Usagi ElectricFirst things first, Open House at System Source Museum! Date and Time: October 23, 2023, 1500 - 1900 Location: System Source Museum, 338 Clubhouse Rd. Hunt Valley, MD 21031 Link: museum.syssrc.com
We may have lost the battle in the previous episode, but we sure as heck aint gonna lose the war! In this episode, we dive in deep on the power supply. It’s a weird one too – a ferroresonant supply. No, I didn’t just make that word up, it’s a real thing, I promise! So, let’s find out just what that is, and then let’s dig into the supply itself and find out just what exactly went wrong.
Chapters 0:00 Open House at System Source Museum! 1:29 Where did we leave off? 3:52 First things first, what is a Ferroresonant power supply? 5:45 Let’s start with a regular transformer 7:51 Both feet first into the deep end with Ferroresonant transformers 12:29 Once we got our stable AC, then what? 13:45 What went wrong on our power supply? 16:04 Zeroing in on the issue 18:19 A full day later… 23:13 Victory! 24:17 Begin rant 25:55 End rant 26:22 Putting it all back together 28:27 The final test! 32:11 Bunny!
Ferroresonant Transformers and Making the Centurion Complete!Usagi Electric2023-10-08 | First things first, Open House at System Source Museum! Date and Time: October 23, 2023, 1500 - 1900 Location: System Source Museum, 338 Clubhouse Rd. Hunt Valley, MD 21031 Link: museum.syssrc.com
We may have lost the battle in the previous episode, but we sure as heck aint gonna lose the war! In this episode, we dive in deep on the power supply. It’s a weird one too – a ferroresonant supply. No, I didn’t just make that word up, it’s a real thing, I promise! So, let’s find out just what that is, and then let’s dig into the supply itself and find out just what exactly went wrong.
Chapters 0:00 Open House at System Source Museum! 1:29 Where did we leave off? 3:52 First things first, what is a Ferroresonant power supply? 5:45 Let’s start with a regular transformer 7:51 Both feet first into the deep end with Ferroresonant transformers 12:29 Once we got our stable AC, then what? 13:45 What went wrong on our power supply? 16:04 Zeroing in on the issue 18:19 A full day later… 23:13 Victory! 24:17 Begin rant 25:55 End rant 26:22 Putting it all back together 28:27 The final test! 32:11 Bunny!Testing Thousands of G15 Germanium DiodesUsagi Electric2024-10-13 | I can’t fault them, they’re nearing 70 years old, and that’s a big ask from diodes that old! Still, we know for a fact that we have at least two bad diodes, and I suspect we may have dozens more. Which means, it’s time to test diodes. But when the machine has more than 3,000 diodes lurking inside of it, how do you test that many without losing your mind? Well, turns out, Bendix made a pretty awesome little tester to do just that!
Chapters 0:00 What does 80 million yen buy you these days? 3:54 A problem of scale 7:16 A walkthrough of the tester 12:10 Calibration (if you can call it that) 13:57 Test drive time 16:56 Time to test 3,000+ diodes 18:51 This never happens, I swear! 21:50 Surely, I didn’t make it worse, right? Right? 23:40 Legitimately took me 5 hours to hunt down the fault… 26:53 Bunny is upset there’s no more bananaThe Bendix G15 Boots!Usagi Electric2024-10-06 | We did it! We did it! We did it! Kind of… It boots, and let me tell you, it was an absolute journey to get it to that point. But, it’s still not quite right. It’s trying to execute code, it’s just executing the wrong code. Still, with multiple bad germanium diodes and even a bad photodiode holding us up, it was an absolute battle to get to this point. But man alive was it worth it!
Chapters 0:00 Who let me get my hands on a piece of history? 3:10 Cleaning the dirty motors 6:32 Giving them a test 7:10 Photodiode problems 9:26 Maybe it’s dirty potentiometers? 11:20 Nope. Okay, let’s learn how the phototape reader works 16:16 Bad photodiode. What next? 18:52 Did that fix it? 20:24 Not yet. Okay, let’s learn how the input system works 23:59 Troubleshooting montage! 32:46 Yoooo, that’s a booted machine! 35:22 Banana time!A Day of Fun With MFM Hard Drives!Usagi Electric2024-09-29 | Usually, I rotate through about four big projects, but lately, I’ve been falling behind with some basic housekeeping around the shop, so today, let’s do some of that housekeeping. I’ve been amassing MFM drives for about a year now, and it’s finally time to take them out, and see which ones work and which ones don’t. So, let’s bust out the Gesswein MFM Emulator and a screwdriver and make some questionable decisions!
