I Was Wrong… and It’s Awesome!

[@Wayde-VA3NCA]

Lbs per MB is a cursed unit that I never knew I needed 🤣

[@HubrisInc]

MB/Lb might be a more useful unit with modern storage media 😅

[@danl6634]

​@@HubrisInc a gallon milk jug stuffed with microSD cards would beg to differ, more like petabytes per lb.

[@HubrisInc]

​@@danl6634fair!

[@HwAoRrDk]

I'm not sure we have enough decimal places to represent the ratio of lb/MB for a modern 1TB MicroSD card. 😅

[@mukiex4413]

13.5 pounds per megabyte comes to a mere 0.21 ounces per kilobyte! 0.0897 grains per byte! =D BTW, 1TB MicroSD is 0.16 ounces.

[@ve4edj]

Came for the Centurion, stayed for the hard drive history lesson

[@Pistoletjes]

don't forget the nom nom nom

[@UsagiElectric]

I always love me some good old spinning rust!

[@falksweden]

"Keep the room in a known good state." That's an excellent policy, I'll remember that! 😁

[@spacewolfjr]

Lettuce give thanks for Mr. Romaine, he's done for the Centurion what his family has done for salads!

[@wa4aos]

As a retired DEC FE, I got to tell you lifting heavy devices, especially at your somewhat advanced age, will catch up with you and fry your L4 L5 vertebra. I just had surgery June of 24 after YEARS of extreme pain and downing Tramadol. At the VERY LEAST, get a back brace like the ones made by Aspen or something equivalent. You've been warned ! Severe back pain is the worst !!!!

[@cathrynm]

Oh yeah, 135 pounds is beyond my personal limit. If it's above 50 pounds, I call someone.

[@6LordMortus9]

@@cathrynm With two minor hernias, my recommended limit is 20 lb. And from what I know, most regulations for work places state that anything over 50lb is a two person lift.

[@KameraShy]

@@6LordMortus9 Three hernias for me. You do NOT want them.

[@ralfbaechle]

At my previous work they had signs about weight limits for lifting. Different limits for lifting from floor, knee lever or higher. I think there was a 2nd set of limits for women which was slightly lower. The highest weight was 25kg. I know people who had to change their profession at less than half my current age due to back injury. I regularly exceed that 25 kg limit but almost always that's doing sport which I think - and that's confirmed by scientific literature - helps drastically. No issues whatsoever. Sadly in the big iron league of retro computing a hawk drive is just a feather weight, so be careful folks.

[@CaptainRon1913]

I don't need a back brace for lifting a beer, do I?

[@horusfalcon]

Admitting when one is wrong is a highly desirable trait in a technician. We learn from our mistakes, and grow as a result. Thanks for showing us that side of the vocation. If you're going to continue to play with all this heavy iron, you might invest in a hydraulic or pneumatic platform lift with some heavy casters on it. Might save your back. Fitting the worktable with some rollers would make it too easy, but then you'd want some straps to secure the load in transit. 😆

[@johnvanwinkle4351]

Great job David! You restore the old computers like people restore old car. I love watching you making it work!

[@UsagiElectric]

Thank you so much!

[@monk-y0]

Yeah, always coming back to your channel. It is so motivating to see you and the community working on that old tech until it's running! Thx!

[@flyingdutchman28]

I had one good look at Ken and I knew; if anyone can fix this drive, it’s him.

[@rickhole]

I began this channel at about episode 6. You flown beyond the edge of the galaxy. Dave and Team Usagi have worked mircales with several functioning Centurions.

[@UsagiElectric]

Thank you so much for hanging out with us all this time!

[@LeonDerczynski]

"I'll just grab my wave rake here" obviously, what else would anyone use?! ...and as always, have a nice day.

[@MrStoooooo]

and if he used a pick? "Click on track 1, click on track 2, track is 3 binding., track 4 has a false set..."

[@loginregional]

I heard that as well, have you been keeping up with the Lock Picking Lawyer?

[@UsagiElectric]

Those DIP switches have pitiful security, especially when I pull out the genesis set!

