Congrats! Tape data loading onto the drum! That’s quite an achievement. It’s really neat to see the data build up on the track at the pokey speed it’s read in from the tape. Such a relaxing computing pace.
Thank you! Interestingly, what we're seeing on the scope is incrementing four words at a time, so that's actually 116-bits being transferred over at a time, which is decently fast!
You have the best ability to convey complex computer jargon that I could never understand on my own. I appreciate you saving historical items like this and sharing. Many thanks. Always enjoy watching you.
Thank you so much! The G15 is quite a complex system, even something as simple as loading in paper tape data is a fairly difficult system to understand, so I definitely wanted to take the time and explain it as clearly as I could!
That single scope shot made the entire input system click in my head and really helped me understand what was going on! Also, it was just super cool to see the data push around the drum line!
Fun fact, an ordinary LED can act as a photo-diode that’s most sensitive to light with the same wavelength as it would emit (does NOT apply to blue/white LEDs). Since that bulb probably emits a good deal of light across a broad portion of the visible spectrum, a yellow SMD LED glued to the end of a light-pipe with the same diameter as the bad photo-diode should work; just keep in mind that LEDs of any color have a low PIV (Peak Inverse Voltage), should you try to use them as photo-diodes in a tube circuit! 😊
I was wondering about that myself, in fact it was the first thing I thought of when the germanium photo-diode was confirmed toast. Not even sure where I heard this fact but it clearly stuck in my subconcious somewhere!
Unfortunately it can't. I spoke with David when he was at Systems Source removing the good drum from the Bendix they have on display. I said the very same thing, "I cant wait for it to print out 'Hellorld'." David said it cant, since the Bendix is a numerical computer only. It can't do alphanumerics. Therefore no letters. The closest he could get would be printing images of the Hellorld letters. I hope he can get that far.
I've been watching a lot of this and I'd like to thank not just you but Mrs Bunny and all the little bunnies. There's a lot of sacrificing going on making these videos for us and working on this hardware. And I want you to know it's greatly appreciated. 😊
Excellent work. Won't post any spoilers here, but your solutions to problems are innovative, and, more importantly, _functional._ Well done, both of you!
First let me say: Lloyd, you are a bloody legendary hero to keep coming to restore this old beast from your working days back to life and we totally appreciate you! Grats Dave! PLEASE keep focus on this machine until it's 100% rather then cycling through projects if possible (and if Lloyd's schedule allows) because it's SO close I am all but dancing on my toe-tips here. I cannot believe how invested i've gotten into seeing the Bendix run, it's worse then with the Centurion that got me hooked on your channel in the first place, LOL.
Wow wow wow, thought I'd be one of the first to say congratulations, been following this with interest from the start, now I'm watching the full video.
This is quite an odyssey! But I'll follow your Bendix exploration as long as it ever may take. This machine has something incomparable to it. You're doing a fascinating and invaluable job by restoring this machine, your patience and resilience are admirable! All the best of luck to you and your mates and family!
Absolutely fantastic. I was quite Skeptical that it would ever live again, "Bit more then you could chew" type of thing. But you and the community has shown, there is bite to that bark. I am in awe!
Just gotta say, I love the editing in the crosstalk between Dave and Future-Dave. You are approaching Jedi level Youtubing skillz. The self-deprecating comments are fun, too. 'Uncoordinated monkey' had me snorting my coffee.
Thank you for again an exciting episode. It feel like a real thriller to me, with a positive ending every time. I love you man, and am looking forward to the new episode every sunday. Thanks again!
If you cannot find an exact photo diode you could put a fiber optic cable in its place and run it to another location where you can then use some other photo diode that is larger.
I recently made the mistake of falling down the electrical engineering youtube hole. After watching a lot of the videos with Robert Feranec and Professor Bogatin... that impedance and crosstalk is nuts, and yet I know that was common and even "fine" until computers and signals started to get up to the speeds where it actually matters. The fastest rise time on a G15 is microseconds, not the nanoseconds or even picoseconds we have on modern devices. So it's perfectly ok to have common mode noise that would absolutely destroy faster devices. That's my nerdy aside. I find it fascinating just how much things have changed and yet stayed the same. The G15 designers were almost certainly worried about interference from the longwave or AM bands. Whereas now a PCB designer would be worried about switch mode power supplies or wifi.