Come hang out with us at the LSSM on October 25th: https://lssmuseum.square.site/product/haunted-hardware-fundraiser-ticket-patron-access/1
Chapters 0:00 A day of housekeeping 3:15 How to use the Gesswein MFM emulator 8:46 Speedrunning time 11:20 Programmers make better lovers 16:03 The CDC Wren 19:01 The CDC Wren II 21:22 The Quantum RD52 25:39 The Seagate ST4097 28:04 A little bit of failure management 30:59 Turning a 10-minute job into a 2-day job 33:16 Baby bunny!Restoring a Model 15 and a Model 14 TeletypeUsagi Electric2024-09-22 | I love teletypes, which might seem like a weird thing for a vintage computing dude to say, but really, teletypes are just electromechanical data terminals! The communication protocol is a little different, and of course you’d have to match speeds, but it receives serial data and transmits serial data, it just does it with motors and contacts and spinny bits. And that makes them awesome.
Chapters 0:00 A wild John appears 4:13 Disassembly 6:03 We found the current loop! 6:26 Cleaning 8:29 A very sad dashpot 11:17 Back to cleaning 12:13 What even is a teletype though? 14:01 How to send 17:15 How to receive 21:29 Final assembly 22:14 An oil bath 23:28 Checking the RPM 25:20 First test 26:08 Victory! 27:45 But wait, there’s more! 30:38 An oil bath… again 31:23 It took a while, but we got there 34:20 A gift for John 36:40 Baby bunny!VTC P.38 – I Built a Paper Tape Reader from Scratch!Usagi Electric2024-09-15 | This is it, this is the first real step towards completing the project! And boy what a step, because we step right out of our comfort zone, and right into machining and manufacturing. You can see in the thumbnail that some successful machining took place, but it wasn’t without its frustrations for sure. This is a fun one y’all, so tag along as turn big pieces of aluminum into small pieces of aluminum.
Chapters 0:00 This is a big version of this 2:02 What madness have I built? 6:33 What madness will I build today? 8:15 Aluminum fears me, as it should 16:18 What madness did I build? 20:22 What madness will I build next? 23:40 No madness, just fluffy bunnyThe Most Adorable Data Terminal Ever!Usagi Electric2024-09-08 | Hi, I’m sick. Hi, Sick, I’m Dad. No, literally, I’ve got some kind of upper respiratory thing going on and it’s no fun. I am coming out the other side of it, however, when you’re loopy and contagious, there are certain things you shouldn’t do, like invite people over or play with heavy machinery. So, today, we’re taking a bit of a break to take a look at an adorable little data terminal BoxcarJim donated!
Chapters 0:00 “Get up, come on get down with the sickness” 3:14 “I’m adorable and I know it” 6:46 “Whatcha gon' do with all those ports, all those ports inside your trunk?” 7:57 “It’s getting’ hot in here, so take off all your… CRTs?” 8:48 “The Devil went down to Texas Instruments” 11:26 “What does the Quick Brown Fox say?” “’Hellorld!’ obviously.” 12:37 “No phone, No phone, I just want to be alone today” 16:29 “That’s why I say, ‘Hey man, nice terminal. What a good terminal man.’” 17:18 “Just like the fat orange cat, sings a song, sounds like he's singing”
For the curious: Disturbed, LMFAO, Black Eyed Peas, Nelly, The Charlie Daniels Band, Ylvis, Cake, Filter, Stevie NicksSolving the halting problem with my PDP-11/44!Usagi Electric2024-09-01 | In the previous episode, we got the 11/44 up and running, and it looked like it was trying to go, but we kept running into a problem: we couldn’t halt the CPU. Which seems like a really weird thing to want to try to do, but PDP gonna PDP. At any rate, we need to get the CPU to halt so we can start trying to run stuff on it, as counterintuitive as that sounds. So, today, that’s what we’re going to tackle!
Chapters 0:00 Solving the unsolvable 1:16 Solving the real halting problem 3:51 Taking care of the basics first 6:26 A little board swap and some progress! 8:40 Getting some help from the past 11:25 An introduction to PDP11GUI 14:22 Loading something from a simulated paper tape 18:02 The two avenues of media 21:28 Slow motion noms!I Was Wrong… and It’s Awesome!Usagi Electric2024-08-25 | You guys called me out on it, and you know what, y’all were absolutely right! My understanding of straddle erase versus pre erase was definitely flawed, and I’m so glad you all spoke up about it. This particular drive came from the amazing Dave McGuire over at the Large Scale Systems Museum (mact.io) up in Pittsburgh, and in the previous episode, we didn’t get it going. Can we get it going in this episode? Well, at 40+ minutes, I bloody hope so!