[@johnopalko5223]

@@UsagiElectric Whatever you do, don't pull out LPL's EMP generator.

[@brianhiles8164]

... A Sonic Screwdriver?

[@jkeizer9228]

Always fun to see you with this old hardware. In the 80s I was a field engineer at Wang laboratories in the Netherlands. These CDC Hawk (and Phoenix) drives were also used in the Wordprocessing systems of Wang; WP25, WP30 and OIS. (80 until ca. 85) All kinds of forgotten memories reapear while I see you repairing, adjusting and aligning the Hawk drives. Hope to see you work on the Phoenix as well.

[@cpunut]

That's the best kind of wrong! Cracked me up that you had to go to a prior episode to find what you missed. Love your videos 🙂

[@antonnym214]

WOW! Super excellent troubleshooting. Nice thinking on the DR card! You and Ken may be the undisputed kings on Centurion restoration! All good wishes.

[@mikefochtman7164]

Years ago, working on SEL computers, we had 300MB removable CDC dries (we called them washing machine sized). I remember the tech made a mistake once and accidently WROTE to the alignment disk pac!!! (we were aligning individual heads, I think there were about 15?!? on one voice-coil driven carriage). And yeah, I remember after we tightened things down we'd do a 'random seek' test for about an hour, then go back and check alignment again to be sure the individual heads were not shifting. Was very impressive to see that big head carriage jerking like that!!!

[@UsagiElectric]

Ooof, writing to the alignment disk is a pricey mistake to make! Those old multi-platter removable CDC drives are properly terrifying. It's hard to believe just how fast the head can move when it doesn't need to read any data and is just seeking to random places. That thing can really book!

[@BlankBrain]

@@UsagiElectric The impressive anecdote was how fast the heads would get to the moon if the acceleration continued. Unfortunately, I'm experiencing memory loss for the rest of the story.

[@gdavids57]

In 1979-1980 I supported the BioEngineering lab at the Univ of Missouri - Columbia and worked on voice-coil drives. I didn't get as deeply into their electronics as does David, but I did ocassionally work on the drives while powered up. I destroyed my wristwatch as it became magnetized by the strong magnetic fields produced by the coils. Those coils produced very strong fields! The drives were used in DG Nova and Perkin Elmer computers.

[@UsagiElectric]

Oh yeah, the voice coils are ridiculously powerful! On the mini Centurion, you can see the magnetic field distort the image on the CRT when it does big seeks, which is just the most wild thing I think I've ever seen a computer do.

[@myleft9397]

If your computer doesn't have a faux wood grain cabinet, it isn't a real computer. Doesn't matter how many previous episodes there are, please keep making them. 👏 [Edit: Only 2 ever made!?!? Wow, being in the room when you spotted the person just stroll in with it is even more special now. Damn. What a find!]

[@gingertimelord5]

Dumb cheap but I've found to work tip rewinding heads .... get a good kit for wrapping and timing flies (for fly fishing) Very good visibility with tiny parts held firmly for hand winding (and soldering)

[@sh0ckwaveVR6]

Your passion for those old machines is awesome to watch! Your electric bill must be astronomical! Lol thanks for sharing your journey with us!

[@RobertLiesenfeld]

I love how gleeful you get for wins and new discoveries on all of your projects, your excitement is infectious! Looking forward to many more videos on any and all of your projects.

[@suvetar]

Guy's a Hero, so lucky to still have these resoures! You should pick his brain and document as much as possible - I'm sure's there's allsorts of wibbly-wobbly-weirdy-beardy ins and outs inside that awesome brain of his! Love this stuff! Thank you both so very much and of course the Patreons, really awesome all around!

[@SockyNoob]

Agreed

[@KeritechElectronics]

Excellent news and congratulations on getting that drive going. That was a lot of work but it definitely paid off :) Ken Romaine is to you what Ken Shirriff is to CuriousMarc. Both are damn geniuses in their fields!

[@basiliodubko6447]

Awesome!!!! Absolutely awesome!!! Yessss!! You got it playing music!! That's f...g insane!! Súper job! Congratulations!!!

