My New NASA Minicomputer!
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- čas přidán 28. 06. 2024
- A couple of months back, a very kind gentleman by the name of Godfrey reached out and asked if I wanted to take a crack at restoring an old minicomputer he had. After seeing the pictures, I was 100% on-board, because not only is this Data 620 a brilliant, transistorized machine, it also happens to have come from NASA. Being built in 1965 or 1966, it was used at NASA right through the entirety of the Apollo program, so it’s entirely possible this big, blue, beautiful beast actually contributed to sending people to the moon!
You can find the brochure here:
archive.org/details/TNM_Data_...
If you want to support the channel please hop over to Patreon:
/ usagielectric
Also, we now have some epic shirts for sale!
my-store-11554688.creator-spr...
Come join us on Discord and Twitter!
Discord: / discord
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Intro Music adapted from:
Artist: The Runaway Five
Title: The Shinra Shuffle
ocremix.org/remix/OCR01847
Thanks for watching!
Chapters
0:00 Welcome Mr. 620!
1:55 Stripping and repainting
4:47 Reassembly
8:04 Rearranging the room
9:14 Looking dapper
11:08 A dive through the brochure
17:40 Memory Power Supply
19:18 I/O Control
21:10 Core Memory
23:31 Front Panel
25:54 Central Processor
28:54 Hellorld NASA-kun!
32:51 Happy Fuzzy New Year! - Věda a technologie
![[004] CHIP $9 computer, and PocketCHIP](http://i.ytimg.com/vi/-ikur8fzBQ0/mqdefault.jpg)
Is there is a "HELLO MOON" program lurking in the core. (Or is it HELLOON?)
Heloroon?
Hell no!
or even HELLO LOON 😂
I feel like it would be more “HELLON!”
MSC stands for Manned Spacecraft Center, the original name for Johnson Space Center, which isn't too far from you. You might give them a call and see if they have any info in their library or archives concerning this machine.
What a sweet machine! Like a straight PDP-8 but more rare and noble. Fantastic job at rejuvenating the cabinet!
So when is CuriousMarc making a trip to Texas, or SystemSource in MD?
@CuriousMarc Part of me really wants you to read the core memory module before anything else happens. I’m just scared of the possibility of losing anything that must be on there!
@@kanishkavikrampurohit It's a nice thing if you can preserve it, but it's not a realistic expectation. And most of the time you can't do anything with the core dump, it's just binary RAM. We were lucky that we could bring up our AGC on emulated memory, and Mike was able to figure out the program it ran when it left that core imprint. Most of the time this is not possible.
@@CuriousMarc Have you and your team thought of building a fully functioning AGC replica?
That split opening chassis for the CPU was fascinating. Never seen anything like it and definitely quite ingenious.
If you have a multi billion dollar budget you can do a lot of fancy things.😁
I've seen stuff like that, and even done better, but only on extremely expensive stuff. Stuff that makes your eyes pop once you hit the price sheet.
Given the date of make for the computer it's more likely that machine might have been used in the Gemini program. Which ... in my opinion ... would be even more cool.
I agree. The timeframe matches. Possibly, it could also have been involved in the Ranger program (Block 3)? This would make it even cooler, so little remains of humanities first tries at close-up views of the moon.
It's always incredible to me how these computers are in such good condition for being so electrically fragile. When the CPU cabinet folded open my jaw dropped.
The computer could have been part of the Apollo Command Module or Lunar Module simulators at JSC. Checking online, the simulators used Data Control's DDP-224 and DDP-116 that were made by Honeywell. Possibly, they replaced the DATA 620 computers for more horsepower for the simulators. Also, the DATA 620 could have been part of the Gemini program's spacecraft simulator.
Would that mean there's a chance that an AGC could be hooked up to it? Or other simulated equipment like communication test computers? I smell a collaboration with CuriousMarc brewing here.
Don't know why, but I find it funny that the pinball machines are never moved. Priorities.
The front panel buttons remind me of my mom's old blender from the 50's.
Mmmmm, transistorized computer goodness. Always great to see a backlit pushbutton front panel, not a common style, but a classy choice nonetheless. The NASA lineage is the icing on the cake!
I love the early days of computers.... it was like the wild west. All the different companies and designs. So many ways to solve the same problems. Good times! Today I sit and watch this on a flat panel and an Intel NUC that fits in my hand..... in MY lifetime, and it isn't over yet. Just ASTOUNDING!!!!