I don’t know anything about tape computers or the bendix g15 and I have really only watched maybe 5 or so of your videos but I have to say these old printed diagrams are so charming. This has to be the first time I have sat through all of a troubleshooting montage where I didn’t understand hardly a god damn thing besides the fundamentals of basic signals and logic, and I think this speaks to the excellent editing and explanation at each point While I didn’t know what the fuck a bendix even was before a month or two ago I can say you’ve got 2 more eyes and ears patiently waiting to see this project through
Maybe an octopus curve tracer would be an easy way to test diodes under higher voltages? I'm a little sad to see the beard go, I don't know if you've ever watched the anime Gintama, but with the beard you always make me think of Makoto the mascot. I have a mental image of you as Makoto with a G15 slumped over your back.
Hi I was sure I had at least one of those diodes but for now it is lost. it probably was from our early IBM, it was black in color. I think you could use a photo diode attached to the correct size light pipe to do what you need. I will keep looking. Rich
Man David, I really envy how clean you look freshly shaven. I havent looked like this since I was 15, when I shave I look like I havent shaved in three days afterwards 😂
🎉 Nice! Maybe the diodes are bad in the sense that their breakdown voltage has decreased to something lower than the one they need to block. So the meter's low voltage test doesn't trigger the failure.
With a function generator, a resistor and your scope, you can create a curve tracer for the diodes. It may be that the breakdown voltage on the bad one is very low. BTW: I have found that a 1N5711 works OK as a replacement for a 1N34 in some circuits. The signals you have a large enough and slow enough that it is likely that the details of the diode don't matter much. The BAT41 is a 100V diode. I think you are only running about 25V on those diodes so that should be OK A conventional silicon diode would likely work for you if you need a higher voltage part
I would (well I did, not with bendix though) make a set of replacement diode cards to keep round, you can easily match a modern shottkey to a germanium diode at those speeds.
Great video. I was thinking couldn't you just take a normal photodiode, add a small tube to that, extend the wires and hotglue it in the small tube.Something 3d printed perhaps.
Nice! Sooo close!!! Can’t wait to see that sucker taking in I put from the teletype and sending out results! Wonder if it would be emulated with like an Arduino? Certainly a Pi could do it… I almost wonder if it would make sense for debugging to build some sort of interface to an Arduino that would allow it to act as a live data watcher.
Anybody know how to connect this guy?! I posted months ago that I owned a g15 AND I have new old stock parts INCLUDING a full set of replacement photo diodes. Obviously he doesn’t read responses to the video
vacuum tubes are illogical. lol. when you need computers, instead of hand calculations, one might ask why. some people do need diapers. especially when shorting.
i wonder how the IPS compares between the those 2 cpus and would there be an increase or decrease in the amount of bits/data/instructions that have to be processed to reach a prompt on an output terminal.....and what is the increase in kilo-wattage to get there....i think the ratio would be some thing like 1/2 hour of G15 = boot to prompt on the 4004 with the G15 taking a week longer, but enquiring minds want to know.
Congrats! Tape data loading onto the drum! That’s quite an achievement. It’s really neat to see the data build up on the track at the pokey speed it’s read in from the tape. Such a relaxing computing pace.
Thank you!
Interestingly, what we're seeing on the scope is incrementing four words at a time, so that's actually 116-bits being transferred over at a time, which is decently fast!
"...anyone else restoring a Bendix G15..." I'd say that is a pretty rarefied group! 😁
You can probably count the number of us on one hand, haha.
@@UsagiElectric
@@UsagiElectric So debate in the community means you are feeling divided?
You have the best ability to convey complex computer jargon that I could never understand on my own. I appreciate you saving historical items like this and sharing. Many thanks. Always enjoy watching you.
Thank you so much!
The G15 is quite a complex system, even something as simple as loading in paper tape data is a fairly difficult system to understand, so I definitely wanted to take the time and explain it as clearly as I could!
Congratulations! When I saw the data build up on the drum through the oscilloscope, I gasped!