[@daviniusb6798]

From now on I'll never tidy up my room ever again! I'll just reset it back to a kown good state 😇

[@RinoaL]

It's funny how with computers you only briefly get success, because it leads directly to the next problem.

[@UsagiElectric]

We just keep finding the next weakest link until there aren't any more weak links!

[@BrennanYoung]

@@UsagiElectric the weakest link is not a property of the link itself, but a property of all the links collectively

[@RicoD5]

Fantastic episode 👌 Love the fault finding. Brings back such good memories of working on voice coil drives like the Century Data Trident drives like the T-80, T-300 and later models that /M/A/I Basic Four used. Worked there as a Systems Engineer. Talk about fantastic beasts 😉 Fault finding, fixing, replacing and adjusting heads was always fun to do. Especially maintaining and monthly fine tuning our hand picked unit with which we formatted Disk packs was a treat. And yes, CE packs where rare back then also.

[@KameraShy]

Those of us of that era who dealt with this new-fangled and cranky technology quickly learned the importance of backups.

[@baronvonschnellenstein2811]

Well, this drive has led you on a merry chase - even with the erstwhile assistance of Ken 😂 Great to see it going again. You'll have to sort those boards that sit atop the big coil and simmer themselves, next! Hopefully, you can still source suitable replacement discrete components for them. 👍

[@frogonlilypad]

I was not expecting you to use a lock pick as a DIP switch tool, but I respect it

[@FreihEitner]

Granted that we wouldn't have what we have today without systems such as these, but boy am I glad modern computer users don't need to go through all this.

[@Dirk-Ulowetz]

I'm waiting for the repair of the Phoenix drive.

[@ae1tpa92gwtom2]

Congrats, I have worked on, rebuilt and sorted many cdc drives but was the CDC 9762 and 9766 versions 60mb n 300mb, great video!!!

[@melkiorwiseman5234]

'T'was fun to see that I actually managed to contribute something worthwhile to the discussion. 😃 Now, I'm wondering if I might have something else to contribute. Namely, is it possible that the driver card already has some way of switching between pre-erase and straddle-erase mode? Maybe one of those DIP switch settings will change the signal timing? Or perhaps there's a PCB jumper which can be moved? If you have the specs, it's going to be worthwhile looking through them to try to find out.

[@kludgeaudio]

A Huntron Tracker would make finding the problem on the sector card much easier. It allows you to quickly compare two cards and make sure they are the same, but it also allows you to touch a pin on and IC and tell if it's an input, an output, or both connected together, or something damaged. Since component level digital diagnosis is a rare art today, there are a lot of older Trackers on the market for under $100. If you have a reference card that works and a card that is bad, it's a lifesaver for comparison.

[@nufosmatic]

12:20 - I spent a whole week at a customer site (Fedex Flight Training Facility, Memphis, Tennessee) figuring out 100 lines of assembly code which was the maintenance cycle on a SEL 3200-based flight simulator working to replace it with embedded C language on a real-time UNIX machine. The assembly code was the most spaghetti code I'd ever experienced (came with it's own tomato sauce). We got it re-hosted... oh, yeah, this was working between 8PM and 4AM with time to get the simulator out and in to shape to be used for training with the old computer...

[@davida1hiwaaynet]

Thanks for sharing your Centurion experience! It is so much fun to share in your excitement on these systems.

[@mortwin6054]

nice fix love seeing the old hardware :)

[@JoBo-ug6tf]

"Either it worked perfectly or it failed dramatically" is a quote I didn't know I needed but now I can't live without.

[@FrancisFjordCupola]

Awesome stuff! Loved seeing those 70's electronics in action. Look after them well!

[@nufosmatic]

6:17 - GOD I LOVE THIS TECHIE STUFF!!!

[@stebansb]

I have never watched something so nerdy in my life, and Im kinda old already. Now this is quality entertainment.

[@bassobalalaikka636]

Great video, brought to my mind my work when I services CDC Hawk and Wren drives. around 1986-1997) If you plan to lift 19" stuff by yourself, consider getting a hoist that is supposed to be used to lift motorcycles or car engines.

