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.
@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.
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was installed in the Remotely Piloted Research Vehicle (RPRV) lab, though it was largely unused at the time, having been replaced by a newer Sperry/Varian V77 as the flight characteristic computer, translating ground cockpit inputs into PCM signals transmitted to various pilotless aircraft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!
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.
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!
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.
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.
@@ReneSchickbauer The sticker says MSC, which would be the Manned Spaceflight Center - today's Johnson Space Center. Ranger would've been run out of JPL or Goddard Spaceflight Center, which handles most of NASA's unmanned missions. So almost certainly Gemini/Apollo.
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!
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.
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?
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.
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!
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.
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.
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.
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. 😊
An old trick used by presenters who accidentally used permanent marker on a whiteboard - go over the unwanted marks with permanent marker and IMMEDIATELY wipe it off before it dries (use the solvent in the permanent marker to dissolve the ink). Try it on a small, unobtrusive area first.
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.
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!
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.
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.
I have a lot of experience on the 629i,622i computers as well as the v70 series. I have a neat tty program that gives memory entry search functions. The program was originally run on an SDS939 computer then modified to run on the 620i and 622i computer. I have since converted it to run on my PDP7 computer. It was normally stored on paper tape. I built a copy of the 622i from discrete IC's on four large cards... used 3000 feet of wire wrap. I expanded the registers using the extra 2 bits to add additional index registers. The party line I/O is really easy to interface. It is basically two phase... address and then data, Most of the semiconductors of this vintage are silicon... 2N2369 and 1N914 for example. Fred
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 !
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!
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
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!
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.
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!
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?
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.
I agree that this looks very similar to the Honeywell Series 16. I used the 1648 time share system as a Honeywell summer employee, and then programmed H316 systems used for data communications starting in 1971. Note that the older 516 was made by CCC - Computer Control Corporation, bought by honeywell and renamed CCD - Computer Control Division. The H316 CPU was, I think 11 boards about 8x10 inches each, filled with flat-pack ICs. The later H716 could be expanded to 64K 16 bit words, but since the instruction set used 15 bit addresses, we had to use memory bank registers when we went over 32K words.
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 🇳🇴…!
Hi Usagi, I have a tip for you to polish those grab rails, it is called *NEVR DULL* and bikers often use it on bare metal surfaces of motorcycles for cleaning/polishing. It is less abrasive and destructive then steel wool and it makes your work much much faster.
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.
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'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!
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)
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.
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 !
Interesting machine. Thanks for the information about it. BTW, there is a typo in the list of the instruction set in the manual as seen at 15:38. DAR is described as "Decrement B register". It should have said the A register. There won't be anything useful left in the core memory. Back when I was a student in Junior High school an HP2114A computer came to our school and I got to operate it. The BASIC interpreter was loaded from paper tape. We turned the machine off over night and it was ok the next morning, IIRC. However, if it was left off over the weekend the magnetic fields in the core memory had degraded and the paper tape was needed again.
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!
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.👍👍👍👍👍👍
I am shoked on the size of it, building such a thing has been an incredible ammount of work. And your attitude on restoring it to the detail, as allways do, is si valuable. Great project, thank you for sharing it!
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 ;)
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.
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.
^ 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!
25:10 to remove sharpie scribble on it with another sharpie, it will all wipe away while wet. I have never tried it with anything that old. I suppose something chemical could have happened to where it isnt soluable anymore. It could also be a dofferent formula.
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!
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.
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.
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!)
That front panel is a lot like the Burroughs B-500 I used to run. The combined "lights and switches" is basically a look at what's going on inside the processor at any moment. If you pause the operation and press a dark switch, the corresponding bit will turn into a 1. If you hold down the "reset" switch for that row and press a lighted switch, that bit will be reset to a 0. So, using that method you can enter an address and then modify the data or instruction at that address. The sense switches were a handy way to modify program execution. So, for example, if you had a GL transaction report that generated a detailed transaction report for the month plus subtotals and totals, you could signal the program to modify its operation using the sense switches. That way one program could generate a detail report for the month, a totals only report without detail, a daily report, or even an annual report with or without detail based on the sense switches that were active. This machine looks like a fun find and I wish you luck restoring it. I only have one observation that I'll pass along, based on experience with other machines. Core memory uses a lot more power than one might expect and, often, that's why it ends up divided across multiple drawers with multiple power supplies. Thanks for sharing and good luck. (Hope the back is better. )
On the label “MSC CALIB PROGRAM” the MSC stands for Manned Spacecraft Center which is the original name of what is now the Johnson Space Center. I recall as a young engineer in the late 1980s seeing an occasional MSC label here and there. Very cool!
