The Bendix G15 (Almost) Roars into Life!

This is the big one - we push that tantalizing green button to fully bring up DC and get the machine online! Of course, things don’t quite go as planned, and we didn’t get as far as we had hoped. But, lots of exciting things happened and the machine is in a very good state to be brought up fully and executing code soon!
Check out System Source here:
museum.syssrc.com/
If you want to support the channel please hop over to Patreon:
/ usagielectric
Also, we now have some epic shirts for sale!
my-store-11554688.creator-spr...
Come join us on Discord!
Discord: / discord
Intro Music adapted from:
Artist: The Runaway Five
Title: The Shinra Shuffle
ocremix.org/remix/OCR01847
Thanks for watching!
Chapters
0:00 Who let me get my hands on a piece of history?
1:24 Why has it been so long since the last episode?
3:15 A little bit of capacitor checking
5:48 Pushing the green button!
7:44 Hmm, that’s not great…
10:32 Pushing the green button again!
12:14 Why won’t it start up fully?
18:54 She wants to run though!
23:14 Baby bunny!

[@dodgem259]

Having a Bendix repair tech who repaired those machines in the 70's living 2 hrs away is like winning the lottery.

[@donsurlylyte]

esp in tx, where it can be a 2 hr drive to the mall.

[@simonstergaard]

We want an interview about his professional life on this machine....pleeeeease

[@mikepartin571]

@@simonstergaard omg yes, that would be legendary

[@UsagiElectric]

It was crazy lucky that we are so close to each other, and you're right, the closest mall to me is 1.25 hours away, haha.

[@dasiro]

So basically your next-next-door neighbor is coincidentally probably one of the only few people alive who has years of professional experience with these and could still repair this ancient marvel of technology. I'm glad this restoration isn't over yet and we can look forward to yet at least one other episode

[@CTRIX64]

I'm so glad you waited until Lloyd was present to fire up the G15. Watching him wonder over within seconds (having noticed which parts had come to life) and instinctively start debugging, checking calibration, pointing out missing lights in the init sequence - how lucky we are to have a Bendix tech on board. Thanks Lloyd! Great to see you back on your feet

[@jeromethiel4323]

Need to preserve that knowledge while he's still alive.

[@UsagiElectric]

Having Lloyd there, helping guide us in the right direction has been absolutely amazing!

[@nysaea]

Man, Mr Lloyd just casually turning knobs like it's second nature really stole the show there! What a team!

[@UsagiElectric]

I had to tell Lloyd to wait a second while I pulled out a camera to get that shot, haha.

[@jasonhaman4670]

@@UsagiElectric Glad you did! You're preserving this for posterity.

[@OscarSommerbo]

Big shout out and thanks to Lloyd!

[@UsagiElectric]

Lloyd is the man!

[@spacewolfjr]

Merry Lloyd-mass to everyone! I was so sad when I heard he got bit by a bird (on the foot) but I'm so thankful he has recovered 🙏

[@CuriousMarc]

Woohoo, you got memory! Congrats! She definitely wants to run.

[@ml.2770]

Lloyd worked, repaired and programmed G15s in the 70s and lives 2 hours away?! That's about as probable as restoring a completely undocumented machine and finding all the engineering documents about that machine in the unused space between partitions on the hard drive .

[@TheRetroBristolian]

Ha... there's no way that anyone would be that lucky to find all the documents of an undocumented machine in such an unlikely scenario.... no one is THAT lucky.... 😅 - from a fellow ADB viewer!

[@timradde4328]

That's just about what happened with Adrian Black (Adrian's Digital Basement). He has a Plexus P-20. And they did indeed find all the engineering documents on a different partition. I may not be quite right but there is little on the Internet about the P-20. So he was incredibly lucky. Cool machine too. I had never heard of it.

[@TheRetroBristolian]

@@timradde4328 I know.... that's why I said a fellow ADB viewer - Adrian's Digital Basement) :-) absolutely an incredible story and bit of luck.

[@timradde4328]

@@TheRetroBristolian Sorry, I must have missed that last part by not clicking the "more". I just thought to myself this sounds familiar. Again, sorry.

[@TheRetroBristolian]

@@timradde4328 all good! no harm done :-) It's just so good to see so many like minded people enjoying, learning and sharing about this old tech. It's just a great, friendly community where everyone is just so positive and willing to share and help.

[@malcolmgibson6288]

I love the way Lloyd is so laid back about having one in his garage.