Chapters 0:00 At this point, I still didn’t think I was wrong… 3:04 The man, the myth, the legend, Mr. Ken Romaine! 6:41 Start with the basics 9:30 Okay, let’s try putting data down again 11:59 A short interlude on why my program failed 13:50 Back to troubleshooting! 16:57 Success! 18:34 What went wrong? 20:04 Searching for a missing Sector Address line 25:09 That fixed it, right? Right? 26:42 Oof 28:11 Success again! 30:50 And introducing, special guest star, my underwear! 32:20 What happened to the mini Centurion? 37:09 We still got problems, naturally… 41:27 Nom nom nomVTC P.37 – Learning How to Build a Paper Tape Reader!Usagi Electric2024-08-18 | The one-bit vacuum tube computer is back baby! Well, kind of. The reason it’s been so long since we last took a look at it is because I’ve been doing some serious thinking about how best to build the paper tape. I experimented with a lot of ideas before finally settling on a “Keep It Simple Stupid,” approach. Fair warning, this episode is primarily to get everyone back up to speed on the project and let y’all know what direction we’re now headed in for the paper tape. The good news is, we have a gameplan, so things should start shaping up real soon!
Chapters 0:00 This is almost a computer 1:19 First things first 3:12 Where are we on this thing? 6:23 Just missing a paper tape reader 7:45 What is paper tape even? 9:10 How are we going to read paper tape? 10:27 Idea 1: Mechanical followers 12:21 We need to take a book out of everybody else’s page… 12:52 “Time to go mobile” 14:14 Idea 2: Optical but with big boy photodetectors 16:35 Idea 3: Nipkow disc? 17:32 Idea 4: 5mm photodiodes 19:26 This all seems way too complex, how did Bendix do it? 20:05 Idea 5: This is the one 21:49 Giving the concept a test 24:11 Ideas on how to demonstrate the machine 25:53 30 seconds of bunny nomsThe Bendix G15 Inches Closer and Closer to Booting!Usagi Electric2024-08-11 | The G15 wants to run, I can feel it, but there’s just a few things holding us up. The typewriter is giving us the run around, so first order of business is sorting that out. But in the process, we find all sorts of weird modifications to the typewriter, and then we run into even more troubles with the paper tape reader. But, progress is progress and we’re getting closer and closer to fully booting up!
Chapters 0:00 Who let me get my hands on a piece of history? 1:03 What stopped us last time? 2:30 Why didn’t I just jumper the SA line to -20V? 4:10 I can’t make sense of these mods, can you? 5:58 Where did my 0Va, 0Vb and -20V go? 8:48 A quick fix to get us up and going 10:17 Did that fix it? 12:40 Nope, try again! 14:56 Serious progress! But why isn’t it reading? 18:51 Let’s take one last swing at this 19:55 The paper tape reader is going to need some proper effort 22:22 Sunny kun!I Repaired This 1970’s Hard Drive, but I Still Can’t Use ItUsagi Electric2024-08-04 | It’s no secret that I’m a huge fan of spinning rust, and so I’m always going to jump on an opportunity to work on my all time favorite hard drive, the CDC Hawk. This particular drive came from the amazing Dave McGuire over at the Large Scale Systems Museum (mact.io) up in Pittsburgh. But, this Hawk Drive is a Straddle-Erase instead of the Pre-Erase I need. What does that mean? Well, that’s what the video is for!
Chapters 0:00 This is my forever computer 3:40 Welcome to the CDC Hawk Drive 8:09 Let’s take this thing apart 9:30 Head crashes! 12:34 Head coils 14:09 Straddle erase and pre-erase, an introduction 16:29 Cleaning and rebuilding 19:51 Loading the heads and test drive 23:25 So, why can’t I use straddle erase heads? 28:55 Slow motion noms!An Epic Trip Through Japan!Usagi Electric2024-07-28 | And now for something completely different. I’ve been going pretty hard at work lately, so it was time for a little time off, and what better way than to hop on a plane for the most wildly perfect country in the world. Hop on along with us as we see some historically significant computers, do some pretty righteous thrifting, and go on a road trip through the most beautiful countryside you’ll ever see.
All other music from: Artist: Ben Prunty Album: Chromatic T-Rex
Thanks for watching!
Chapters 0:00 Time to Relax 0:35 Welcome to Japan! 1:29 Heavy metal at the Tokyo University of Science 2:42 The Bendix G-15 5:20 The Facom 201 (and some terrible audio) 7:56 The Univac 120 9:46 A small retro computer get-together 10:40 Sean’s Multi8 11:29 Curt’s TK85 12:29 Tom’s MSX 13:23 Sven’s custom adapter 14:06 Michelle’s NEC PC-9801 14:50 A little thrifting montage 19:29 My haul 22:05 Makidou Caves 22:40 Bihoku Circuit 24:27 Okayama Omurice 24:52 Kurashiki Bikan 25:38 Fukuyama Auto and Clock Museum 27:25 Matsuyama City 28:21 Oda Miyama Gorge 29:24 Nakatsu Gorge 30:13 Awajishima Monkey Center 31:28 Nara Park 33:07 Sunny kun!The PDP-11/44 Lives!Usagi Electric2024-07-14 | The PDP-11/44 power supply has been giving us the proper run around, but I’m too stubborn and dumb to know when to quit, so we’re right back in the thick of it in this episode. Only this time, I come out of the gates swinging and emerge victorious! Sometimes, not knowing when to quit is a good thing. Once we got all the power rails up, it was still a bit of a challenge to get proper life out of it, but we got there for sure!