Interestingly, this is the exact architecture of the old Honeywell 1648, or 316, AKA the famous Honeywell Kitchen Computer of Neiman Marcus fame. A, B, and X index register. 32k ferrite core memory, 16 bit, octal. I believe that was circa 1969. The instruction sets look remarkably similar from what I recall. Sense switches too. I learned BASIC, FOTRRAN IV and DAP-16 assembler on those machines. We ran dozens of users in timesharing mode on the 1648A running Hazeltines, ADM-3A's, ADDS, and ASR-33's at 300 and 1200 baud (we patched the OS to do 1200), which was actually 3 - 316's functioning as Job, Control, and Communications interconnected by 1 byte ICCU bus. 12 meg removable 10 platter packs. I wonder if that was inspired by this machine?
That's cool because it bumps the documentation availability right up.
Tons of them seemed to merge together at different times. Trying to confirm more than one but said Varian was acquired by Sperry. But, Sperry was not Acquired by Honeywell until 1986.
Wow, it's like people were running business and science labs on clockwork, hearing stuff like that! How could you run timesharing on 32K and 12MB!? I know they even did it with 8K and 5MB on some machines, but it's just so unbelievable, now I'm typing this on something like a dozen Cray-1's all wired up on one chip.
Also the same computer architecture used to develop the first MRI machine.
I remember the core store machine I used at university in 1975 still had my programs loaded when I can back from the summer break! 60 years is a bit longer but as long as the cores didn’t get hotter than their Curie temperature down in Houston dat should still be there - bureaucrats withstanding!
Just a quick painting tip: brake clean is fine, but it can leave an oily residue. As a final step go over the area with denatured alcohol to get the brake clean residue off.
Oily residue from Brake cleaner can be dangerous.😁
My friend you got the most epic fridge in town
I worked with the successor to this computer, the Varian 620f, as an engineering intern at NASA Dryden Flight Research Center back in 1977. The machine was installed in the Remotely Piloted Research Vehicle (RPRV) lab, though it was largely unused at the time, having been replaced by a newer Sperry/Varian V77 as the flight characteristic computer, translating ground cockpit inputs into PCM signals transmitted to various pilotless aircraft (not toys!) for flight research. The supervisor of the lab gave me access to the 620f to practice assembly language programming. As I recall I would use the TTY to punch a paper tape of my ASM code, then configure the console to load the Assembler program tape (from the same TTY), then load my source code from tape and spit the output back to the TTY. It was glorious fun for a 19-year-old kid and the start of a long career in computers and electronics. Although they share the same 620 designation, the 620f was light years ahead of what I see being worked on here. Though the 620f also used core memory, the CPU was almost completely integrated circuits and the whole package (CPU+RAM) took up less than half the space of this old 620 CPU alone. They do seem to share the same architecture and instruction set from what I can see, but the Varian version was much more like a PDP-11 operationally than this ancient beast. I can't wait to see its transformation into a working system. Cheers!
Some of the core memory modules of the AGCs that my favourite nerd Mike and rest of Curious Marc handled had actual data in them: they managed to find the latest lat/Lon position out of them when reading out the memory modules 😂 so you could be lucky 👍👍🦆
yup, core is hard core, as and quite possibly even more non volitile than semi conductor rom....if data still exists on this machine, it may be earlier than the use of semi conductor rom...i wonder what the earliest still accessible to us now semi conductor rom application would be...
Usagi has visited Curious Marc (he was in one of their recent videos), looks like we'll get more collaboration between the channels, which I always enjoy.
@@DaedalusRaistlin That is true. I bet there will be a collaboration is getting the memory units ready to read any remaining contents. Considering that this was a NASA machine from the Apollo era I would say this is quite likely!
Isn't it possible to read the core mem through the front panel? If yes would not be an automated frontpanel with 16bit data bus connector an easy way to read it.
@@stefans8325 It's not so much a matter of whether or not it can be read through the computer, its whether or not the circuitry is in a functioning state that wont destroy the contents of memory as soon as you power on the computer.
Mr Nasa would be Nasa-san. Using -kun indicates that you two are familiar with each other. I don't think you're there yet, David. ;)
All: "How many projects do you want to start?"