Yes, that was awesome!
That single scope shot made the entire input system click in my head and really helped me understand what was going on!
Also, it was just super cool to see the data push around the drum line!
I know right? It was like the midcentury equivalent of a progress bar, so cool!
Fun fact, an ordinary LED can act as a photo-diode that’s most sensitive to light with the same wavelength as it would emit (does NOT apply to blue/white LEDs). Since that bulb probably emits a good deal of light across a broad portion of the visible spectrum, a yellow SMD LED glued to the end of a light-pipe with the same diameter as the bad photo-diode should work; just keep in mind that LEDs of any color have a low PIV (Peak Inverse Voltage), should you try to use them as photo-diodes in a tube circuit! 😊
I was wondering about that myself, in fact it was the first thing I thought of when the germanium photo-diode was confirmed toast. Not even sure where I heard this fact but it clearly stuck in my subconcious somewhere!
@@exidy-ytanother fact: these photovoltaic panels can also work in reverse, just not for long and not well, they emmit a light close to or at ir.
Good idea. Alternatively an ordinary through-hole yellow LED of the correct size may do the job sans light pipe.
@@SimonBauer7 So do transistor junctions....
so you add more resistors to drop volts in and an amp tp up volts out ?
The Bendix is by far my favorite of all your vintage machines. Getting closer to fully operational! I can’t wait to see it print out “HELLORLD”.!
Unfortunately it can't. I spoke with David when he was at Systems Source removing the good drum from the Bendix they have on display. I said the very same thing, "I cant wait for it to print out 'Hellorld'." David said it cant, since the Bendix is a numerical computer only. It can't do alphanumerics. Therefore no letters. The closest he could get would be printing images of the Hellorld letters. I hope he can get that far.
Me too! Been waiting for this great day! Congrats.
I've been watching a lot of this and I'd like to thank not just you but Mrs Bunny and all the little bunnies. There's a lot of sacrificing going on making these videos for us and working on this hardware. And I want you to know it's greatly appreciated. 😊
Excellent work. Won't post any spoilers here, but your solutions to problems are innovative, and, more importantly, _functional._ Well done, both of you!
Diaper = diagnostic program for easy repair. This one wins the "catchy acronym in the IT industry" award easily.
I thought it was a silly name until I saw the acronym, then I immediately loved it, haha.
@@UsagiElectric nearly as good as the WIPL ? and others for the centurion ?
Now we know why they named it DIAPER - because when it finally works, you load up your pants in astonishment! Great job!!!
I got a good laugh out of the "You Wanna Bet?" that someone wrote on the schematic at 21:28. So cool to see this coming back to life!
Awesome. You are slowly becoming a master of the G15.
Oh, I'm still a long ways off, Lloyd is the master for sure!
I've never seen someone so happy about a loaded diaper.
Congratulations! A big round of applause for you an LLoyd.
Came for clean shaven Dave. Stayed for the working Bendix
Every once in a while, I gotta get 10 years younger overnight by shaving it off!
@@UsagiElectric you do look so young without it!
First let me say: Lloyd, you are a bloody legendary hero to keep coming to restore this old beast from your working days back to life and we totally appreciate you!
Grats Dave! PLEASE keep focus on this machine until it's 100% rather then cycling through projects if possible (and if Lloyd's schedule allows) because it's SO close I am all but dancing on my toe-tips here. I cannot believe how invested i've gotten into seeing the Bendix run, it's worse then with the Centurion that got me hooked on your channel in the first place, LOL.
I knew you would be able to replace the photodiode. Congrats on this great repair!
Congratulations David. It's been a long road but I've been with you step by step.
That's a big step forward! Interesting to see how things were done in the 50's.
A journey of a thousand miles started with a single step.
An most excellent troubleshooting process, and it is so awesome.
Thanks for sharing!
Congratualtions :) :) Really looking forward to the next epic chapter.
Incredible work! You guys are the pioneers of G15 restoration.
Congratulations! Excellent progress. Can't wait to see the next step.
Wow wow wow, thought I'd be one of the first to say congratulations, been following this with interest from the start, now I'm watching the full video.