Chapters 0:00 This is the last intro I’ll film about a dead power supply 2:25 Could it be just a fuse? 4:53 Running down the wrong path 6:56 Finding the right path 12:00 Victory! 13:59 The cards 18:55 Trying to power it fully up 22:09 Life! 24:50 What’s next? 26:38 Ten chan!The Bendix G15 (Almost) Roars into Life!Usagi Electric2024-07-07 | 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!
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!PDP-11/44 PSU is Slowly Coming Back to Life!Usagi Electric2024-06-30 | This PDP-11/44 power supply is taking me to school, but we’re slowly getting there. In this episode we dive in, make some mistakes, repair our mistakes, and then make a little progress. Actually, I have no idea how many people actually read these descriptions. If you do, you’re a rockstar!
Chapters 0:00 Welcome to my excuse to play with spinning rust 2:39 How to troubleshoot without killing myself 5:32 Let the testing begin! 7:33 Things go horribly awry… 10:46 Fixing my own dumb mistakes 12:51 Okay, back to where we started 14:30 Wait, wait, wait, check the obvious stuff first 17:37 Hey, five out of six ain’t bad! 21:33 Baby bunny! 22:16 Helps if you plug it in…The Forgotten Usagi: Ep. 02Usagi Electric2024-06-26 | This is a new thing we’re trying out, I have no idea how it’s going to turn out, but I’ve been wanting to give it a shot for a while, so here goes! This is a podcast/video… thing I’m doing with my good buddy AJ from Forgotten Machines. It’s mostly just two dudes chatting old machines. Minimal editing and a bit longer than my usual fair, let me know what you all think!
Chapters 0:00 Introductions 1:05 The elephant in the room 3:20 What happened at AJ’s booth 11:58 What happened at Usagi’s booth 19:55 When to use emulation? 25:21 What about VCFSW 2025? 27:49 What is too new for a vintage festival? 33:05 Can an iPhone 1 be restored? 38:54 What’s coming up next on FM and UE? 41:14 The Usagi was not Forgotten! 41:57 The train left the station, and I wasn’t on it…FM is RLL, MFM is RLL, RLL is RLL! Fight me.Usagi Electric2024-06-23 | The EDS PC is a fascinating machine, but where we last left off, it didn’t have a functional hard drive. It has an ST-238R in it, which is an RLL drive with appropriate RLL controller card, but the drive did not seem all too happy last time we spun it up. In this episode, I want to try to rescue the data off the drive using David Gesswein’s amazing tool, but also, I want to learn a bit more about FM, MFM and RLL in general.
Chapters 0:00 How fast is too slow? 3:38 FM, MFM, RLL and the ever important… RLL? 10:48 Imaging an MFM drive (which is really RLL) 15:42 Imaging a not crap MFM drive (which is still actually RLL) 18:57 Imaging an RLL drive (which is… also RLL…) 23:00 Giving the RLL (not MFM) drive a shot 24:12 Giving the MFM (yes RLL) drive a shot 33:02 How fast is excellent? 36:24 Baby bunny! 37:15 Don’t anger the Youtube Gods…Only DEC could make a PDP-11 PSU this insane…Usagi Electric2024-06-16 | In a haze of jet lag, I woke up with a burning desire to get hands on with my PDP-11/44. It’s been sitting on a back burner for an intense amount of time, but even still, it hasn’t been a high priority item. But, sometimes, you can’t help wanting to work on certain things, so in this episode, I give in and have a bit of fun tooling around with the PDP-11/44!
Chapters 0:00 Who needs responsibilities, let’s work on something fun 1:00 The who, what, where, why and when 3:51 Taking things apart 5:09 Even at first glance I can tell this PSU is gonna whip my butt 6:50 Initial testing 9:06 Fan cleaning and testing one more time 10:44 Okay, it’s broken, but how broken? 14:55 Hands on with the PSU modules 16:38 Swapping different modules in and testing again 21:39 Losing the battle, but still hoping to win the war 23:10 Another rescue?!Assembly Programming is Hard…Usagi Electric2024-06-09 | VCFSW is marching ever closer and to make matters a little more interesting, I’m currently on the other side of the planet. (Though, to be totally honest, I’m actually writing this description on the plane.) That leaves me with just two days before I fly out to get the fixed platter of the mini-Centurion low level formatted. Sounds easy, right? Well, we gotta program a new, bare-metal assembly program to do that formatting for us, and that’s anything but!
