I cannot believe how incredibly well engineered this machine is considering how early in the computer age that it is from! Test points for everything, hackers already modifying hardware to make an input device to become a wide-carriage printer, etc. I am just loving this series when I really didn't think I would care that much at first. Thank you Dave and Lloyd for your time and effort in this, I am so invested now!
It's surprisingly well engineered! You can definitely tell that they meant for it to be repaired on site by technicians with minimal tools and repaired quickly. Once we overcame the terror of the rotating drum, things started falling into place rather quickly. Sure, there's going to be a ton of small faults and problems that slow us down along the way, but we're now getting into the things that are much easier to diagnose with a scope and some schematics. When I first talked with Bob about this machine, I said I was hoping to have it executing code and mostly running as expected by the end of 2024, and I think we're still definitely on track for that!
for us this was early in the computer age, for the original engineers they already had quite a few years of experience to get to this point. There were almost no "ordinary" users, people had to know their machine extremely well to operate them. I'm surprised Lloyd didn't tell whether he had encountered this kind of mods as he surely must've come across such practices. Onward to the next episode :)
Just a little suggestion from a long-time electrician/vintage electronics guy. Anytime there is aluminum used for electrical connections, make sure you put them together with antioxidant compound (we've always called it Noalox). This will prevent oxidation in the connections in the future and ensure you have solid contact. Any good hardware store should have it in the electrical section, and it is not expensive :) Anyway, I enjoyed the video as always! Keep up the good work!
@@TheGreatAtario It's not the same stuff, but it might work. The white compound we're speaking of is available in the electrical section of any hardware store I've seen in the US.
@@TheGreatAtario Deoxit does make some conductive greases that would work, but this is different from the liquid you are probably thinking of. There are aluminum specific products that I think would be better suited here for long term protection.
If I may be so bold, I suggest when this wonderful journey is done that you compile all the videos as one long watch. I think that would be epic to enjoy.
That would be a lot of hours, lol. But, if we go through and eliminate the intro and outro that are for bringing people up to speed on the previous episode, which could have been weeks or months prior normally, we could probably consolidate the entire thing down into a pretty concise two hour film. That could make for quite a good watch!
I'm sure you were already going to do so, but when you restore the typewriter please make sure to fully document the modifications that were made by the previous owner! I'd be very curious to see what changes they made to turn it into a glorified printer.
It is like watching "Who shot JR". I cannot wait to see this beastie, cough, cry and start to breathe again after being in techno-stasis for so long. Thanks for the perseverance!
As a freshman engineering student at UCLA, I worked with and programmed our Bendix G-15. Mostly it was because no one else wanted to use it, so I could have all the time I wanted. I have a pretty good guess why someone would convert this piece of junk into a printer. The vacuum tube logic was not reliable. I had to run my programs three times. If the answer agreed two out of three times, then I took it for correct. Sometimes the machine would not boot. Instead the paper tape reader would go crazy and wind off the end of the spool. This could also happen in the middle of program execution. There is no compiler and no assembler. All programs are written directly in G-15 machine code. Instead of binary, all arithmetic is done in the six decimal digits contained in a register. It is a fool's errand to attempt to program the G-15. The only logical thing to do with this machine is to turn it into a paper tape printer. Write a one line program that just reads the tape and prints it. I think that is probably what they did here.
Interesting input. What type of programs or calculations would one run on a machine like this? Like what would the operator be trying to accomplish? For example, what were you doing on the machine back then? Thanks
@@volvo09 It was the heyday of Robert McNamara and IEOR. We were supposed to put all our data into a simple linear model and use the computer to find the highest value of our "utility function". The numbers we put in were sheer guesswork, and the answer that came corresponded to our guesses. So my machine language program just multiplied each guess by a coefficient and then added it to a result. Easy program to write. As I said before, the machine often made mistakes, so I ran it multiple times until I had the same answer twice. Possibly the G-15 was not properly maintained. I was the only one using it, because I liked to work alone at night. Other students programmed in Fortran on the school's low-end IBM 360. That room had limited hours, and it was always crowded. I never had any problem with Fortran, but for a simple problem like this machine language was just as easy for me. From the looks of it, the machine you have was programmed to be a paper tape printer. That is the reason for the large platen on the modified typewriter. If someone else was paying for the electricity this would make some kind of sense, but it is really crude.
It would be fun to get your UE1 tube computer to feed in inputs to the G15’s tape reader so you could check the remainder of the boot process. That’s what they call, “system interoperability.” 😀 And you’d have a tale you could tell Bob at the System Source museum about how you used one tube computer to fix another tube computer! Epic! That’s gotta be worth at least a four bunny rating!
That would require some interesting level shifting boards between the two to isolate the expected voltage levels, but it would definitely be awesome to see the two tube computers playing nice with each other!
@@UsagiElectric I was thinking a small board with some white SMD LEDs on it and appropriate dropping resistors could be hooked to the UE1s output port, and the LEDs could be spaced to line up with the photodiodes in the tape reader. Then you wouldn’t need any level shifters between the two, nor even a common ground; total optical isolation. 😀
i bet that the type writer was modified to work as a printer for a different system! i bet they picked it up cheap somewhere, or maybe it was a left over after a company upgraded their systems.it has to have been done to save money, it really doesn't make sense other wise.