Usagi: 🐇
Just looking at all that hand-assembled wiring and jammed together cores makes my joints throb in sympathy. No WONDER these things cost millions in 1960s dollars for fairly low performance compared to ICs only a few years later. I am proud of you for snagging this Dave, but glad you aren't going to commit to work on it yet. You have too much at hand with your current minis and mainframes.and I REALLY want to see that Centurion printer up and running! Thanks again for sharing the journey with us! Happy New Year!
IIRC @CuriousMarc has a friend that has an entire setup he used to read core-memory out of the Apollo computer they restored. So it's plausible that his setup could be repurposed to read yours too. Unfortunately not all core memory is built the same as Marc has given excellent discussions of.
Sadly no, thats core rope memory.
Whoa, a tremendous lot of work! Just recombobulating the office was very intense but the effect is splendid. Your nerdcave is even more impressive now :)
A beautifully built computer, and the opening CPU reminds me of the G15 or HP 150A. Definitely some great engineering.
I wonder if Marc's team or people at Smithsonian know something about what it could be used for. Or maybe NASA's own historians?
Oh my gosh... I can only applaud you for taking on such a challenge. You are BRAVE, man! Wow.
Yes, well beyond anything that I would try. I worked with DEC pdp-8i's quite a bit and had one in my living room for years. Since it was the computer I learned on in school I had always wanted one. It was fairly easy to work on compared to this that David will work on. I hope he gets it running.
as soon as that CPU rack flew open horizontally, my eyes flew open vertically
Amazing piece of history you have there.
My 2005 PowerMac G5 is looking quite modern now. And fast. And small. And efficient. And light.
As much as I wanna see this thing getting put back in working order, I'm just happy that another piece of history has been saved from the scrap yard.
You describe this machine as a bridge between vacuum tube and IC based machines, perhaps it'll be my gateway drug into finally appreciation crazy vacuum computers like the Bendix!
Back in the day, I've thrown out hundreds of these cards mainly because they contained (at the time) worthless germanium transistors and were usually coated in epoxy which made salvage nearly impossible. So, I would take the silver-mica and mylar caps, the power resistors and any other goodies that I thought useful or worth the time to strip.
On the marker-marks on the front processor pane: You may find them impossible because (again) back in the day, permanent markers were actually permanent not like the joke Sharpies we now have. These old markers contained xylene and toulene so they literally eat into the paint! Anyway, have fun and thanks for sharing!
Another amazing project, you could do with more of you or more hours in a day, a huge amount of work.
pjcnet
Old people need a community, work together on project, restoring the past. Trains, Cars, Mini and Main Frames too now.
That teletypewriter with the big ears by the book shelf looks really happy
It's obvious Star Trek TOS user interface were based on that era of computer. I just love that look of the panel.
Ты крутой, мужик! Собери как можно больше этих старых "динозавров". Не дай им умереть.
^ translation: "Man, you are cool! Collect as many of those "dinosaur" systems. Don't let them perish."
People of Russia, Ukraine and Belarus are enamored with your work as well as the rest of the world!
Man, if I could get 5% as much work done as this I'd be delighted. The sliding door in our shower room has been broken for like 5 years and we just put up with it... Just can't motivate myself to go "beast mode" and get stuff done like this.
Had to share my knowledge. Core memory is a read write cycle. Because if it wasn't it would be impossible to branch back to any address it had just read. For the clunky ASR33 you'll need a serial interface, the cards for that may in there already. Nice looking PDP 8. One of the things I did at DEC had a PDP 8 to my left. I was doing test and repair on a KV8I interface driving a Tektronix vector graphics display where I could play Lunar Lander. Off a paper tape! But I had a PC05 high speed reader punch on the PDP 8. I worked at DEC 1969 thru 1975. My experience on DEC equipment ran from PDP 8 thru 11/780 VAX systems. Loved the 11/45 system, absolutely a pleasure to do repair work on. Right down to the failed IC, not circuit board level repair, including core memory. Finally OH look a TEAC 4010 back there. I've got two of those in my reel to reel collection of over twenty machines including two all vacuum tube units. And I do repair work on them. And on this NASA system the two extra bits to a total of 18 were probably parity bits, one for each byte. Which would require 18 bit core memory. Enjoyed the video too, thanks.