Chapters 0:00 Schedules man 2:10 Cowabunga it is! 6:19 Will this collection of bad ideas work? (Nope) 8:25 Last chance 11:00 Success! 15:03 Life is tough when you’re dumb 19:09 Koma-san!The Forgotten Usagi: Ep. 1Usagi Electric2024-06-02 | This is a new thing we’re trying out, I have no idea how it’s going to turn out, but I’ve been wanting to give it a shot for a while, so here goes! This is a podcast/video… thing I’m doing with my good buddy AJ from Forgotten Machines. It’s mostly just two dudes chatting old machines. Minimal editing and a bit longer than my usual fair, let me know what you all think!
Chapters 0:00 Introductions 1:50 AJ with Forgotten Machines 7:57 A talk about weird data 9:58 A question about floppy images 17:08 Floppy emulation is hard, yo 24:04 What are we bringing to VCFSW? 29:45 A special exhibit at VCFSW 32:47 Dragged kicking and screaming into the world of emulation 43:11 Outroductions 44:32 Apparently, the Usagi was literally forgotten…Software Problems? Hardware Solutions!Usagi Electric2024-05-26 | VCF Southwest is barreling down on us real fast, and some of my junk works, haha. The CDC hawk drive is almost there, only it’s giving us even more grief now and the data terminal takes a dirt nap everytime we throw data at it. Let’s see if we can coax some of this stuff back into life enough for the event!
Chapters 0:00 A funny story! 1:41 Alright, what’s broken now? 6:39 Swapping heads like it’s Frankenstein’s monster 9:25 Taking it for a test drive 12:10 Shady business practices striking 40 years later 15:33 Finally getting to the data terminal 16:59 Comparing the Regent 100 and Regent 200 19:38 It couldn’t have been easy, could it have? 22:17 Shifting gears and digging into the MUX card 24:45 Building and testing the daughter board 29:01 Hacky hardware solutions! 31:26 Koma!Reviving a 1970’s Hard Drive for the Mini Centurion!Usagi Electric2024-05-19 | VCF Southwest is barreling down on us real fast, and none of my junk works, haha. Time to hunker down and start getting stuff over the finish line. The Mini-Centurion is specifically meant for shows and right now, it doesn’t have a hard drive. So, in this episode, we dive in deep to try to bring the old 14” Hawk drive that’s bolted to it back into the land of the living.
Chapters 0:00 Carry on my wayward son… 5:56 Power supply shenanigans 12:30 Head cleaning and disk inspection 15:08 Loading the heads and failing to boot 18:18 What went wrong? 20:37 Repairing the drive and aligning the heads 26:14 Test drive 28:08 The good, the bad and the ugly 31:20 ニャラリーThe Rarest IBM PC Clone in the World!Usagi Electric2024-05-12 | The Centurion is one of my all time favorite minicomputers, but did you know, they also made an IBM PC Clone? Well, they almost shouldn’t have. The story of this thing is absolutely bonkers, and the story of how it got here is just as bonkers. So, tag along as dig in deep with a history lesson, and then try to get this old PC back up and running!
Chapters 0:00 This is not Doug Demuro 0:31 Brief history of Centurion 2:50 Why does the EDS PC even exist? 4:44 How did it get here? 11:11 Cleaning up the monitor 12:42 Does the monitor even work? 15:18 Let’s dig into the PC itself 17:51 A closer look at the motherboard and cards 25:27 Putting it back together and turning the switch 26:49 Let the troubleshooting nightmare begin 31:35 Will it boot? 32:56 I hate foam and foil keyboard with a passion 36:41 All clean and back together, will it get to DOS? 39:29 Plugging the Centurion into the Centurion 42:25 Kitties!The Mini-Centurion is Back!Usagi Electric2024-05-05 | With VCF East all wrapped up, it’s time to start prepping for VCF Southwest, which is coming up very, very soon! The party piece I want to have on display is the mini-Centurion, which we had on display last year at both East and Southwest. But, all the travel has taken its toll. Couple that with us swapping the CPU6, 128k MEM and Hawk drive with the Desk System CPU5, 32k MEM and Hawk drive up at Butler Tech., and we have a serious mountain to climb before we’re ready to display. So, let’s get to work!
Chapters 0:00 Time for VCF Southwest! 1:33 Where did all this different hardware come from? 5:42 Woodworking 9:32 And now, the news! 10:38 Paintwork 12:21 Side panels 15:18 Getting them mounted 17:45 Yeah, that turned out alright! 20:27 We love you and miss you Chibita!Health Update and a Really Cool Disk Pack!Usagi Electric2024-04-28 | VCF East was an absolute blast, but it had one final parting gift to give me – an upper respiratory virus of some kind. Usually, I recover from these kinds of things in a day or two, but this one was particularly brutal and put me down hard for eight days! I’m finally starting to literally get my feet under me again, so unfortunately, there won’t be a traditional video this week. But, I didn’t want to leave y’all hanging completely, so hang around for a short little story from VCF that I particularly enjoyed!
Chapters 0:00 The video is so short, who needs chapters!VCF East 2024 + Museum Tour + PDP8 Fun!Usagi Electric2024-04-21 | VCF East 2024 + Museum Tour!