I was wondering whether they had it hooked in parallel with an unmodified typewriter, or maybe had an A/B switch configuration, so they could use the regular typewriter/terminal for interaction, while this one would just uncritically print everything the Bendix output.
"Slowly I turned... step by step... inch by inch!" Sometimes it's like that with old gear. Pretty bunny at the the end, man. You will figure this out, I'm sure.
@@horusfalcon Yeah - I was around 1 year old, and not (yet) into computers. That changed a bit over the years though. It really started for me when the SN7400 series where released (somewhere mid 1960's) and I started to build my own logic computing units (mind you, the first 4004 processor came a few years later). Good times...🙂
bunny nose wiggles thats the whole reason I'm here. the computer was fun to. lmao so close. I cant wait to see this thing alive and running code. really enjoying this series. thank you.
My theory is that that typewriter was not the only one used with that G15, there would have been another typewriter attached to a splitter that duplicated the cannon connectors so that way one typewriter would be the main terminal and the other (the one you have) would be a remote viewport to see what the G15 is doing in another room. That way you don't have to run all the way to the main terminal to check everything is still working. Certain lines on the second typewriter would be removed so the typewriter doesn't try to double any signals or power output (like the -20v line for example). All of this makes checking on a critical system that the G15 is running easier and faster to do. One thing I suspect is that the halt resistor was lifted to trouble shoot a different problem with the G15 and the people who were originally working on it did not finish and eventually forgot about it making it sit until you found it. Of course this is just a theory but I find it to be the most reasonable one I can think of that isn't something weird like the G15 being a demo machine because the functionality would be heavily altered along with the hardware if that were the case.
You're probably not to far off in your guess. They probably didn't want to change paper all the time when they wanted wide printouts, ao they would switch over to this printer. Printers were expensive and even IBM came up with a hack for their 1130 computer. They needed a printer for it and had a bunch of tabulating machines laying around. They pulled the printer assembly out and used the software in the computer to fire the hammers on the drum printer. The printer was slow but 80 lines a minute was better than nothing. They called it the 1132 printer but if you wanted something faster, the 1403 printer was a more costly options.
Hehe, must say that word "perseverance" always makes teenager inside of me chuckle a bit, because in Finnish the word "perse" means ass. 😂 Yeah, sorry about that. 😊
I have a theory that someone had the idea of modifying the typewriter because the computer would "only be for display" and "all you'll ever want to do with it is a short boot-up sequence just to demonstrate how it worked" instead of having it as a fully working computer which would actually be usable. So, they wired the typewriter up to be "The Bendix G-15 For Dummies" so that pressing any key would make it flash some lights to make it look impressive but nothing else.
a multi-million dollar (in today's money) machine invested in during the very beginning of the computer age....set aside for display only instead of doing work to justify it's expense?? I really don't think so bro.
@@exidy-ytI don't think the idea was that the original owner did that modification. I could absolutely see someone in like the 1970s or 1980s doing that though, at a time when this hardware was clearly obsolete and not actually being used for work anymore.
@@exidy-ytcopy function for audit trail, though carbon paper could have been used. I have a juki2200 typewriter with parallel interface that is an output only machine unfortunately
Display only might work if it's a critical system and it's only running from tape with a printout of any calculations. Maybe they just botched the mod or are controlling some things externally?
@@exidy-ytIf they have that much money to blow, they probably bought multiple typewriters to do the actual work. It could be eye candy for a dumb CEO or executive to ogle at like a baby in order to justify the expense of the fancy new machine. "Ooohhhh pretty blinky lights!!! Your project is approved!!!", while drooling. Either that, or in the same vein, it's modified with a boss-lock/general-lock (For military.) so that the moron doesn't break anything because he knows better than the engineers.
The last time I wanted so much to watch the rest of the repair process was when CuriousMarc & team were restoring the Xerox Alto. You are doing an incredible job. I can't wait to see this machine running code again.
This G15 restoration is a rollercoaster! Can't believe the amount of weird mods you're uncovering. That typewriter is definitely giving you a run for your money! Keep up the great work, can't wait to see that first boot-up!
Yup, that's the biggest mystery of the whole machine. The previous owner (before Bob at System Source) of the machine had three other G15s and about 10 typewriters. Throughout the years the typewriters got misplaced and moved about, so this typewriter is most assuredly not the typewriter that originally came with the system. We'll figure it out though!
At least that chassis isn't cadmium plated. I've had to deal with cadmium sulphide corrosion in the past (that's the yellow stuff which shows up on old cadmium plating).
"And I didn't have any idea what to do but I knew I needed a click. So, we put a click on the 24-track which then was synced to the Moog modular. I knew that it could be a sound of the future but I didn't realize how much the impact would be."
Your excitement and enthusiasm for this makes for an epic video to watch - looks like you are soooooo close to getting it up and running, have watched this whole series with interest.
at 4:07 you can see writing on the side of the printer bottom that appears to say "Output Typewr" so output typewriter, so your assumption that it is a glorified printer is likely correct at least at some point in its life. I would assume whoever used the g15 needed to print out either portions of the programs memory or data to help them troubleshoot something, before trusting it to run properly. When I was in CS classes, we would sometimes test programs that would show errors but wouldn't necessarily show in the debugger by just forcing the program to print out each steps data so we could check. I know Luke Talley, the docent at the Saturn 5 rocket museum and also helped build the systems to control the rocket's flight in the 60's talked about printing out giant sheets of octal data that ran down the hallways and they would comb over it to fix errors.