Actually it's read-modify-write. As core memory reads are destructive. I wanted to work at DEC, but they sent me an invite 6 months after I had started my first job.
@@timradde4328It's both, if you read an instruction you don't modify that instruction. When the core is read they set a flip-flop or not depending if it-s a one. That flip-flop can be changed on a modify cycle. If not then the FF feeds the write circuit inhibit circuit to prevent the core from being set to a one state if it was original a zero. If the source and destination are the same memory location, then a read-modify-write occurs. Otherwise there's nothing to modify.
@@rpk5568 There is still the possibility of a modify. That's how core work. Read-Maybe modify-Write. That's how it has to work. Thus when you read it has to be re-written as the contents destroyed. Ok, during instructions that's fine. But what about an increment. You read the data. It's now gone. You need to add 1. And write it back. Come on, it's not that hard. Just a generalized view. Of course you can prevent modification but overall I've always seen it described as read modify write. Can we drop this now as I don't plan to argue with you about it.
Wow, wouldn't it be incredible to be able to get this machine and the Bendix to talk to each other !?!
Amazing what a bunch of common electrical components accomplished back than.
For that permanent marker, you might try going over it with dry erase marker. It's a trick I was told many years ago that does work pretty well, though not necessarily perfectly.
Or go over it with another permanent marker (Sharpie, Marks-A-Lot, etc.), then use your usual marker removal solutions. The wet marker solution (dry-erase or permanent) will rehydrate the old marker doodle and make it easier to remove.
ive used that trick, someone took a sharpie to a white board and by using a dry erase marker over it the permanent marker came off easily, due to its age it might not fully remove it but it should at least thin it out.
Permanent marker comes off with ethanol. some common or garden vodka will work well, as with methylated spirits
Fully agree with@@the123king. Tried IPA in the past as well and was surprised simple ethanol worked much better
Why don't give WD40 a try?
Re: the castors - we had the same problem with a brand new open-frame rack. Had to get a metal plate fabricated that would not bend in when the rack got loaded.
When you said rotating drum memory, I hit the like button. Yup.
Just to connect this to earth: just because the marketing brochure shows where you would connect a disc drive to it, doesn't mean that there ever was one. That could have just been an aspirational thing, like "if we ever connect a disc drive to it, it would go on this bus." But then, by the time I saw these in the early 1970s under the Varian brand, it does seem like they were a popular machine, so they may have had all of these peripherals available, just probably from other companies. I mean, everybody had Calcomp 560 plotter interfaces, because those were very simple and ubiquitous, while there's no telling what "standard" they used for the disc or tape drives.
the solvent in a new sharpie can remove a lot of old permanent marker pigments, seems weird to put new on top to remove the old but it works
that brochure is absolutely beautiful
Any other OCD people thinking about the rust left on the under side of the rack? Will be watching to see if it gets sanded off and primed in the future.
I'm someone who loves computer science and electronics from the 60s, 70s and 80s, thanks for your videos. Greetings from Italy.
Congratulations on the Machine. Now only a relay logic machine is missing! ;-)
He has relay calculators he built.
@@maskddingo1779 I mean a big one from the 50's.
@@rweninger oh yeah. That would be cool! Just making sure you knew he has some vids on the one he built👍
Do I sense a CuriousMarc collaboration episode in the future? I mean old NASA related electronics and him go hand and hand!
Well you know exactly who you need to call for this one! Mike (forget his last name) from CuriousMarc's channel. Would be awesome to see both of them over there with you working on it!
The way the light/switches are spaced as 1-3-3-3-3-3 on the front panel is indicative of an octal architecture.
It seems likely that the unpopulated slots in the memory and processor sections would only be present in an 18bit machine.
A fascinating machine, I look forward to seeing this being restores. I love seeing these old classics being brought back to life and I look forward to every new post from you. Wishing you and your family a Happy New Year, thanks for all of your work and past uploads, looking forward to many more in the new year ;)
Talking about addressing the teletype with a party line I/o system…. That’s quite some pun!
27:35 Whoa such magic 🪄
Looks like one of those projects where I'd push the whole thing into a large industrial parts washing machine and just run it for a week.