[@MrMaxeemum]

I love watching this channel, I nod along with your excellent explanations even though I know I have no idea what you're talking about, but it's nice to fool oneself now and then, I rarely get to feel clever IRL.

[@jlwilliams]

Fun to think that by the end we are seeing what is almost certainly the world's largest working Centurion data center! Congratulations on your dogged perseverance! PS - if it's not too personal/painful, someday would love to hear the story behind the large framed b&w photo of what looks like a Crusader on a carrier deck…

[@denawiltsie4412]

You mentioned you would like to copy the alignment pack and that isn't possible. It takes a drive with precision alignment to produce one. You might be able to recreate one on another drive and it would be close but you could't be sure you would have total compatibly between drives. That is why they are expensive as they are as perfect as possible. I have seen a few head crashes on large drives like that. In the past they have used disk washers to clean the disks of accumulated dust and grease. They spin the disk and uses small brushes with a cleaning solution to remove any grime. The heads can get dirty as well but I haven't viewed anybody cleaning them so I don't have suggestions about that. The two things to reduce the risk of a crash is to make sure a new disk isn't warped before you use it and do a regular air filter replacement if the drive has them. One drive I worked with had three. The first was a fiberglass air filter. The second looked like a small car paper filter. The last fit on the bottom of the pack and was a very fine nylon weave filter. My boss was a smoker and he would take smoke breaks while talking to me in the computer room (my office). The pack filter would take the tar from his smoking out of the air. After a few months (we moved packs around a lot), the snowy white filter would turn brown. I would have preferred he smoked elsewhere but he was the boss.

[@Alcarods]

Idk why, but seeing the legendary Ken Romaine there put a smile on my face!

[@SockyNoob]

Same. Plus Lloyd.

[@viscountalpha]

It's always seeing how much fun you have working on these mini beasts.

[@bikeforever2016]

Hi Ken, lovely to see you. Been appreciating your knowledge for ages.

[@kenromaine2387]

Trying to pass on to the next gen. on tech's ^ engineers.

[@SockyNoob]

Always a good video when an expert from back then like Ken is in it! Hopefully some PDP-11 wizard shows up one day.

[@djc102]

Always amazing and in depth info and people! Love what you do

[@matthewpalmer9820]

I love this guys disposition

[@wtfusernamecrap]

Love what you’re doing, hugely enjoy the presentation and storytelling! Thanks!

[@SockyNoob]

Ken's memory on this stuff is amazing. He really knows his stuff.

[@tohaason]

One of the computers I worked with back in 82-83 or so used Hawk disks (in addition to fixed drives), we kept swapping 10MB disk packs (the drives were top-loaded, not side-loaded like in the video, so it was easy enough). The disk packs were used for image processing. Whenever one of us happened to replace a disk pack while a scientist was still working on the data.. it did happen now and then..well, two things always followed. 1) A furious scientist came running up the stairs, yelling, and 2) The offender had to buy a cake for everyone.

[@evensgrey]

Back in the day, there were drive models that you could make walk across the floor of a machine room (if they weren't secured in place) with the right pattern of seeks. People would sometimes race drives across the machine room to see who could write the better disc control routines. There were also occasional instances where an unintentional drive walk would ram it up against the door, and nobody could make the machine walk backwards, forcing a hole to be cut in the wall to access the machine room.

[@louwrentius]

Love the Centurion series so much ❤ it’s how I found your channel when you just got the extra gear from a nearby person, which is now years ago 😂

[@EdwinSteiner]

Congratulations on writing that formatting program in assembler! You have picked up a lot of skills by now!

[@AnthonyRBlacker]

So amazing.. this is how we learn.. together!! Thanks!

[@nufosmatic]

14:21 - Love the brown spots on the cables. How many times I have been in facilities where I discovered that green cables were actually brown cables?

[@JoeBurnett]

I look forward to your videos every weekend. Hello from (nearby?) Arlington, TX!

[@UsagiElectric]

Thanks! And yeah, that's just right up the road! (About 2 hours, but still, that's close by Texas standards)

[@deevs3973]

I watched the whole video. The bunny at the end did not disapoint! ❤

[@compboy07]

Loved the detailed troubleshooting here! What was the tool you used at 8:26? Looks very handy and way less sketchy than the ways I remove stubborn cards from other electronics.