One event I’m always looking forward to is VCF East. Not just because it’s a stellar congregation of amazing people, but because there also happens to be one heck of a museum on campus as well. Let’s take a walk through the event, look at some of my favorite exhibits, and then hang out in the museum, and maybe even get hands on with one of their machines.
I had an absolute blast hanging out and learned a ton! Can’t wait until next year!
Chapters 0:00 What is VCF East 1:05 The show 5:08 Usagi’s best in show 7:06 The Museum 9:50 Some of my favorite pieces 16:30 A wild PDP-8 appears! 22:42 Running a proper program on the straight 8 25:59 Bunny!Co-Op Snake on a 1980’s Business Minicomputer!Usagi Electric2024-04-14 | The Centurion is an epic piece of hardware – able to support up to 32 simultaneous users and over half a gig of storage, it’s an absolute beast. But there’s once thing it can’t really do, and that’s game. Today though, we fix that! Bu, single player games don’t make a whole lot of sense on a system that can support so many simultaneous users, so something a multiplayer co-op game would be pretty epic to see, right? Well, that’s just what’s in store for today!
Chapters 0:00 What did $50,000 get you back in the day? 1:47 Multi-user and… 2:41 … big storage! 4:31 But, can it play Doom? (No, not even a little) 5:35 Printing out the code listing 7:57 Ran when parked, right? 11:21 The code listing (this is a long one) 17:43 Let’s assemble the thing 20:19 Setting up the terminals 24:18 Multiplayer co-op gameplay! 27:38 Do copy that floppy! 31:08 Printing a label and making it look good 31:42 Vim and an Emulator! 33:20 Sunny-kun!Doing Carburetor Work on the Austin Healey 3000Usagi Electric2024-04-07 | Sometimes, you just need a break. A lot of things that we work on in the room have very similar failure modes, which means it’s easy for your brain to get stuck in a loop. The best way to break from that is to change gears completely and do something wildly different, like working on some old SU carburetors on one of my all time favorite cars!
Chapters 0:00 I need a break 1:19 My first passion 3:57 A very special car 5:22 Carburetor work 10:42 Plug work and a wash 14:28 Let’s go for a drive! 19:12 Kono san!The Bendix G15 Typewriter is Crazy Pants!Usagi Electric2024-03-31 | As we barrel towards DC full speed ahead, there’s one last large hurdle we have to overcome – the typewriter. This thing is insane on multiple levels. Sure, it weighs about 70 lbs. and some crazy fool slapped a 28” platen on it, but also, it’s been heavily modified by Bendix to send the weirdest collection of data-bits and signals back and forth with the computer. Come on along as we dive down the weird and wonderful rabbit hole of the G15 Typewriter!
Chapters 0:00 Who let me get my hands on a piece of history? 1:25 The story so far 3:07 A normal typewriter you say? 4:15 5-bits is 5-bits is 5-bits 6:34 But wait, there’s more! 7:16 The Monty Hall problem, if it were switches instead of doors 8:53 Scrub-a-dub-dub 10:24 Madness lies that way 12:00 Alright, back to work you! 13:16 Can we make the platen move like it’s supposed to? 16:17 A little more scrubbing 17:33 “Hellorld!” 18:45 This thing is a marvel of mechanical engineering 21:19 VCF and the Open House 22:02 Sue and MeiThis NEC PC-8001 is Epic!Usagi Electric2024-03-24 | I’m mostly focused on large scale systems as of late, but that’s not to say that I don’t find microcomputers fascinating. And one such machine I’ve had that’s been on the back burner for literal years is this NEC PC-8001. It’s time to get this thing up and running, and maybe even take it for a proper test drive!
Chapters 0:00 I don’t have that many micros… 2:19 Where did this PC-8001 come from? 3:34 A quick look 4:54 Showa era is the best era 6:07 The motherboard 7:57 Japan’s bonkers power grid 10:19 Where that video hiding out at? 13:18 First proper power up 14:17 Let’s go for a test drive 20:22 Final thoughts and Project Euler 23:52 The cutest combo on the planet!Still Broken… but, Different Broken!Usagi Electric2024-03-17 | In order to have a portable PDP-11, we need a portable data terminal. In the previous episode, we took a bath in rodent feces trying to revive our little ADDS Envoy, which is perfect for this task. But, we didn’t manage to get it up and going. We’re taking another swing at it today, but as is obvious from the title, it didn’t go well. However, it did make some progress!
Chapters 0:00 Our goal of a portable PDP-11 2:22 Check the power rails first! 5:17 Did that fix it? (Hahaha, seriously?) 6:48 After a full day, where are we? 11:50 Trying to repair the bad FE/GT to compare to the good FE/GT 13:40 Okay, back to the original FE/GT… 16:03 That should have fixed (so why is there still 10 minutes left in the episode?) 16:44 The real smoking gun? 21:06 Still broken, but broken in a different way! Yay! 24:39 Cue battle musicState of the Usagi 2024!Usagi Electric2024-03-13 | My fellow hobbyists, welcome to the first official State of the Usagi address, where we’ll talk about all sorts of stuff, from where I’ll be in 2024 to what we’ll be working on, and even a little bit about the channel and merchandise.