The March 1967 Technical Facilities Catalog Volume II (Report # NHB-8800.5, VOL. II Section 11, Page 55) makes makes reference to a "Telemetric Incorporated Model 620 Decommutator" at the Houston Manned Spacecraft Center's Digital Techniques Laboratory on July 15, 1966. This Lab also had a DEC PDP-5 with a CME-8 memory extension and two DECTAPE magnetic tape units. Lots of pulse signal generating equipment in the lab as well.
Nice find! From what I was able to turn up, it appears they also used a Varian 620/f as part of a data analysis system in the Mississippi Test Facility Earth Resources Laboratory. Apparently when the computer was first delivered there were severe problems with the CPU that "caused significant delay in program assemblies and checkout" that Varian were unable to fix, so they ended up just installing a replacement. Just glancing at the documentation, the ERL-DAS sounds like it was quite a sophisticated system for its time.
Sources:
Earth Resources Laboratory Data Analysis System Final Report - October 1972 (Report # 1746FR-1 sec. 1, pp. 6-8; sec. 2, pp. 2-4; sec. 3, p. 2; sec. 4, pp. 1-2, 4)
A Procedure for Automated Land Use Mapping using Remotely Sensed Multispectral Scanner Data - January 1975 (Report # NASA TR R-434 pp. 32-33)
Looks like they also used a Varian 620/i to control the McDonald Lunar Ranging System. One of the documents I found even has a program listing!
Source:
A Description of the Control Program for the Lunar Ranging Experiment - November 1969 (Report # TR-70-064)
A Description of the Time Interval Measurement and Laser Control Circuitry for the Lunar Ranging Experiment - November 1969 (Report # TR-70-049)
one tip for removing really old magic marker... draw over it with a new marker. It can help dissolve the old stuff. Usual disclaimer of try a small bit first...
Happy new year from Melbourne Australia (at 11:45pm NYE 🎉)
I’m very happy you have another super exciting project (like you needed it!!) and looking forward to what you bring us in 2024.
well it's another 6.5 hours here in central europe lmao, happy new year to you!
That splitting chassis...absolutely jaw dropping!
That’s a nice find, thanks for sharing. Machines like this may have been used as sequencers on automated test equipment.
Looking forward to that restoration. I guess you will bring in CuriousMark on this project, seeing that they did a lot of work on NASA-stuff with core memories. Good luck, and I really don’t know where you get your energy from. Thanks for helping to keep this very important part of history alive.👍👍👍👍👍👍
Really liked looking at that glimpse of the IBM 2311 disk drive. ;D around time stamp 16:37
Thank you for all of the incredible videos this year! Best wishes for the year ahead.
I knew the moment I saw it, that I'd seen this machine before. What threw me off for a bit was that I knew it as a Varian Data Machines 620. A real piece of history.
You're gonna need a bigger office for all these awesome machines.
So glad you decided to do this video. Looking forward to seeing what you discover along the way.
P1 immediately thought of "The Adolescence of P1" a novel written in the 1970's about a computer network that becomes self-aware.
if only I was closer. I could learn so much giving a helping hand.
Thanks for sharing this amazing machine with us, I really look forward to my Sunday morning computer fix. Have a Happy New Year!!!
That's a pretty cool piece of computing history you found! Looking forward to you digging into it, learning about it, and bringing it back to it's former glory!
It’s the perfect vintage (ahem) and I look forward to the eventual progress, though I fear this might be the most challenging on yet. Bon courage !
Beautiful job on the repaint.
hello mr. usagi, I wish you a happy new year, thanks for all the great content!
LOVE this. Thank you for what you are doing!!!! It is really important work.
If only you could find someone who designed, built or operated this machine, that would be an EPIC talk if he was still able to remember clear enough.
It reminds me of a quote from a former NASA engineer that they weren't smarter than the current generation of NASA engineers but this project must've been so much more impressive than we're seeing now, since we're now only trying to go BACK where these guys have been over 50 years ago with this technology.
That panel works similarly to the Univac 1219 at our musuem in VCFed. The Register and address lights are also the input lighting up when pressed and halted or showing current data of the execution. Great find! cant wait to see it work one day
Oh man this is amazing and a huge amount of work! You'll have to pop in at CursiouMarc's with your core memory and have Master Ken get the data back 😁
What a gorgeous computer
Oh yes, magnetic core memory. Fascinating stuff, but I think everyone's relieved that solid-state memory/ram were invented. It didn't happen overnight though, so it's good to have these legacy machines around.