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!
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.
The register buttons look like they work like the ones on the Univac 9400 mainframes I worked on many years ago: You press the Reset button to clear all the bits and then you press whichever buttons need to be set to a "1" state. When a bit is set, the light in that button turns on. If you press the wrong button, you have to reset everything and start over.
This video makes me sad. The largest of the Houston makerspaces, TX/RX, had probably thrown away more historical computing than it's preserved. I know that they had the training simulator for the CanadArm - they may still have the first handmade 6-axis controller that came with it, but the original 286 hardware and casing are long gone. Also gone is the Transmeta Crusoe cluster that noone was able to get functioning due to lost hard drives. It is good to see you preserving this historical computing hardware.
I'll be looking forward to this project. I have a feeling that documentation will turn up. For those who are confused by "octal machine" it is a binary machine which is made easier to handle by grouping the bits into groups or three. Hexadecimal would group them by fours. Both are for the convenience of programmers. The machine itself is binary and couldn't care less how we read the core-dumps 😇
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
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.
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.
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!”
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.
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!
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.
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!
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.
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.
Probably would've been used in both. Though initially it would've been a Gemini machine for sure.
@@ReneSchickbauer The sticker says MSC, which would be the Manned Spaceflight Center - today's Johnson Space Center. Ranger would've been run out of JPL or Goddard Spaceflight Center, which handles most of NASA's unmanned missions. So almost certainly Gemini/Apollo.
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!
That's for sure. I think he's way in over his head with this one. More work than one man could do in any reasonable length of time.
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.😁
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?
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.
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!
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.
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.
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.
I love the guards on the big pushbuttons on that front panel. Also the handles - it's so very 1960s NASA.
Amazing piece of history you have there.
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. 😊
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.
An old trick used by presenters who accidentally used permanent marker on a whiteboard - go over the unwanted marks with permanent marker and IMMEDIATELY wipe it off before it dries (use the solvent in the permanent marker to dissolve the ink). Try it on a small, unobtrusive area first.
I'm someone who loves computer science and electronics from the 60s, 70s and 80s, thanks for your videos. Greetings from Italy.
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.
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!
Thanks for sharing this amazing machine with us, I really look forward to my Sunday morning computer fix. Have a Happy New Year!!!
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 brochure is absolutely beautiful
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.
27:35 Whoa such magic 🪄
Happy new year from Switzerland. I wish you only the best working tubes and lots of motivation to repair this museum computers.
I have a lot of experience on the 629i,622i computers as well as the v70 series. I have a neat tty program that gives memory entry search functions. The program was originally run on an SDS939 computer then modified to run on the 620i and 622i computer. I have since converted it to run on my PDP7 computer. It was normally stored on paper tape. I built a copy of the 622i from discrete IC's on four large cards... used 3000 feet of wire wrap. I expanded the registers using the extra 2 bits to add additional index registers. The party line I/O is really easy to interface. It is basically two phase... address and then data, Most of the semiconductors of this vintage are silicon... 2N2369 and 1N914 for example.
Fred
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 !
Thank you for all of the incredible videos this year! Best wishes for the year ahead.
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!
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
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!
That splitting chassis...absolutely jaw dropping!
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.
Wonder wonder wonderful! Cant wait to see how you handle this
Beautiful job on the repaint.
Really liked looking at that glimpse of the IBM 2311 disk drive. ;D around time stamp 16:37
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 !
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!
My friend you got the most epic fridge in town
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 agree that this looks very similar to the Honeywell Series 16. I used the 1648 time share system as a Honeywell summer employee, and then programmed H316 systems used for data communications starting in 1971. Note that the older 516 was made by CCC - Computer Control Corporation, bought by honeywell and renamed CCD - Computer Control Division. The H316 CPU was, I think 11 boards about 8x10 inches each, filled with flat-pack ICs. The later H716 could be expanded to 64K 16 bit words, but since the instruction set used 15 bit addresses, we had to use memory bank registers when we went over 32K words.
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 🇳🇴…!
Hi Usagi, I have a tip for you to polish those grab rails, it is called *NEVR DULL* and bikers often use it on bare metal surfaces of motorcycles for cleaning/polishing. It is less abrasive and destructive then steel wool and it makes your work much much faster.
My 2005 PowerMac G5 is looking quite modern now. And fast. And small. And efficient. And light.
Backing up that memory will be an interesting challenge!
I'm really grateful you showed this to us!
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.
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'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!
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)
if only I was closer. I could learn so much giving a helping hand.