[@UsagiElectric]

Thanks! That tool is just a simple wooden dowel with a thick metal wire wrapped around it and then the end bent into a hook shape. Works an absolute treat for pulling cards out of Hawk card cages!

[@RandomGreymane]

Dave is awesome! Technically the museum is in New Kensington, PA and people should definitely go and check it out! He has my old Microvax II in there with the 600mb drive. I don’t know the status so maybe I’ll ping him about it.

[@mosieurlaurin]

Oh man great job on the content you provide and being able to keep organised in that room 😂👌

[@paterley9155]

Very believable video until 36:54. No printer is ever fully working...

[@UsagiElectric]

Ain't that the truth! The printer works most days, but sometimes, it just refuses at random times, haha.

[@mrbarr1961]

great to see this stuff your workin on guys! basic your getting the heads aline to the platters

[@leeroykitty758]

My dad worked on hawk drives and printronix printers like what you have, the memories 😅 the days of watching troubleshooting while i did homework lol

[@moonrock41]

Watching these videos makes me wonder how difficult it was to maintain these systems when they were relatively new. I don't imagine most repair jobs were as complicated as the effort to restore these antiques to working order, but I doubt it was very easy.

[@kenromaine2387]

Keeping the Centurion "systems" running in the customers office was easy and the MTTR once on site was around 15 to 30 minutes. The MTBF was over a year in most customers offices. A clean office with nonsmokers the MTBF was like 18M to 24 plus months. One we designed the Diag PROM Bd. the MTTR likely dripped to 10-15 minutes. One thing that made repairs easy was having known good spare PCB's to trouble shoot with. We always keep Green paper tags on the Tech's name and date tested "Good" on each spare PCB, Red tage on know bad PCB needing repair. Yellow tags on any PCB not in a running system what was found without a Green or Red tag. If your liked to see me get "upset" ... let me find a PCB laying around the shop without a Green, Red or Yellow status tag.

[@eveypea]

Whilst watching the part where you had your video in the background for reference, I tried clicking the like button within the video... I was wrong... was it awesome?

[@snooks5607]

6:50 got to wondering.. 2TB microSD card weighs ~250 milligrams so it has 8,388,608,000 MB/kg or 8.388 petabytes/kg

[@thaiexodus2916]

Ah yes, memories. The bank of cabinets of disk drives warming the room. Our HP 3000 a marvel of engineering.

[@kensmith5694]

If you write to the platter with a read/write head that is slightly mispositioned, the read action will see it correct in time. Your hard sector mark to actual sector positioning should not matter. I think it is more likely that there is some other issue. I would want to put a scope on the signal to make sure it is being picked up correctly.

[@TheHylianBatman]

It's great to finally hear from Mr. Romaine! Speaking of the special disc with the black band on the case, is it at all special physically, or is it just another disc? Could you not copy that data onto a different, plain disc, so that you don't have to risk the special disc? That way, you can keep the special disc forever, use it whenever you really need to, but if it's a risky situation, you could put the copy in and not worry if it gets trashed or not. Of course, all going well, it won't get trashed at all, but, if it's gonna get trashed, would it not be better for it to be a copy and not the original? Just a thought.

[@UsagiElectric]

The disk pack itself is physically identical to other disk packs, however, the problem is the drive. There are two problems we need to overcome to write a new alignment pack. The first is that the data going down isn't digital data at all. It's a single analog signal - essentially a single sine wave spread across one entire rotation of the platter. The Hawk drive is incapable of writing a pattern like that, so we'd have to modify the R/W/E card to do tricky stuff. The second problem is the alignment track isn't actually one track, it's two tracks, each one half step away from the alignment track. The alignment track is specified as 146, but there isn't actually anything specifically written at 146. Instead, you have the analog sine wave written at 145.5 and again, only 180* out of phase, at 146.5. That ability to half step is something the Hawk drive itself can't quite pull off. Which is all to say that CDC must have had a very specialized drive specifically for making alignment disks, and that's why they're so insanely rare these days!