Happy new year from Switzerland. I wish you only the best working tubes and lots of motivation to repair this museum computers.
A 60-year-old program used on the Apollo project? What a find that would be!
If one is still there. It's still an impressive, historical piece. Ganbatte kudasai, Usagi--San! (Good luck, Mister Usagi!)
Backing up that memory will be an interesting challenge!
I'm really grateful you showed this to us!
Thank you for all the great project videos in 2023. What amazes me about all the systems you have is the notion that many very clever folk thought about, designed, developed and built these years ago, paving the way for the technology we have and use today. Fascinating and brilliant in equal measure. All the best for 2024 keep safe and well. Nigel.
Nice Cosmo!
Not many left.
Nice work! I am sure Curios Marc will be watching,
I am in awe! This is going to be another immense project, on the order of the Centurion. JSC has a history office that may be of help. Though I imagine their main concern is matters of space, they may have something of use. This is so exciting. I'm foaming at the mouth!
Happy fuzzy new year David!
That is a beauty.
18:00 - Most excellent 🚀 - I’m impressed with your commitment and confidence by prepping the rack etc prior to working on the internals. Your optimism is contagious. Love your channel. Happy New Year 2024 and best wishes moving forward. 😊
Wow David, you just exponentially exploded your work load, thanks for sharing, it's very interesting to see some of these early machines, especially, where the individual modules are made from descrete components, should be possible to build an emulator , might need to be a community project, you will probably need some help to restore this one, best of luck, I know what it's like to take on a seemingly unsurmountable task. It's like feature creep, but in the form of donnations / restorations. Happy new year mate !
Data 620? For some odd reason that rings a bell.
Starting the New Year with a bang (a metaphorical one, rather than a real one, thankfully)! It's understandable that it will probably be a while before it's next appearance, given how many projects you have on the go, but definitely another fabulous old computer to look forward to!
I love the "NASA Verified" sticker at 7:19. Awesome to see, knowing what NASA was doing at that time. Great video!
Edit: Having watched further on in the video, I now realize this was talked about in greater detail.
HP Computing you need, NASA, doing at that time, what did you meant ?
NASA Verified is just a nerdy thing.
greater detail, it's just a project, restoring it, you need to help him, are you in his area ? Old people should do this together !
Waow... I really hope you find something crazy on that. Destin from Smarter Every Day interviewed an actual "IT guy" from the Saturn 5... Maybe the people pushing those buttons are still around Mate. That would be CRAZY!!! Can't wait to know more
Your videos are fascinating and very Educational. I have read about things like "core memory" and computer with discrete logic boards, but seeing them and hearing your explanations takes things to a whole new level. I watch your videos in my M1 MacBook Pro, which makes for an interesting juxtaposition and which offers a nice perspective since the M1 chip was so innovative and now the one I am using is "old". Love your work!
Another awesome machine. You have enough computer power now to take us to the moon 😂
18ms for an addition. How far we have come! I remember working with computer trainers that had core memory, and were TTL based. I agree that a transistor based computer was missing form your collection. The simple fact that transistors were smaller, less heat intensive, and faster than tubes makes me wonder how powerful that machine actually is, compared to say, the Bendix.
Discrete transistor machines are terrific - they are almost infinitely repairable. There's one museum team keeping an IBM 1620 running; it is discrete transistor and they have the full complement of peripherals.
Now that's big iron. Happy New Year to you all, this is an interesting one. I like the block chart layout - it definitely makes sense but I wonder about the drawbacks.
Congratulation for finding the 'missing' link in your chain of technology history!
Thanks a lot for the '23 (and before) posts, and a Very Happy and Proliferate New Year '24!
Wow, the wiring on that front panel is incredibly neat and tidy!
It would be exciting to see it operating once again. :) This is one of a few very interesting NASA artifacts.
Ohh, taper pin backplane. Theoretically a gas-tight weld when you drive the pin on the end of the wire into the socket. Practically, a source of flaky connections, and pins that fall out! You'll need to find a taper pin insertion tool (clicks when you press on it to give an impact) and a taper pin removal tool.
a serious challenge right there!
Wow, you are absolutely CuriousMarc level now… Best of luck, really looking forward to following your journey - and all the best for 2024 from a corner of 🇳🇴…!