned for it as well. If you don't have the hardware to test them who knows you could use an Arduino or maybe the KZbinr curiousmarc knows something

[@ChernobylFamily]

Curiousmarc, curiousmarc, curiousmarc...))) we have a few research institutes in contact, just saying;))))

[@allanren0116]

Very very awesome and informative video. Thank you for persuading them to keep the original machine and making this awesome video.

[@ChernobylFamily]

We are glad that you liked! In a month or so will be epic continuation, so stay tuned!

[@rgarito]

Been waiting for this video... And you did not disappoint! Excellent!

[@ChernobylFamily]

Glad you enjoyed it!

[@fi11222]

Very cool documentary. Thanks a lot. Maybe you could think about a part 2 including more info about the H/W architecture of the SKALA and its monitor/OS. You made a comparison with the AGC. Did the SKALA also have a prioritization of tasks like the AGC did? Some remarks you made that measurements might be delayed waiting for a "processor window" seem to indicate that it did. How exactly did this task scheduler work?

[@ChernobylFamily]

A continuation will come, though that will take a lot of time in the current conditions. I'll check on your questions with engineers and come back.

[@AgentSmith911]

Very impressive technology for such a long time ago!

[@ChernobylFamily]

Completely agree!

[@Kevlux86]

Great video! Great visuals, explanations, added graphics too. Looking forward to seeing your next one!

[@ChernobylFamily]

Thank you very much!

[@georgH]

I had wondered about these computers for years, thank you so much! Amazing channel!

[@ChernobylFamily]

Glad that you liked that!

[@enoladeveu3653]

Wonderful video! Thank you very much. I've been waiting for it for a long time. 20K RAM, no CRT no keyboard, writing programs in machine language. That’s it. That's what real men do.

[@ChernobylFamily]

Well said!

[@neil4306]

Great video. Thank you

[@ChernobylFamily]

Thank YOU!

[@ChefAtPlay]

This is incredible! Thank you so much for creating and sharing this.

[@ChernobylFamily]

Thank you..! More to come!

[@iangrimshaw1]

A really fascinating video, well done. Subscribed and thank you.

[@ChernobylFamily]

Thanks for the sub! Check our previous episodes, we have a few documentaries and other interesting Chernobyl things as well.

[@iangrimshaw1]

Diving as we 'speak'. @@ChernobylFamily

[@DKTAz00]

Very very cool, amazing how much space these things used to take up

[@ChernobylFamily]

Thank you!

[@nojbik]

Good job again Alex.Some people thinks that USSR computers were piece of crap, but in fakt they were working well and reliable for their purpose. Thank You for all Your reviews

[@ChernobylFamily]

They were a piece of crap with some brilliant exceptions :)

[@vitalyl1327]

@@ChernobylFamily have you seen ЦВК, by any chance?

[@ChernobylFamily]

Mmm... i am afraid I need a hint

[@vitalyl1327]

@@ChernobylFamily another Soviet computer from that era, slightly newer than SKALA (1970, AFAIR), built using ferrite core memory and discrete ICs. It's still deployed in the S-300 complexes. Was quite a fascinating design for its time - very RISC-like architecture with quite a deep pipeline, SMP with hot-swap for CPUs, also extensive self-testing features like in SKALA. It's sad that only military, nuclear and aerospace applications got unique Soviet designs while civilians had to cope with poorly copied western computers...

[@ChernobylFamily]

@vitalyl1327 unfortunately, this one I did not have a chance to see, but it sounds impressive.

[@iwanjones7334]

As usual, a fascinating account of how SKALA worked. I can't thank you enough for this amazing video.

[@ChernobylFamily]

Our pleasure!

[@Thor110]

Amazing work as usual, this is the video that deserves 2 million views!

[@Silanael]

I was always wondered if that kind of signal CRT display actually existed or not. Thanks for clarifying that! Also, if you have any technical documents of SKALA, I'd be most interested in adding them to a Chernobyl-archive I'm building. Thanks for the great video!

[@ChernobylFamily]

With all wish, there are no and I'm afraid won't be so far.

[@RobertEliason]

I remember the Barsebäck NPP having a teletype based backup system back in the 80's when I interned there. Nothing as cool as the C64 I had at home :P

[@ChernobylFamily]

Haha..)

[@littlesparklerofficial]

You've done a very good work, to show how these controlsystems worked. Thanks for sharing. Best greets from germany.

[@ChernobylFamily]

Thank you for coming!

[@alexzaslavskis4623]

Really great work , looking forward for other videos. Many thanks. Sveiciens no Latvijas 🇱🇻

[@ChernobylFamily]

Thank you so much!