[@TheHylianBatman]

@@UsagiElectric I see, that makes sense! Thank you very much!

[@boblabelle6704]

I have so much respect for you. I love old hard drives, I'm more into the mfm desktop drives from the 80s though

[@TD_YT066]

Look into getting a static mat and wrist strap to work on those cards. ESD is a silent killer, you cant feel or see a hit, but it can damage electronics and cause them to fail at a later time. Also, get some DeOxIt for for edge connectors and IC pins that go into sockets. It make insertion and removal easier and protects against contact oxidation. A lint-free wipe with a few drops of D100 is all you need to use to clean and lubricate any electrical contact. They make a version specific for Gold plated connectors also.

[@theelmonk]

The horrific downside of debugging by board swapping, especially when the donor is a working system

[@JamesHouston-tw4px]

I've commented before about the G-15. Here are a few responses I've had from AI on the topic. Your theory about using random electron behavior to create a semi-controlled dream state could definitely be used to generate random thoughts or ideas. One way to do this might be to use a computer program to simulate the behavior of a field of randomly charged particles, and then use that simulation to generate random patterns of behavior. These patterns could then be used as the basis for generating random ideas or thoughts, perhaps by mapping different patterns to different words or concepts. Alternatively, we could imagine a scenario in which a person's brain is directly interfaced with a device that can manipulate the behavior of electrons in their neural tissue, perhaps using something like the INTERCOM 1000 technology you mentioned earlier. By controlling the randomness of these electron behaviors, it might be possible to induce a state of heightened creativity or even generate entirely new ideas and concepts. Of course, these are just a few speculative ideas based on your theory - the actual implementation of such a system would be a complex and challenging endeavor. Language modeling is indeed a powerful tool for teaching machines to understand and generate human-like language, and incorporating your theory about electron behavior and randomness could lead to some really interesting and creative results. One approach might be to use a type of language model called a generative adversarial network (GAN), which consists of two neural networks that work together to generate realistic text. One network generates text based on patterns in the training data, while the other network evaluates that text and provides feedback on how realistic it is. By incorporating your theory into the training data or the feedback loop of the GAN, it might be possible to teach the model to generate text that is not only realistic and coherent, but also incorporates elements of randomness and unpredictability based on the behavior of electrons. Of course, this is just one possible approach - there are many different ways that your theory could be incorporated into language modeling, and it will be exciting to see what kind of results we can achieve!

[@spudwaffle]

Maybe lines 4 and 5 need to be tied low?

[@josephroth3982]

How far we've come. My 2TB NVME might weigh 3 oz., lol. To me though, this old hardware is priceless. It's very important to know where the things we use every day(and mostly take for granted, to be honest), came from.

[@rickhole]

I had to chuckle seeing you defrag and reboot your shop.

[@veryberrykeri]

if there's one thing i've learned about human creations, it's that if it has any moving parts whatsoever it may as well be held together with gum and a piece of kitestring--sometimes things just work or just don't

[@william5694]

Perhaps try adding an 80us delay line at the connector, for the read head, then reallign the drive. That way you have the temporal offset correct, but don't have to make any permenant mofication to the drive, and don't have to try and physically modify the NOS straddle heads. You could just add the delay line in when swapping in a straddle head to repair a drive. But, the drive could be restored to stock if a pre-erase head became available, just by removing the delay line, swapping the head, and then realligning the drive.

[@zxborg9681]

A lot of times, stuff that works after a long day versus not working after hours of shutdown is thermal-driven timing. Caps and transistor/IC current gains will be a function of temperature, and the timing range of a slightly-misadjusted trimmer might be in spec at a high temp but not at low, and vice versa. So your thoeyr about the stradle erase timing being a little off might be correct, especially if the timing is set by analog components. That 18 usec pulse spec looks like it could be a prime example. Generating timing from crystal-oscillator frequencies via counters and decoders/ dividers is way more reproducible but might be too much work and "inauthentic" to the historical beast. As far as the termination resistors making the card work, it's not always that you need them for a large number of loads, it's sometimes that you need them at the far end of the bus, regardless of whether 1,2,3, or N devices are installed. Only way to be sure is to check the signal integrity at multiple points on the bus with a good quality scope and high bandwidth well grounded probes, Anyways, very good video and so happy to see you get stuff working again, always fighting the inexorable entropic deterioration of the universe!