This is quite an odyssey! But I'll follow your Bendix exploration as long as it ever may take. This machine has something incomparable to it. You're doing a fascinating and invaluable job by restoring this machine, your patience and resilience are admirable! All the best of luck to you and your mates and family!
Absolutely fantastic. I was quite Skeptical that it would ever live again, "Bit more then you could chew" type of thing. But you and the community has shown, there is bite to that bark. I am in awe!
Wow! Saving the past for the future, bravo.
That's awesome work on the tape reader.
Last night an old video showed up in my feed about a G15 boot process. Then I see this in the morning. Neat coincidence LOL.
Amazing to see the data building up on the drum in real time.
So cool.
What a neat machine. Glad that new drum works after all these years. It was crazy that he was even able to get a spare.
Congratulation to both you and Loyd, seeing the neons flicker must have been amazing!
Just gotta say, I love the editing in the crosstalk between Dave and Future-Dave. You are approaching Jedi level Youtubing skillz. The self-deprecating comments are fun, too. 'Uncoordinated monkey' had me snorting my coffee.
Thank you for again an exciting episode.
It feel like a real thriller to me, with a positive ending every time.
I love you man, and am looking forward to the new episode every sunday. Thanks again!
If you cannot find an exact photo diode you could put a fiber optic cable in its place and run it to another location where you can then use some other photo diode that is larger.
Pretty cool becoming one of the very few Bendix techs. Excellent progress!
Awesome!!!! Cool to see the blinking lights... it isnrunning someting... that's cool! Grettings from Brazil....
Incredible work! You are an inspiration!
You’ll get it working!
[Borat Accent] - HIGH FIVE!!!
What a great episode, good luck with the rest of the restoration.
I cant wait for the G15 to load POTTYTRAINING, the sequel to DIAPER
The engineers named it "Diaper" 😂 perhaps a bunch of young new parent engineers working in the team
Insane, can't wait to watch this one...
What a milestone! Congratulations!
I recently made the mistake of falling down the electrical engineering youtube hole. After watching a lot of the videos with Robert Feranec and Professor Bogatin... that impedance and crosstalk is nuts, and yet I know that was common and even "fine" until computers and signals started to get up to the speeds where it actually matters. The fastest rise time on a G15 is microseconds, not the nanoseconds or even picoseconds we have on modern devices. So it's perfectly ok to have common mode noise that would absolutely destroy faster devices.
That's my nerdy aside. I find it fascinating just how much things have changed and yet stayed the same. The G15 designers were almost certainly worried about interference from the longwave or AM bands. Whereas now a PCB designer would be worried about switch mode power supplies or wifi.
Good Job, David. :) -Thom
I don’t know anything about tape computers or the bendix g15 and I have really only watched maybe 5 or so of your videos but I have to say these old printed diagrams are so charming. This has to be the first time I have sat through all of a troubleshooting montage where I didn’t understand hardly a god damn thing besides the fundamentals of basic signals and logic, and I think this speaks to the excellent editing and explanation at each point
While I didn’t know what the fuck a bendix even was before a month or two ago I can say you’ve got 2 more eyes and ears patiently waiting to see this project through
Maybe an octopus curve tracer would be an easy way to test diodes under higher voltages?
I'm a little sad to see the beard go, I don't know if you've ever watched the anime Gintama, but with the beard you always make me think of Makoto the mascot. I have a mental image of you as Makoto with a G15 slumped over your back.
ITS ALIVE !!!!
Mmm good....
There are also 0805 SMD photodiodes cheaply avaiable, did you ever think about glueing those to some sorts of a stick and soldering tiny wires to it?
Usagi: Electric Bootaloo, DIAPER party.
Hi I was sure I had at least one of those diodes but for now it is lost. it probably was from our early IBM, it was black in color. I think you could use a photo diode attached to the correct size light pipe to do what you need. I will keep looking.
Rich
Excellent, I share your enthusiasm
Amazing! I love this series.
Congratulations nice milestone reached!
epic, so much fun watching this journey!
Wow, what a feat!
That is so cool that its got to that point.
Me: ‘is the new silicon diode gunna work???”