I started working with electronics and computers back in the mid 70s and I don't think I've seen a circuit board more rough looking than in that teleprinter unit! If anyone can fix it, it's Dave!!
Just love the way you debug everything. You should be so proud of you accomplishments. So well done. I am excited with where this is going all the best from across the pond.
“Marvin trudged on down the corridor, still moaning. "...and then of course I've got this terrible pain in all the diodes down my left hand side..." "No?" said Arthur grimly as he walked along beside him. "Really?" "Oh yes," said Marvin, "I mean I've asked for them to be replaced but no one ever listens." "I can imagine.”
So awesome! Watched the whole series. I feel your joy, it is that you live so far away, otherwise I would come over to assist in troubleshooting. I love these challenges!
I'm still unsure quite what to expect when this thing actually boots, but I can't wait to see it. Knowing your community, it will probably wind up with a full blown emulator available online and a fully reverse engineered instruction set. Your videos in general since I started watching you (quite early on in your channel) just keep getting better and better, in every aspect. I feel like I'm sitting next to you while you debug this stuff. Your excitement is infectious.
Upside down solder repairs without getting splattered... my man! I got a reel to reel that's moving slow be interesting to see what you are dealing with maybe get me started in the right direction.
I've got a crazy idea for an application program for the Bendix, once you get it rolling. How about some character art, read from a paper tape, scaled and printed on ANSI D-size paper (22" x 34"), which will fit just fine in that MASSIVE 28" platen. Great project. I've been following this since the beginning.
Sorry, but it's called a carriage. The platen is the rubber covered roller the paper wraps around. These wide-carriage printers were extremely common in computers and accounting machines early on, as they could accomodate full size general ledger pages. Cheers, Dave
Where do you get 28 inch paper 😮? I realize that the typewriter could use up to 28 inch paper, but that meant somewhere along the line someone was making 28 inch paper? Also that's not a pin feed printer so keeping the paper straight coming from what I would assume was a roll at that time not fanfold like we're used to seeing with the pin feed paper would have been a chore.
@@GothGuy885 I use 13x19 inch paper in my Epson printer. There is some stuff that just looks better on bigger paper. As people figure out that I have the printer, I get requests to do special jobs. Other times, I do one printout for the office and visitors want copies of the printout. People are finding out they can't live without my printer.
oooooooooooooooh so much progress!!!!!!! It's awesome to see Mr Lloyd tagging along for the ride! Game of Thrones who? Give me fridge sized computer sagas any day!
I felt so silly spending half a day fixing the motor on my 1973 tape deck - when it turned out to be the motor caps that were out of spec. Remember to check those first, like I didn’t :)
I swear this is like Sarah n' tuned's 74 Celica restomod. It just inches along, closer and closer to completion... I love both even though they're in totally different areas of interest.
That's encouraging progress! Great to see :) Looks like you'll be busy between episodes (1) refurbing the running gear for the punch-tape reader; (2) documenting the mods and then "un-bodging" the TTY As always with this G15, nice to see Lloyd on-hand to lend his expertise and experience 👍
Congrats... Each video is progress. I hear you when you say that just trying to hack the one item to get it to boot is more work than just facing the problem with that typewriter head on. I don't know why they would modify it such, maybe to prevent operator error and to lock out use of the system to only allow a limited number of operations? I think that is essential what you were thinking too.
Fascinating project! But it does look as though someone used a poker for a soldering iron. I can't imagine someone being satisfied with such a bodge as on that typewriter. Perhaps it was just an experiment?
@@MrLampbus 🤣 In fact soldering some things like that is fine. I really think electronic wiring deserves something more appropriate! If it didn't, this wiring wouldn't _look_ as though it had been soldered with a poker...
If the LCM were doing this they would probably have built an emulator for the console typewriter...but then they had a ton more money (and I mean a ton).
I had a feeling those typewriter PCB mods would bite you like fox after a rabbit. You have gone far enough now to knuckle down and restore that PCB. Tape motor: ten to one the bearings are dry.
Hopefully it's not the type of motor with permanent magnets inside. I've had issues repairing jukeboxes from the same era as the Bendix, where the magnets in the motors had weakened over the decades. Only fix was to replace the motor.
I wonder if that printer was a second printer for the machine and that's why all of the boot logic bits were disabled in it? Maybe its only job was to write out a copy of whatever was going on for archiving purposes. Maybe someone just leaves a weight on the A key when they want it to run.
I think it was mentioned Loyd's machine isn't running as well. I'm not sure about that, though. But yea, a functioning typewriter might be helpful in troubleshooting or rebuilding its original state.
I noticed that some of the paper capacitors in the power supply of the typewriter look a little burned. You may want to change them, and check the ones in the tape drive too. Sometimes leaky capacitors can cause things not to work properly.
wait wait, they used a steel sheet an coupled it to an aluminium rod and passed electricity through them? Inst' that like, textbook galvanic corrosion?