[@WillowEpp]

I caught that, too! Extremely powerful computer history humblebrag. (⁠≧⁠▽⁠≦⁠)

[@SegHaxx]

i'm 43 years old and i've only ever read about machines like the Bendix G15 in history books. teenage me never imagined i'd ever see one running in HD hope i can write code and see it run on this one someday soon!

[@ct92404]

I'm about the same age. I remember in school reading about computers during WWII and the 1950's that took up entire rooms, but I never learned anything about how they actually worked. So yeah, this is awesome seeing one function! I hope someday I can go to the museum and see it in person.

[@paulwomack5866]

You can start writing code now - there are emulators "out there"

[@ct92404]

@@paulwomack5866 There are emulators for this computer? That would be pretty cool to try out!

[@halfsourlizard9319]

This literally got ur girl crying: Couple of nerds from different generations powering up + debugging a beautiful piece of history + getting those sweet toobs churning out some heat again. Can't wait to see y'all programming that thing and getting that teletype kerchunking away: I'm really interested to get a sense of what the programming model is even like -- I gather that you need to configure the hardware first for whatever problem you're doing (swapping cards in / out / moving them around), but I'm totally clueless what the capabilities of the machine are and what interacting with it looks like. Hard to imagine a time before a Unix-style command-line ... love seeing history coming alive.

[@UsagiElectric]

Glad you enjoyed it! The machine is actually a proper general purpose computer, no need to change any hardware. All you gotta do is write a program, punch it on a paper tape, and load it in, not all that different from writing programs and loading them from floppies. Granted, the baremetal programming language is very... weird, it's still a surprisingly modern style of computing!

[@halfsourlizard9319]

@@UsagiElectric Neat! Looking forward to seeing the whole process + what the language is like :}

[@PCFixer]

This is the most bonkers machine I've ever seen, and I love it!

[@halfsourlizard9319]

@@PCFixer I've seen one (non-operational) in person at a museum. They sure as hell don't build em like that anymore!

[@TheRetroBristolian]

So pleased to be a patron of the channel, the fact you specifically waited for Lloyd to be able to join you shows what a gent you really are. Love the series - keep up the good work!

[@UsagiElectric]

Thank you so much! I couldn't push the button without Lloyd there, he's been a massive help and it wouldn't have been right doing it without him!

[@kromaine13]

Lloyd noticed your suspenders, guess old computer tech's like us wear suspenders today. Regards, Ken

[@mrshimmy1999]

So we have a keyboard error halting startup😂. So close, I can't wait to see it up and running.

[@SeanBZA]

With no F1 key available to press either, because the keyboard is faulty. My bets are crusty paper capacitors, and a shorted diode, along with some contacts that are dirty as well.

[@peevester9987]

I don't know about the Bendix, but on mainframes of the 60s and 70s era, the console typewriter was critically important, and nothing could start up if one wasn't connected and responding. At minimum, you needed the keyboard to issue a command to start up a card reader or allocate a tape drive to system input so that jobs could be loaded. Eventually the basic startup sequence was built into the operating system disk volume (called the SYSRES) and the typewriter became a terminal - often a gas plasma display.

[@paulcarboneNY]

The only thing missing is a period correct Tektronix 500 series scope :)

[@JanusCycle]

I really appreciate that you make videos about these larger computers. They are so much harder (and heavier) to ship around, and even just move them about in your workspace. The effort you go to is amazing, thank you David.

[@Putersdcat]

Watching Lloyd work those indexed trim pots to balance the DC rails was pure magic, like watching a pilot fly by instruments

[@simonstergaard]

Freaking EPIC... Loyd you are the man !!! You gotta interview him about his professional life.. we want to know

[@anotheruser9876]

David, you can zero out your test leads on the DMM by pressing the ZERO button whilst shorting the leads. This makes for the offset of the test leads resistance to zero thus a more accurate reading.

[@anthonyblacker8471]

Wow to have Lloyd living 2 hours away and he was a TECH back in the 70s working on these thing?!?! A MA ZING! I know this has been posted already down here but I had to say it myself.. you hit the jackpot, what a win!!

[@shawnerz98]

Congratulations in getting this far with the G15. Looking at the size of that thing, I'm sure ERCOT thanks you for your support! 😁

[@UsagiElectric]

Now that it's a wonderful 100+F out everyday, we can only run it for about 20 minutes before it fully overwhelms the A/C in the room, haha.