Also me: *looks at the video title* ‘yeah, probably’
Congratulations!!! 🎉 What a huge milestone!!🎆🎇🎉🎶🎵🎶🎵🎶😎
Man David, I really envy how clean you look freshly shaven. I havent looked like this since I was 15, when I shave I look like I havent shaved in three days afterwards 😂
HELL YEAH! LETSGO!
🎉 Nice! Maybe the diodes are bad in the sense that their breakdown voltage has decreased to something lower than the one they need to block. So the meter's low voltage test doesn't trigger the failure.
With a function generator, a resistor and your scope, you can create a curve tracer for the diodes.
It may be that the breakdown voltage on the bad one is very low.
BTW: I have found that a 1N5711 works OK as a replacement for a 1N34 in some circuits.
The signals you have a large enough and slow enough that it is likely that the details of the diode don't matter much.
The BAT41 is a 100V diode. I think you are only running about 25V on those diodes so that should be OK
A conventional silicon diode would likely work for you if you need a higher voltage part
Congrats!
FUCK YEAH!
Wow, you could be Shane Bourne's doppleganger, Australian Comedian.
I would (well I did, not with bendix though) make a set of replacement diode cards to keep round, you can easily match a modern shottkey to a germanium diode at those speeds.
Sorry…. There is only one 👍 button 😢 . This video deserves many!
Great video. I was thinking couldn't you just take a normal photodiode, add a small tube to that, extend the wires and hotglue it in the small tube.Something 3d printed perhaps.
Did I spy a Bendix card test jig?
I saw that too, amazing that parts like that are still around at all!
Good work. 👍
Nice! Sooo close!!! Can’t wait to see that sucker taking in I put from the teletype and sending out results!
Wonder if it would be emulated with like an Arduino? Certainly a Pi could do it… I almost wonder if it would make sense for debugging to build some sort of interface to an Arduino that would allow it to act as a live data watcher.
an arduino could probably emulate the entire machine.
Congratulations 🎉 this is amazing! So close you can taste it right?
Bring back the beard! 🧔
Very well done ^^
Swap diode 2 with the sprocket diode?
Or recover a Diode from the other G15 machine?
I'm loving that Bendix have a D1/2/3/4 card test rig 🙂
Awesome man! Although the -1 to constitution when you shave your beard is a no no 😊
I think to convert to silicon, you may need to change a resistor value or capacitor value.
Awesomesauce!
DIAPER - it makes sense because it s#!+ itself
I can't wait till you get it running code "right".
Do you have a link to the video you inserted that showed the IBM 650?
this might be a stupid question but how did they test this stuff back in the 50's or did they already have replacement parts and just swap it out
the same way, oscilloscopes were a thing in the 50s too...just not modern digital ones. or they just swap the entire reader, which i doubt.
awesome video
No beard makes you look younger in spite of your gray hare. 😂
Woohoo 🎉
A path for anyone else that has a G15 ? - how many is that - and are they all in the US?
Isnt a photo diode a LED in reverse ?
Is that Mylar tape?
What's that big motor behind the tape reader for?
Baby face 😅😅
Anybody know how to connect this guy?! I posted months ago that I owned a g15 AND I have new old stock parts INCLUDING a full set of replacement photo diodes. Obviously he doesn’t read responses to the video
But can it run "hello world"?
You mean "Hellorld"? Yeah, that's what we're all looking forward to.
1:53 is that autotune?
I do not use Diapers thank you
vacuum tubes are illogical. lol. when you need computers, instead of hand calculations, one might ask why. some people do need diapers. especially when shorting.
weii done
Next step is to get it to run Linux. Someone managed it on an Intel 4004 chip.
i wonder how the IPS compares between the those 2 cpus and would there be an increase or decrease in the amount of bits/data/instructions that have to be processed to reach a prompt on an output terminal.....and what is the increase in kilo-wattage to get there....i think the ratio would be some thing like 1/2 hour of G15 = boot to prompt on the 4004 with the G15 taking a week longer, but enquiring minds want to know.
Can it run doom?
But can it run Crysis?
@@RaymondSwanson-u9y maybe
Imagine a Beowulf cluster of B15 machines?
10th comment ;D