It's a shame the typewriter was modified that heavily. I can only guess they really wanted to make sure that only printing was possible. On the other hand - even removing the other keys to prevent someone from pressing them would have been an easier modification than soldering everything together....
And the soldering looks utterly appalling, either because the person who did it wasn't great at soldering or because the wires were already badly corroded when the mod was done.
seems to me like someone was in the middle of trying to troubleshoot a problem, and they had to stop for whatever reason, and never got back around to finishing fixing the issue, and then however many decades later, the issue is now yours to fix
that instruction set is super weird, almost like ARM where the entire instruction 'word' manhandles the entire machine... or at least thats all i could deduce from the docs on bitsavers, tried writing fizzbuzz but to no avail, let alone who has made an emulator for such an old machine to test new software!
Are there any other Bendix typewriters still in existence, with the standard platen (versus this 'crazy pants' one)? If so, what about arranging for some detail closeups of the wiring? That would probably help with figuring out this puzzle.
No chance of a stock simple console, huh. It's gotta be the one that runs output. CHAGRIN. Also, should the lamps in the reader be THAT effing bright? And yes, the old guy (me) was born before the G15 came out.
I’ll be honest, I dozed off for a few minutes, and when I opened one eye just before the initial boot, I wasn’t 100% sure anyone else could see that other fella.
cool I admire you super and in general I congratulate you simply super work a lot of work is devoted here and beautifully restored machine it is simply beautiful 👍
I sincerely can´t wait for this to finally do the Thing! Walk The Walk, Buzz the Buzz! You can do it, don´t care for the why- just accept it and move on. But: all that old solder needs to go (I think) and be replaced with fresh lead solder. Yeah, the old stuff might work after reflow but I go the extra mile and put new in my old stuff. With a 12v fan&duct to carry the fumes away. But to prove a point just put it back and (I hope) there we go. Kind Regards & no magic smoke...
![Eminem - Like My Shit [Official Audio]](http://i.ytimg.com/vi/vx_IMvFkrfA/mqdefault.jpg)
A hardware implementation of "Press any key to continue".
I could never find the "Any" key.
There's a lot of mysteries hiding out in that typewriter, but we'll get it acting right before too long.
@@AndrewTubbiolo I want a custom keyboard with an Any key where the windows key usually is
@@awesomecronk7183 Great idea! Me and my 3d printer will make one!
@@UsagiElectricI wonder if it was used as an additional printer.
I cannot believe how incredibly well engineered this machine is considering how early in the computer age that it is from! Test points for everything, hackers already modifying hardware to make an input device to become a wide-carriage printer, etc. I am just loving this series when I really didn't think I would care that much at first. Thank you Dave and Lloyd for your time and effort in this, I am so invested now!
This is the most bonkers, insane computer I have ever seen; I love it! Can't wait to see the tape drive spinning as it should!
It's surprisingly well engineered!
You can definitely tell that they meant for it to be repaired on site by technicians with minimal tools and repaired quickly. Once we overcame the terror of the rotating drum, things started falling into place rather quickly. Sure, there's going to be a ton of small faults and problems that slow us down along the way, but we're now getting into the things that are much easier to diagnose with a scope and some schematics.
When I first talked with Bob about this machine, I said I was hoping to have it executing code and mostly running as expected by the end of 2024, and I think we're still definitely on track for that!
for us this was early in the computer age, for the original engineers they already had quite a few years of experience to get to this point. There were almost no "ordinary" users, people had to know their machine extremely well to operate them. I'm surprised Lloyd didn't tell whether he had encountered this kind of mods as he surely must've come across such practices.
Onward to the next episode :)
Expensive technology is usually well engineered. It's worth the extra R&D money, and the minimal downtime is a great selling point.
Giving a whole new meaning to "Press A key to continue" :-D
Any is just A key, lol!
Just a little suggestion from a long-time electrician/vintage electronics guy. Anytime there is aluminum used for electrical connections, make sure you put them together with antioxidant compound (we've always called it Noalox). This will prevent oxidation in the connections in the future and ensure you have solid contact. Any good hardware store should have it in the electrical section, and it is not expensive :)
Anyway, I enjoyed the video as always! Keep up the good work!
Yep. It's also used on large aluminum wire terminating in high-current breaker boxes.
Would Deoxit also work?
@@TheGreatAtario It's not the same stuff, but it might work. The white compound we're speaking of is available in the electrical section of any hardware store I've seen in the US.
@@TheGreatAtario Deoxit does make some conductive greases that would work, but this is different from the liquid you are probably thinking of. There are aluminum specific products that I think would be better suited here for long term protection.
If I may be so bold, I suggest when this wonderful journey is done that you compile all the videos as one long watch.
I think that would be epic to enjoy.
That can be done with a playlist, takes a few minutes to set it up.
That would be a lot of hours, lol.
But, if we go through and eliminate the intro and outro that are for bringing people up to speed on the previous episode, which could have been weeks or months prior normally, we could probably consolidate the entire thing down into a pretty concise two hour film. That could make for quite a good watch!
@@UsagiElectric I'm sure you could cross the 3 hour mark and most of us would still watch
I'm sure you were already going to do so, but when you restore the typewriter please make sure to fully document the modifications that were made by the previous owner! I'd be very curious to see what changes they made to turn it into a glorified printer.