[@eDoc2020]

@@UsagiElectric I'm guesstimating it buts out about 16,000 Btu/hr of heat, which is coincidentally about the capacity of the largest window Ac capable of running from a standard household outlet.

[@jscollett]

Lloyd sounds like a Legend.

[@toresbe]

I'm hanging on every episode, but very good of you to wait! I wish both him and the Bendix a full recovery. :)

[@mistermac56]

Great to see the "big iron" G15 come up as far as it did. Now getting the fiddley typewriter interface repair hurdle cleared will be interesting to see and find out if the computer will read the punched tape and the G15 goes fully up. A great milestone that the rotating drum is functioning properly.

[@sign_verken]

I have a massive respect for past technology, especially when it was made to last

[@OtherWorldExplorers]

Thank you Lloyd!

[@CATech1138]

Hi Lloyd...thank you for adding to my vacuum tube computer curiosity.

[@monnierobinson9210]

Your attention to finding and noting others in your work is commendable. Very happy to see big blue coming back to life with Mr. Lloyd's incredible help.

[@allanhiggins313]

Okay, I don't understand the technical stuff, but I am now pumped up to see the next video on this machine. It's like watching your country's athlete about to win an olympic medal. Go G15, GO!

[@sn1000k]

This is so exciting David, even just to see those lights on! This is my favorite project of yours, perhaps aside from your 1-bit vacuum tube system. Thanks to you and Lloyd!

[@captainchaos3667]

I had no idea that it had a link right back to the father of digital computers. That's amazing.

[@FaveMage81407]

Glad to see you have Mr. Lloyd "The Living Legend!" on the show today. It's amazing to know that there are still people that know how to operate these machines and you all to share this with us!❤

[@chriswareham]

Having Lloyd, someone who worked on these machines when they were still in active use, relatively close to where you are and also restoring another G15 is mind-blowing. What an incredible episode in the resurrection of this machine!

[@IBM_Museum]

I half-expected to see something about a razor/shave sponsorship on this video - after I told you at VCFSW (for apparently the second year running) that I was going to shave my beard off again. Here I am, I still have mine. It's itching to come off.

[@UsagiElectric]

I was contemplating whether to shave it or not, but ultimately, it turns out I'm terrible at getting food into my mouth and I had to clean the beard after dinner one day, haha.

[@IBM_Museum]

@@UsagiElectric: Yep - Young people don't know the struggle. Now that I've been through the 4th of July parade to demonstrate an old veteran, I'll probably shave it off to start fresh (I've looked like AJ at times before). Not that I don't have the food issue, but my skin gets dry underneath, too.

[@frankowalker4662]

Big thank you to Lloyd. This is so cool.

[@chrislittle5958]

FINALLY. This is my favorite project!!

[@TastyBusiness]

Excellent progress, that's a great step in the right direction. I'm excited to see this thing running! Oh, and nice shirt at 12:36!

[@braddofner]

This is great! You have one of the coolest hobbies, and you're awesome at it. Good job keeping these old systems alive and running. They are important history and I love that other people with more skills than me are doing something to keep them around.

[@AxelWerner]

WOW! The tension!!!! SO CLOSE TO LIFT OFF !!! Come on!!! I want to see that baby running !!!! 😍

[@tarstarkusz]

Many thanks to lloyd for helping bring this project so far. Can't wait to see it up and running.

[@mar4kl]

I've enjoyed watching your channel on and off, because you're featuring the computers that were in use when I was growing up, but this is one that date back to before I was born! I just subscribed to ensure that I don't miss anything. Keep up the amazing work.

[@johncloar1692]

Can't wait until the next episode!

[@intheprettypink]

Would love an interview with Lloyd, Im sure he has some stories to tell!

[@DonnyHooterHoot]

Lloyd! KZbins next SUPERstar?! Yes! Cool viddy!

[@ct92404]

That's so awesome that you met someone who actually worked on these machines! You are so close now to getting and working and saving a piece of history!

[@cpunut]

I love your videos and sense of humor! I'd be so tempted to try to fool the computer with whatever handshake it needs to think the printer is there just to take it out of the loop. Of course I don’t know how difficult that would be. Anyway I'm an embedded electronic and firmware engineer from the late 70s for some decades. I look forward to your next videos. The tube computer you're building on the wall is very cool, long live the 6AU6 😎

[@tobitweaks]

So cool how you bring people together with your projects! Loved watching the last episode with forgotten machines too!