Chapters 0:00 My fellow Usagis… 1:30 Where will I be in 2024? 5:38 What will be working on in 2024? 10:51 Merchandise and microphones 13:12 First lady KomaVTC P.36 – Logic Done!Usagi Electric2024-03-10 | Our DIY vacuum tube computer hits an insane milestone today – we finish up the logic! All that’s left after this is building out the paper tape and running code on it. We’re so close, so come along as we finish off the last little bits!
Chapters 0:00 The story so far… 4:06 A quick refresher 8:15 Hershey kisses of molten metal 10:46 Plugging in the easy stuff 11:40 Cathode follower buffers 15:25 Cathode follower buffers… again 17:42 Catho… I’m gonna stop you right there… 19:27 Blinkenlights! 21:50 Soft start 24:58 A massive milestone! 26:42 “My name is Sue! How do you do?! Now you gonna die!”Printing ASCII “Art” Like it’s 1980!Usagi Electric2024-03-03 | This is it – the Data-100 printer prints in this one! And, if we remember back all those episodes ago when I was looking at the CPU5 data platter, there was a file called “GIRL82.” Well, what better way to test the printer than by printing out some vintage ASCII p… err… science!
Chapters 0:00 What is a Data-100 printer? 2:36 Can’t touch this. Hammertime. 5:43 Plugging it in and setting it up 7:50 Test prints 9:39 Re-inking the ribbon 12:19 Cleaning up the rest of the printer 14:27 The infamous “GIRL82” 16:43 Curse you Red Baron! 20:00 Now that the printer is done, what’s next? 21:39 Baby bunnies!The G15’s Bonkers Optical Reader and Punch!Usagi Electric2024-02-25 | We’re slowly inching our way closer and closer towards bringing the DC up on the G15. We have just a few more challenges to tackle, namely the paper tape reader and punch. This system is pretty wild looking with all sorts of electrical shenanigans and electromechanical wizardry. In this episode, we take a much closer look at it and try to get it as clean as we can in preparation for the big day!
Chapters 0:00 Who let me get my hands on a piece of history? 3:27 Money, money, money 5:45 Disassembly 7:50 Preventative maintenance? 10:12 A look at the motor control section 12:01 A look at the optical reader 13:34 The elephant in the room (the punch) 18:44 First, a quick clean 20:15 Much ado about selenium 22:10 What’s next? 24:53 The babies!I Love this DEC LA50 Dot-Matrix Printer!Usagi Electric2024-02-18 | Honestly, I was planning on skipping a video this week. It’s been an emotional roller coaster of trips to the vet and struggling to keep animals alive. I’ve been an absolute wreck, and apparently, I was looking so haggard, Mrs. Usagi told me to go outside and do something to reset my brain. So, this week is a bit of a shorter video, but it got the job done and injected a little joy back into my week!
Chapters 0:00 It’s been… rough 2:41 Cleanup 3:47 First power up 5:36 Self testing 6:37 Trying to print from the Rainbow 7:57 Battling baud and data settings 9:25 Actually printing from the Rainbow 10:03 Some interesting quirks 13:47 Sue san!This Data Terminal was Covered in Poop!Usagi Electric2024-02-11 | We’re still plugging away at our portable PDP-11, and in the last episode we made excellent progress in getting the PDP-11/23 itself up and running. But, a portable PDP is pointless unless we have a portable data terminal to go with it. Enter the ADDS Envoy. This is an awesome little RS-232 capable data terminal that will make the perfect companion for our PDP-11. The only downside is, it’s in rough shape. Or at least, one of them is, it just takes me way too long to figure that out. What am I on about? Well, watch the video and see!
Chapters 0:00 This is our portable PDP-11 2:05 A portable PDP needs a portable data terminal 3:45 A virtual walkaround 6:52 Disassembly 9:53 Guess what, more poop! 11:53 Cleanup 14:54 Testing the power supply 16:51 “Everyone knows you never go full send!” 19:15 Properly checking voltages this time 21:14 “I’mma let you finish, but Tool had the best album of all time!” 22:29 The “parts” machine 24:06 Testing goes better this time 26:45 We’re close, but not quite there yet 29:14 Koma-san!The Largest Printer I Own Prints!Usagi Electric2024-02-04 | Ever since I got the Centurion a few years back, that number one requested item I work has been the massive Data-100 chain printer. Well, that time is now! In the previous episode, we double checked the power supply and saw that it was good, so we are clean and clear for working on the rest of this beast. The title spoils it a bit, but we actually throw the switch and get it printing out some test pages today, and y’all were right, this thing is epic!