I thought the same. It might be a project saver for somebody down the road.
It is like watching "Who shot JR". I cannot wait to see this beastie, cough, cry and start to breathe again after being in techno-stasis for so long. Thanks for the perseverance!
Thanks for hanging with us as we go through bringing it up!
It's an honor to work on such a rare and unique machine!
The scope has more computing power in it than a whole room full of G15s! I love the Bendix, it looks so awesome, don't stop!
As a freshman engineering student at UCLA, I worked with and programmed our Bendix G-15. Mostly it was because no one else wanted to use it, so I could have all the time I wanted. I have a pretty good guess why someone would convert this piece of junk into a printer.
The vacuum tube logic was not reliable. I had to run my programs three times. If the answer agreed two out of three times, then I took it for correct. Sometimes the machine would not boot. Instead the paper tape reader would go crazy and wind off the end of the spool. This could also happen in the middle of program execution.
There is no compiler and no assembler. All programs are written directly in G-15 machine code. Instead of binary, all arithmetic is done in the six decimal digits contained in a register. It is a fool's errand to attempt to program the G-15.
The only logical thing to do with this machine is to turn it into a paper tape printer. Write a one line program that just reads the tape and prints it. I think that is probably what they did here.
Interesting input.
What type of programs or calculations would one run on a machine like this? Like what would the operator be trying to accomplish? For example, what were you doing on the machine back then?
Thanks
@@volvo09 It was the heyday of Robert McNamara and IEOR. We were supposed to put all our data into a simple linear model and use the computer to find the highest value of our "utility function". The numbers we put in were sheer guesswork, and the answer that came corresponded to our guesses. So my machine language program just multiplied each guess by a coefficient and then added it to a result. Easy program to write. As I said before, the machine often made mistakes, so I ran it multiple times until I had the same answer twice. Possibly the G-15 was not properly maintained. I was the only one using it, because I liked to work alone at night. Other students programmed in Fortran on the school's low-end IBM 360. That room had limited hours, and it was always crowded. I never had any problem with Fortran, but for a simple problem like this machine language was just as easy for me.
From the looks of it, the machine you have was programmed to be a paper tape printer. That is the reason for the large platen on the modified typewriter. If someone else was paying for the electricity this would make some kind of sense, but it is really crude.
It would be fun to get your UE1 tube computer to feed in inputs to the G15’s tape reader so you could check the remainder of the boot process. That’s what they call, “system interoperability.” 😀 And you’d have a tale you could tell Bob at the System Source museum about how you used one tube computer to fix another tube computer! Epic! That’s gotta be worth at least a four bunny rating!
That would be insane and awesome!
That would require some interesting level shifting boards between the two to isolate the expected voltage levels, but it would definitely be awesome to see the two tube computers playing nice with each other!
@@UsagiElectric I was thinking a small board with some white SMD LEDs on it and appropriate dropping resistors could be hooked to the UE1s output port, and the LEDs could be spaced to line up with the photodiodes in the tape reader. Then you wouldn’t need any level shifters between the two, nor even a common ground; total optical isolation. 😀
it's really amazing that hardware that old can be brought back to life (sort of)!
Everything on this thing was built to last for sure, it's a beast and so far, we've come across surprisingly few bad components!
Nice to see Lloyd again!
i bet that the type writer was modified to work as a printer for a different system! i bet they picked it up cheap somewhere, or maybe it was a left over after a company upgraded their systems.it has to have been done to save money, it really doesn't make sense other wise.
I was wondering whether they had it hooked in parallel with an unmodified typewriter, or maybe had an A/B switch configuration, so they could use the regular typewriter/terminal for interaction, while this one would just uncritically print everything the Bendix output.
"Slowly I turned... step by step... inch by inch!" Sometimes it's like that with old gear. Pretty bunny at the the end, man.
You will figure this out, I'm sure.
NIAGARA FALLS!
@@loginregional Yeah. Glad to see a fan of the classics out there (Larry, Moe, and Curly ain't got nothin' on me!) 😆
We're getting there!
We definitely will not quit until this thing is purring along like it did when it was new in 1956!
@@UsagiElectric _Hey._ I was new in 1956! 😆
@@horusfalcon Yeah - I was around 1 year old, and not (yet) into computers. That changed a bit over the years though. It really started for me when the SN7400 series where released (somewhere mid 1960's) and I started to build my own logic computing units (mind you, the first 4004 processor came a few years later). Good times...🙂
bunny nose wiggles thats the whole reason I'm here. the computer was fun to. lmao
so close. I cant wait to see this thing alive and running code. really enjoying this series. thank you.
Fantastic to see this behemoth coming back from the grave. Don't quit!
Definitely not, we won't consider our job done until this thing is humming along like it did when it was new in 1956!
I'm amazed that 70 year old board doesn't completely short out, or completely go open circuit. It seems to be more dust than parts.
It really does need a huge cleaning!