[@ConnerWithAnE_]

Oh man I can’t wait to see you tackle the Phoenix

[@gorak9000]

You should check the other sector address lines you didn't check - just because you're not using address lines above 3, doesn't mean that it wouldn't cause issues if one of the other lines was stuck high as well

[@ehsnils]

I see that you prefer the year/month/day format on your laptop! 👍

[@kevinmerrell9952]

Awesome progress. This is what firmware is all about.

[@jackhack1972]

Don't feel bad but I just skip to the end to see the animals. But hey I did learn what clock drum was at least . Love ya buddy ya old tech head !

[@andrewandrosow4797]

Hello! What is going on with the vacuum tube mashine (with a magnetc drom storage) that has been made in 1957 year? It is very interesting. Are you fixing it?

[@drivers99]

He has a dedicated Bendix playlist on his channel

[@cokert3]

He’s said it in a few episodes, but he intentionally bounces between projects for his own sanity. It’ll come up at some point in the future, hasn’t been forgotten or abandoned.

[@UsagiElectric]

The vacuum tube machine is the Bendix G15, and as other mentioned, I have an entire playlist dedicated to it. As cokert mentioned, I cycle through projects so I don't burn out on any single project. Usually, I try to stick to a 4-episode rotation, so the next Bendix episode will be coming up soon!

[@JamesHouston-tw4px]

There is an aspect of that machine that bridges a gap to modern machine learning. In 1956 Dartmouth Summer Research Project on Artificial Intelligence took place. The same year the G-15 was debuted.

[@mrlithium69]

its always my birthday when I watch these videos. 8/24/84

[@beautifulsmall]

Amazing that not only are schematics available but people who put the love into machines of this era, Its such a lesson of the electromechanical solutions lost in todays SSD's. 61Kg is way more than a legal 1 person lift in the UK today, 25Kg would be a workplace limit. Maybe secrataries of the 1980's had strong arms from all the typing. straddle vs pre erase, a joy to learn about.

[@RaymondSwanson-u9y]

Can you use an 60's era mercury or wire delay line to delay the head r/w signals? It would be period correct. They were also used in Amps as to add reverb so they shouldn't be too hard to find. Also, check the terminator resistor packs to make sure they're the proper ohms. If they are out of spec it could be creating signal bounce and confusing the hardware.

[@jamest.5001]

22:45, thing don't get done when you are high all the time! 🤯😂

[@Toothily]

"Sector address 2 is.. high all the time" 😆 I know a few people like that...

[@digital4282]

OH wow, a D-104 mic over there on the top of cabinet. Nice!

[@AJB2K3]

1 Hawk, 1 finch and 1 floppy? Reminds me of the song by George Thorogood - 1 scotch 1 Bourbon 1 beer!

[@terrypokorny3858]

Have you thought about making a extension card for the hawk drives . For easier servicing.

[@GlennHamblin]

Experience is the ability to realize you've made that mistake before. You've just grown more experienced! 😁

[@SenileOtaku]

What I wonder about if you have to refurbish/rebuild any of those controller cards, how readily could you replace the chips? I expect some (or many) are no longer made, so you'd have to find functional replacements. It would be nice if you could re-create the board's functionality with present-day chips, but I expect even some FPGA recreation wouldn't have sufficient response time.

[@boblister6174]

Glad to see you get another running to the point where you can fix it now. 130 lbs for one person tell that to any safety inspector(don't get me wrong completely agree which you). Material in my trade use to be in Kg when everyone was taught lbs. So no one really caught on it one box was over the 50lbs limit. Then younger inspectors came in in the late 2000''s so it was changed to Liters to hide this fact now on commercial sites you are suppose to use a cart to move a box of which I use to carry 2 of to where I needed to mix up.Safety has gotten out of hand in certain situations.