[@UpLateGeek]

That's so awesome that you found someone with experience working on this machine who was willing to help you get it up and running!

[@xephorce]

Im loving this. this long journy has been so fun. thank you and Loid for all this. and the people that loned it to you thank you.

[@ricardog2165]

The inside of that typewriter looks nasty. It needs a deep clean and lots of continuity checks.

[@emilschw8924]

What if the solution to this fault is a simple "paper out" error and you'll just need to have some paper loaded in the printer/typewriter to proceed? 😂 Edit : There was already paper loaded in the typewriter (have asked the same question on the discord channel). So the problem goes deeper than that. Should be interesting. My only hope is that the typewriter is compatible with the Bendix.

[@danaeckel]

OMG that could be so possible, loading it with paper would flip the switch to send the -20v the system is waiting for.

[@AndersNielsenAA]

I bet it feels like the captain in Wall-e at this point: “I don’t want to survive! I want to LIVE!” 🎉 🚀

[@Verightess]

Poor Lloyd, He looks really camera shy.

[@supercompooper]

He seems sweet

[@Tony-he8ze]

I've always brought up old lytics (that have been sitting for years/decades) in at least 20% 20-minute increments to repolarize the electrolyte.

[@deejayy3421]

HEY ALRIGHT!! My favorite project of yours

[@levimluke]

Lloyd! You’re amazing - thank you for joining the community for this monumental occasion! 🎉

[@your_utube]

"put things on paws till his foot healed" sounded so much like a pun!!

[@FirstWizardZorander]

Imagine not being able to boot your computer because your typewriter doesn't work 🤣 Excellent video as always, and a great window into the very early days of computing. Just the fact that the clock of the machine is derived from a rotating drum is hard to wrap my head around as someone who grew up in the 90's!

[@SobieRobie]

Congratulations guys! I'm looking forward to see the machine fully working!

[@raymitchell9736]

Congrats getting to this point of the system bring up... A lot has to work to get to that point. I'm sure you'll have it sorted out soon and what a blessing that you have Lloyd to help you out.

[@jarms40]

Listening to this episode on my Quicksilver Audio system: Line Stage Preamp (12AX7 output tubes) and GLA power amp (KT88 output tubes). I thought this was... appropriate.

[@Willow1w]

Thanks Lloyd! Stellar job!

[@simaesthesia]

2:50 put things on paws? 🤣Fantastic update and repair. Thanks!!

[@woldemunster9244]

Hi Lloyd, nice to meet you! :D

[@TechTimeTraveller]

Marvin the Martian: "Where's the kaboom? There was supposed to be an earth shattering kaboom!" (I was picturing it turning out to be a component of a Duck Dodgeresque space laser system.. not hoping it'd blow up when reset was pressed lol)

[@UsagiElectric]

It is wild to me that this thing is quieter than the Centurion when it's on. But don't worry, it puts out about the same amount of heat as an earth shattering kaboom!

[@mikafoxx2717]

Hope you have a good air conditioner in the computer studio this summer! @@UsagiElectric

[@TechTimeTraveller]

@UsagiElectric Old machines that are quiet seem unnatural, don't they? If I turn something on for the first time and it's quiet like that, I think it's just taking a few seconds to pull the pins on all its tantalum smurf grenades before tossing them at me.

[@exidy-yt]

WE GET SIGNAL! WHAT? MAIN SCREEN TURN ON! I'm so happy you are so close and glad that Lloyd could come down for this, you can see his clear competence and familiarity with the machine, and I can't wait to see the final complete init and this beast start to execute real code. I love how both primitive and complex these ancestor machines are, and so glad you have the love to get these going again Dave. Can't wait for the next ep!

[@jasonhaman4670]

You, sir, are a double legend. A legend first for your knowledge, skills and incredible accomplishments resurrecting these historically important almost-lost-to-time systems. A legend second for gathering a legion of veteran legends, who designed/worked on/used these systems in their heyday, working with them to bring them back to life, and documenting them and these computers for posterity. You are absolutely right that Lloyd is a legend, and thanks to you, we all know of him, and have seen him working on this computer. It is truly awesome what you have accomplished, and continue to accomplish.

[@toonvanderpas7604]

wow, what a great adventure this is! Please don't make us wait another 2 months for the next episode. I enjoy it sooo much!

[@kenrowe167]

Jumper the relevant line to -20v to simulate the signal from the typewriter to see if the start sequence progresses further.