My theory is that that typewriter was not the only one used with that G15, there would have been another typewriter attached to a splitter that duplicated the cannon connectors so that way one typewriter would be the main terminal and the other (the one you have) would be a remote viewport to see what the G15 is doing in another room. That way you don't have to run all the way to the main terminal to check everything is still working. Certain lines on the second typewriter would be removed so the typewriter doesn't try to double any signals or power output (like the -20v line for example). All of this makes checking on a critical system that the G15 is running easier and faster to do. One thing I suspect is that the halt resistor was lifted to trouble shoot a different problem with the G15 and the people who were originally working on it did not finish and eventually forgot about it making it sit until you found it. Of course this is just a theory but I find it to be the most reasonable one I can think of that isn't something weird like the G15 being a demo machine because the functionality would be heavily altered along with the hardware if that were the case.
You're probably not to far off in your guess. They probably didn't want to change paper all the time when they wanted wide printouts, ao they would switch over to this printer. Printers were expensive and even IBM came up with a hack for their 1130 computer. They needed a printer for it and had a bunch of tabulating machines laying around. They pulled the printer assembly out and used the software in the computer to fire the hammers on the drum printer. The printer was slow but 80 lines a minute was better than nothing. They called it the 1132 printer but if you wanted something faster, the 1403 printer was a more costly options.
Congratulations, those are huge steps forward. Thank you for having the perseverance to preserve this bit of history.
Hehe, must say that word "perseverance" always makes teenager inside of me chuckle a bit, because in Finnish the word "perse" means ass. 😂
Yeah, sorry about that. 😊
@@Helltormentor I’m always in favor of expanding the vocabulary. Thanks for the reply. Thumbs up.
Slowly but surely we're getting there!
@@wtmayhew If you want to know some more "dirty" words in Finnish, I'll be glad to help. :)
@@UsagiElectric What a journey this has been so far...
I have a theory that someone had the idea of modifying the typewriter because the computer would "only be for display" and "all you'll ever want to do with it is a short boot-up sequence just to demonstrate how it worked" instead of having it as a fully working computer which would actually be usable. So, they wired the typewriter up to be "The Bendix G-15 For Dummies" so that pressing any key would make it flash some lights to make it look impressive but nothing else.
a multi-million dollar (in today's money) machine invested in during the very beginning of the computer age....set aside for display only instead of doing work to justify it's expense?? I really don't think so bro.
@@exidy-ytI don't think the idea was that the original owner did that modification. I could absolutely see someone in like the 1970s or 1980s doing that though, at a time when this hardware was clearly obsolete and not actually being used for work anymore.
@@exidy-ytcopy function for audit trail, though carbon paper could have been used. I have a juki2200 typewriter with parallel interface that is an output only machine unfortunately
Display only might work if it's a critical system and it's only running from tape with a printout of any calculations. Maybe they just botched the mod or are controlling some things externally?
@@exidy-ytIf they have that much money to blow, they probably bought multiple typewriters to do the actual work.
It could be eye candy for a dumb CEO or executive to ogle at like a baby in order to justify the expense of the fancy new machine. "Ooohhhh pretty blinky lights!!! Your project is approved!!!", while drooling.
Either that, or in the same vein, it's modified with a boss-lock/general-lock (For military.) so that the moron doesn't break anything because he knows better than the engineers.
I love this Bendix project so much ❤🌷
The last time I wanted so much to watch the rest of the repair process was when CuriousMarc & team were restoring the Xerox Alto. You are doing an incredible job. I can't wait to see this machine running code again.
This G15 restoration is a rollercoaster! Can't believe the amount of weird mods you're uncovering. That typewriter is definitely giving you a run for your money! Keep up the great work, can't wait to see that first boot-up!
That typewriter is in a right state.
Yup, that's the biggest mystery of the whole machine. The previous owner (before Bob at System Source) of the machine had three other G15s and about 10 typewriters. Throughout the years the typewriters got misplaced and moved about, so this typewriter is most assuredly not the typewriter that originally came with the system. We'll figure it out though!
@@UsagiElectric It's all part of the fun.
At least that chassis isn't cadmium plated. I've had to deal with cadmium sulphide corrosion in the past (that's the yellow stuff which shows up on old cadmium plating).
"And I didn't have any idea what to do but I knew I needed a click. So, we put a click on the 24-track which then was synced to the Moog modular. I knew that it could be a sound of the future but I didn't realize how much the impact would be."
My name is Giovanni Giorgio.
but everybody calls me *Giorgio.*
@@themac6356 I would like your comment, but that would screw up the order.
Your excitement and enthusiasm for this makes for an epic video to watch - looks like you are soooooo close to getting it up and running, have watched this whole series with interest.
I'm totally new to old computers, and it's exciting to see vacuum tubes in action! So cool.
Your tenacity is inspiring.
at 4:07 you can see writing on the side of the printer bottom that appears to say "Output Typewr" so output typewriter, so your assumption that it is a glorified printer is likely correct at least at some point in its life. I would assume whoever used the g15 needed to print out either portions of the programs memory or data to help them troubleshoot something, before trusting it to run properly. When I was in CS classes, we would sometimes test programs that would show errors but wouldn't necessarily show in the debugger by just forcing the program to print out each steps data so we could check. I know Luke Talley, the docent at the Saturn 5 rocket museum and also helped build the systems to control the rocket's flight in the 60's talked about printing out giant sheets of octal data that ran down the hallways and they would comb over it to fix errors.
"a couple of problems" ---> "... a boat load of problems" :P
*aaaaaaaaaaaaaaaaaaa*
The typewriter is voicing it's opinion on the modifications done to it.