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.
LOVE this. Thank you for what you are doing!!!! It is really important work.
That’s a nice find, thanks for sharing. Machines like this may have been used as sequencers on automated test equipment.
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 !
Interesting machine. Thanks for the information about it. BTW, there is a typo in the list of the instruction set in the manual as seen at 15:38. DAR is described as "Decrement B register". It should have said the A register. There won't be anything useful left in the core memory. Back when I was a student in Junior High school an HP2114A computer came to our school and I got to operate it. The BASIC interpreter was loaded from paper tape. We turned the machine off over night and it was ok the next morning, IIRC. However, if it was left off over the weekend the magnetic fields in the core memory had degraded and the paper tape was needed again.
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!
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.👍👍👍👍👍👍
I am shoked on the size of it, building such a thing has been an incredible ammount of work. And your attitude on restoring it to the detail, as allways do, is si valuable. Great project, thank you for sharing it!
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 ;)
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?
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.
What a gorgeous computer
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!
Wow, the wiring on that front panel is incredibly neat and tidy!
25:10 to remove sharpie scribble on it with another sharpie, it will all wipe away while wet.
I have never tried it with anything that old. I suppose something chemical could have happened to where it isnt soluable anymore. It could also be a dofferent formula.
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!
So glad you decided to do this video. Looking forward to seeing what you discover along the way.
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.
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 love that mazda cosmo in the background
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!)
Well worth the intro, mate. What a fantastic bit of gear and history.
That front panel is a lot like the Burroughs B-500 I used to run. The combined "lights and switches" is basically a look at what's going on inside the processor at any moment. If you pause the operation and press a dark switch, the corresponding bit will turn into a 1. If you hold down the "reset" switch for that row and press a lighted switch, that bit will be reset to a 0. So, using that method you can enter an address and then modify the data or instruction at that address. The sense switches were a handy way to modify program execution. So, for example, if you had a GL transaction report that generated a detailed transaction report for the month plus subtotals and totals, you could signal the program to modify its operation using the sense switches. That way one program could generate a detail report for the month, a totals only report without detail, a daily report, or even an annual report with or without detail based on the sense switches that were active.
This machine looks like a fun find and I wish you luck restoring it. I only have one observation that I'll pass along, based on experience with other machines. Core memory uses a lot more power than one might expect and, often, that's why it ends up divided across multiple drawers with multiple power supplies.
Thanks for sharing and good luck. (Hope the back is better. )
Wow, wouldn't it be incredible to be able to get this machine and the Bendix to talk to each other !?!
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.
@@Jerrec oh yeah. That would be cool! Just making sure you knew he has some vids on the one he built👍
the way the central processor splits apart is extremeeeeely uncanny valley.
Happy New Year from Västervik, Sweden!
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 😁
Waving howdy from the general direction of Kerrville as I drive back to Houston.
On the label “MSC CALIB PROGRAM” the MSC stands for Manned Spacecraft Center which is the original name of what is now the Johnson Space Center. I recall as a young engineer in the late 1980s seeing an occasional MSC label here and there. Very cool!
Amazing what a bunch of common electrical components accomplished back than.
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!
This is the coolest thing I have ever seen!
That is a beauty.
I hope that you and your wife have a happy and productive new year
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.
Flap wheel rust remover. you can also get wire wheels that are sort of Brush/gap/Brush/gap etc , which aid with clogging avoidence
When you said rotating drum memory, I hit the like button. Yup.
The register buttons look like they work like the ones on the Univac 9400 mainframes I worked on many years ago: You press the Reset button to clear all the bits and then you press whichever buttons need to be set to a "1" state. When a bit is set, the light in that button turns on. If you press the wrong button, you have to reset everything and start over.
This video makes me sad. The largest of the Houston makerspaces, TX/RX, had probably thrown away more historical computing than it's preserved. I know that they had the training simulator for the CanadArm - they may still have the first handmade 6-axis controller that came with it, but the original 286 hardware and casing are long gone. Also gone is the Transmeta Crusoe cluster that noone was able to get functioning due to lost hard drives. It is good to see you preserving this historical computing hardware.
Nice work! I am sure Curios Marc will be watching,
I'll be looking forward to this project. I have a feeling that documentation will turn up. For those who are confused by "octal machine" it is a binary machine which is made easier to handle by grouping the bits into groups or three. Hexadecimal would group them by fours. Both are for the convenience of programmers. The machine itself is binary and couldn't care less how we read the core-dumps 😇
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
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.
All: "How many projects do you want to start?"
Usagi: 🐇