[@UsagiElectric]

By the time we realized what was holding up the boot process, it was already getting quite late in the day, so we threw in the towel. That SA line is quite important for the rest of the machine and other parts of the boot process. We want to be absolutely sure we're doing things the right way so we don't damage anything else or break the boot process in an even more difficult to troubleshoot way.

[@chrisc1553]

I am so glad i've found your channel i've been drooling over these computers since middle school its amazing to see one so close to running and follow your adventures getting it there

[@brunogrieco5146]

Keep on the good work, man. We are rooting for you !!

[@HenriqueSilveiraSteinmetz]

on the side panel shown at the end of the video there is a connector for -20v and one for GND, what would happen if you put the -20v that the panel asks for?

[@ppokorny99]

Yeah, just wire the SA to -20 and don’t mess with the typewriter

[@anthonyblacker8471]

I love your enthusiasm on this one.. this is iconic to say the least! Nice job

[@kelli217]

Lloyd is probably _the_ guy to have around to help you with the typewriter... but you should have Curious Marc on standby too. 😉

[@RingingResonance]

The video we've all been waiting for. Can't wait to finish watching it. Great job! One day I will amass a collection to rival yours.

[@the21tinker]

Lloyd the legend! You guys made my day!

[@pjcnet]

I've been waiting for this and so close, an incredible achievement so far.

[@baronvonschnellenstein2811]

What a cool episode! Great to see Lloyd there to push the big green button and lend his expertise. So, down the next rabbit hole to sort/decode the internals of that teletype - At the moment, it seems to be like a mudguard: Shiny on top; Pretty crusty underneath, rofl!

[@bobclem-mh3ot]

I love your channel. Thank you for producing such wonderful content. Also, thank you Lloyd for helping, I hope your machine is running soon as well.

[@thek3743]

you are VERY optimistic! still very exciting!

[@wtmayhew]

Superb work! Thanks.

[@jk180]

Glad you're doing better Lloyd! Glad to have eyou on the channel. David likes to break things (HAHA).

[@LarryBlowers]

Im so excited every time i watching your videos just so awesome seeing you restore life to so many computers built around and even before the time i was in the early 70s!! Keep up the awesome work!

[@mwk1]

Fajny ziomuś ten Lloyd 😎

[@nice8D]

Absolutely amazing! I hope I get to see this running in person one day!

[@sildesrosa2791]

Epic! It is almost there! Congrats!

[@PixelBrushArt]

Looking forward to seeing more!

[@ReallifeBambiDeerattheFarm1]

This is so cool! So close to getting it going again. Can't wait to see what you can do with it. Cute bunny at the end!

[@flyingdutchman28]

Thanks Loyd! Thanks Usagi! You guys are awesome!

[@TOONMAN200]

Well you're getting there, a little bit at a time step-by-step. I've been following the G 15 from the beginning, so excited were getting close to a boot. Good luck with the next step you're getting closer.

[@rlzr.]

Oh man, I am just starting to watch this episode and already I am feeling excited! :D

[@sjfriedl]

Fun to see on the drawing @17:32, lower right the phrase: "tantalytic capacitors", which is a new phrase to me but whose meaning is obvious.

[@AnnaVannieuwenhuyse]

A contraction of tantalum electrolytic capacitor, which we colloquially call tantalum capacitors these days due to the rarity of intentionally dry tantalum capacitors.

[@heckelphon]

Of course, etymologically, that means they must tantalize either the beholder, or the rest of the circuitry!

[@lreid2495]

Pleased to meet you, Lloyd. Fantastic.

[@louwrentius]

This machine is so interesting ❤

[@delmonti]

...wow! welll done for getting so far!

[@lerkzor]

"He injured his foot, so we had to put things on paws" Oh lord, I am so sorry, but I simply HAD to!

[@waxore1142]

loyd lmao you look so thrilled to be on camera!

[@2packs4sure]

I didn't want to do it without Lloyd even before I knew Lloyd existed !!! :)

[@JeepinBoon]

I love it! Keep going!!!!

[@insanelydigitalvids]

So kind off you to wait until Lloyd was able to attend the start up of the Bendix 🙂

[@GilgaFrank]

Regarding checking the big filter caps on vacuum tube circuits - I assume you're aware of Mr Carlson's Lab channel and the very clever capacitor tester he has designed and built?

[@hubbsllc]

"1954" is the only cap testing I need to know in this case! :)

[@labcat73]

Awesome video! 🐰 Thank you.