I hope, this project will take much much longer, because I would be feel very sad, if this beautiful machine is gone one day.
someone achieved "press any key to continue" in hardware rather than software lol
I started working with electronics and computers back in the mid 70s and I don't think I've seen a circuit board more rough looking than in that teleprinter unit! If anyone can fix it, it's Dave!!
Just love the way you debug everything. You should be so proud of you accomplishments. So well done. I am excited with where this is going all the best from across the pond.
This is so nerve wracking, hoping it to work, hoping no smoke comes out, top notch content 😂
“Marvin trudged on down the corridor, still moaning. "...and then of course I've got this terrible pain in all the diodes down my left hand side..."
"No?" said Arthur grimly as he walked along beside him. "Really?"
"Oh yes," said Marvin, "I mean I've asked for them to be replaced but no one ever listens."
"I can imagine.”
Which book is that?
Book 1 of the increasingly inaccurately named trilogy The Hitchhikers Guide to the Universe by Douglas Adams
@@droningof course was rendered best in the original radio series
So awesome! Watched the whole series. I feel your joy, it is that you live so far away, otherwise I would come over to assist in troubleshooting. I love these challenges!
I do like that the graphic of 'everything is connected to A' is on page 42 of the schematics.
Been following this from day 1 ... that was super exciting seeing the paper tape reader move!
This is one of the most epic story archs of our time
I'm still unsure quite what to expect when this thing actually boots, but I can't wait to see it. Knowing your community, it will probably wind up with a full blown emulator available online and a fully reverse engineered instruction set.
Your videos in general since I started watching you (quite early on in your channel) just keep getting better and better, in every aspect. I feel like I'm sitting next to you while you debug this stuff. Your excitement is infectious.
Man, great to see this thing slowly coming to life, one signal at a time!
Upside down solder repairs without getting splattered... my man! I got a reel to reel that's moving slow be interesting to see what you are dealing with maybe get me started in the right direction.
Fantastic progress! Maybe add a detachable panel that displays the state(s) so you can see what it is doing. Adding blinking lights is a good thing.
Aw man, so worth it for the bun at the end.
Comment for engagement: This is the most exciting series on RUclips at the moment!
It is neck-and-neck with CuriousMarc's Apollp series. And when they appear together, wow!
the bunny at the end fills my soul
I can't wait for this thing to be operational! What a cool machine!
I've got a crazy idea for an application program for the Bendix, once you get it rolling.
How about some character art, read from a paper tape, scaled and printed on ANSI D-size paper (22" x 34"), which will fit just fine in that MASSIVE 28" platen.
Great project. I've been following this since the beginning.
Sorry, but it's called a carriage. The platen is the rubber covered roller the paper wraps around.
These wide-carriage printers were extremely common in computers and accounting machines early on, as they could accomodate full size general ledger pages.
Cheers,
Dave
Correct, though carriage length and platen length go hand-in-hand.
Lifted resistors in the typewriter may be from a previous person disconnecting them while troubleshooting.
Guys who need a 28" platen are compensating for something.
Where do you get 28 inch paper 😮? I realize that the typewriter could use up to 28 inch paper, but that meant somewhere along the line someone was making 28 inch paper?
Also that's not a pin feed printer so keeping the paper straight coming from what I would assume was a roll at that time not fanfold like we're used to seeing with the pin feed paper would have been a chore.
as my friend used to say " 28''' ? that's not a measurement, that's an address!"
Time to buy a Corvette….
@@GothGuy885 I use 13x19 inch paper in my Epson printer. There is some stuff that just looks better on bigger paper. As people figure out that I have the printer, I get requests to do special jobs. Other times, I do one printout for the office and visitors want copies of the printout. People are finding out they can't live without my printer.
Amazing video. Almost as fun as the Centurion.
Just wait until he starts writing custom paper tape code for the Bendix ;D
hellorld in bendix paper tape
@@aelitadelarobia😂😂😂 yesssss!
oooooooooooooooh so much progress!!!!!!! It's awesome to see Mr Lloyd tagging along for the ride!
Game of Thrones who? Give me fridge sized computer sagas any day!
The typewriter-and its modifications-are fascinating. I like to think it served as a wide screen monitor for the day.
I have one of the first DSOs that uses 7x logic, it came from a guy who worked for DEC and would be interesting to use in your troubleshooting
The fact that she woke at all and is trying her best says enough!
It's great to see this machine being resurrected!
What a beast 😂
Love these machines. Good luck !
10:54 "Lloyd, would you like to do the honors?"
"BLERGH!"
I felt so silly spending half a day fixing the motor on my 1973 tape deck - when it turned out to be the motor caps that were out of spec. Remember to check those first, like I didn’t :)
I love how the tape reader on the Bendix looks like the coin slots on an old pinball machine. "Insert 50¢ to initiate boot sequence"
I swear this is like Sarah n' tuned's 74 Celica restomod. It just inches along, closer and closer to completion... I love both even though they're in totally different areas of interest.
That's encouraging progress! Great to see :) Looks like you'll be busy between episodes (1) refurbing the running gear for the punch-tape reader; (2) documenting the mods and then "un-bodging" the TTY
As always with this G15, nice to see Lloyd on-hand to lend his expertise and experience 👍
I'm glad you are a fan of old computers.......... it's your motivation to keep going. Best wishes on the journey.
Nice to see the progress!
thats so awesome, keep up the good work!
Congrats... Each video is progress. I hear you when you say that just trying to hack the one item to get it to boot is more work than just facing the problem with that typewriter head on. I don't know why they would modify it such, maybe to prevent operator error and to lock out use of the system to only allow a limited number of operations? I think that is essential what you were thinking too.
I like the old school optical storage.
Great job as always! It’s fun to watch you bring back an old computer to life…..😄
Fascinating project! But it does look as though someone used a poker for a soldering iron. I can't imagine someone being satisfied with such a bodge as on that typewriter. Perhaps it was just an experiment?
I worked on an art project with a blacksmith...he always soldered wiring with a large square poker thing that he heated in his forge.
@@MrLampbus 🤣 In fact soldering some things like that is fine. I really think electronic wiring deserves something more appropriate! If it didn't, this wiring wouldn't _look_ as though it had been soldered with a poker...
It kind of feels like in the spirit of Curious Marc it would be good to make a circuit board that emulates the keyboard/typewriter.
Im exited to see this run!
If the LCM were doing this they would probably have built an emulator for the console typewriter...but then they had a ton more money (and I mean a ton).
I had a feeling those typewriter PCB mods would bite you like fox after a rabbit. You have gone far enough now to knuckle down and restore that PCB. Tape motor: ten to one the bearings are dry.
Hopefully it's not the type of motor with permanent magnets inside. I've had issues repairing jukeboxes from the same era as the Bendix, where the magnets in the motors had weakened over the decades. Only fix was to replace the motor.
@@djsherz there ARE ways to remagnetize them but it isnt easy
@@SlavTiger Beyond my skill set anyway haha.
I wonder if that printer was a second printer for the machine and that's why all of the boot logic bits were disabled in it? Maybe its only job was to write out a copy of whatever was going on for archiving purposes. Maybe someone just leaves a weight on the A key when they want it to run.
If Loyd has a G15 why not bring his typewriter?
I think it was mentioned Loyd's machine isn't running as well. I'm not sure about that, though. But yea, a functioning typewriter might be helpful in troubleshooting or rebuilding its original state.
Guys! World is watching. Finger crossed.
I noticed that some of the paper capacitors in the power supply of the typewriter look a little burned. You may want to change them, and check the ones in the tape drive too. Sometimes leaky capacitors can cause things not to work properly.
wait wait, they used a steel sheet an coupled it to an aluminium rod and passed electricity through them? Inst' that like, textbook galvanic corrosion?
It's a shame the typewriter was modified that heavily. I can only guess they really wanted to make sure that only printing was possible. On the other hand - even removing the other keys to prevent someone from pressing them would have been an easier modification than soldering everything together....
And the soldering looks utterly appalling, either because the person who did it wasn't great at soldering or because the wires were already badly corroded when the mod was done.
Keep on it. Love to see this relic reanimated.
My hero!
Please, get 4K cameras, all of these videos and details must be recorded in ultra high definition for the posterity.
I wonder what the Bendix engineers would have made of that scope ..
Did you ever do an episode on your pinballs ?
There was a general overview around Christmas 2023 of the stuff in the room
seems to me like someone was in the middle of trying to troubleshoot a problem, and they had to stop for whatever reason, and never got back around to finishing fixing the issue, and then however many decades later, the issue is now yours to fix
that instruction set is super weird, almost like ARM where the entire instruction 'word' manhandles the entire machine... or at least thats all i could deduce from the docs on bitsavers, tried writing fizzbuzz but to no avail, let alone who has made an emulator for such an old machine to test new software!
On Zero Volts B, the 3.3ohms is probably the DC resistance of that inductor there.
Are there any other Bendix typewriters still in existence, with the standard platen (versus this 'crazy pants' one)? If so, what about arranging for some detail closeups of the wiring? That would probably help with figuring out this puzzle.
Awesome!
No chance of a stock simple console, huh. It's gotta be the one that runs output. CHAGRIN. Also, should the lamps in the reader be THAT effing bright? And yes, the old guy (me) was born before the G15 came out.
They make AL anti oxidant stuff at the big box stores. it helps both AL and copper connections.
I’ll be honest, I dozed off for a few minutes, and when I opened one eye just before the initial boot, I wasn’t 100% sure anyone else could see that other fella.
When the re-set button meant it actually had to RE set its position. :))
this is cool. i have forgotten more electronics than I remember.
Whenever he does the startup process I think of The Count from Sesame Street. One click, hahahaha!, Two, Two clicks, hahaha!
cool I admire you super and in general I congratulate you simply super work a lot of work is devoted here and beautifully restored machine it is simply beautiful 👍
Neat stuff, thanks for sharing.
I sincerely can´t wait for this to finally do the Thing! Walk The Walk, Buzz the Buzz!
You can do it, don´t care for the why- just accept it and move on. But: all that old solder needs to go (I think) and be replaced with fresh lead solder. Yeah, the old stuff might work after reflow but I go the extra mile and put new in my old stuff. With a 12v fan&duct to carry the fumes away.
But to prove a point just put it back and (I hope) there we go. Kind Regards & no magic smoke...