Chapters 0:00 Revisiting the power supply and voltage levels 2:39 The plan 3:42 Taking it apart so we can actually clean the thing 5:18 Wait, what even is a chain printer? 8:24 Actually cleaning the thing 10:05 First test 12:19 Second test (actually the third, I put the ribbon on wrong twice) 13:16 Okay, what happened? 15:17 Hammers and plastics 18:17 Third test (actually way higher than that, but you know, narrative coherence and all that) 18:52 Did we snatch victory out of the jaws of defeat? 23:04 Sue!Reviving 65 Year Old BearingsUsagi Electric2024-01-28 | In the previous episode, we brought up AC on the machine for the first time in who knows how many decades, and it went amazing. We confirmed that we have a good clock track and a good timing track on the drum. But, we also confirmed that none of the cooling fans were happy and the drum itself was grumbly. So, today, let’s pull those fans out, revive the bearings in them, then pull the drum out and try to get the bearings in it happier as well.
Chapters 0:00 I love this blue monolith of a computer! 2:54 Removing the door fans 5:15 Reviving the door fans 9:24 Removing the main blower fan 12:10 Reviving the main blower fan 14:29 Removing the drum 16:41 Fixing the drum with a hammer 18:23 Flipping the big switch one more time 20:20 All it took was a little patience! 22:31 Kitty!The PDP-11/23 Plus Works!Usagi Electric2024-01-21 | Last episode, the PDP-11/23 11/03 Hybrid we were building absolutely crushed me. Well, to be fair, we never even got as far as testing the CPU, we got crushed by the power supply. I threw everything I had at it, and emerged the very opposite of victorious. I retreated to my corner, and armed myself with more knowledge, and now, stepping back into the ring for round 2, I absolutely will emerge victorious! How though? Well, you’ll just have to watch to find out (it was negative voltage).
Chapters 0:00 It’s cold y’all 2:29 Revisiting the regulator design 7:00 The negative voltage 8:56 Working on the -15V rail 11:34 A tale of two diodes 14:13 Come on man, you can do this 16:45 Nice, the PSU works. Now what? 19:46 Legen- wait for it -dary 21:38 Let’s get it to misbehave a bit 24:26 Time for a lot of y’all to click away 26:00 If you clicked away, you missed out on this 27:05 Sunny-kun!This PDP-11 Power Supply Defeated MeUsagi Electric2024-01-14 | My PDP-11 story is a weird one. I found myself with too many PDPs, so I had to thin the herd, which left me without a running PDP-11. The goal for today was to fix that by bringing up a PDP-11/23, but the power supply had other plans. After a full week of troubleshooting, I emerged from the room defeated. But just what went wrong? Well, let’s dive in and find out!
Chapters 0:00 My PDP/DEC Story 3:54 What problem am I trying to solve here? 5:07 The PDP-11/23 CPU and Memory cards 6:39 The PDP-11/03 AA Backplane and PSU 8:22 Let’s clean this thing up first 11:17 First test 14:05 Second test 14:42 Nothing is ever easy… 17:30 Third test 18:29 Why is this going so poorly for us? 24:07 Fourth test 26:05 “I’m calling it, time of death, probably 30 years ago.” 29:22 Puppycat!Working on the Largest Printer I OwnUsagi Electric2024-01-07 | Ever since I got the Centurion a few years back, that number one requested item I work has been the massive ODEC made chain printer. Well, the time has finally come! Let’s get this printer out into the open and dive right in.
Chapters 0:00 The story so far… 2:12 What’re we missing? 3:43 Initial disassembly 5:18 A close look at the electronics 7:17 Getting the power supply free from its cage 9:09 A brief look at the power supply 11:27 Reviving the capacitors 14:05 First electron test in probably 30 years! 15:56 That went swimmingly! 18:57 Bunny!My New NASA Minicomputer!Usagi Electric2023-12-31 | A couple of months back, a very kind gentleman by the name of Godfrey reached out and asked if I wanted to take a crack at restoring an old minicomputer he had. After seeing the pictures, I was 100% on-board, because not only is this Data 620 a brilliant, transistorized machine, it also happens to have come from NASA. Being built in 1965 or 1966, it was used at NASA right through the entirety of the Apollo program, so it’s entirely possible this big, blue, beautiful beast actually contributed to sending people to the moon!
Chapters 0:00 Welcome Mr. 620! 1:55 Stripping and repainting 4:47 Reassembly 8:04 Rearranging the room 9:14 Looking dapper 11:08 A dive through the brochure 17:40 Memory Power Supply 19:18 I/O Control 21:10 Core Memory 23:31 Front Panel 25:54 Central Processor 28:54 Hellorld NASA-kun! 32:51 Happy Fuzzy New Year!The G15 Lives!Usagi Electric2023-12-24 | This is the big one, this is the one where we throw some electrons at the Bendix G15 and see what happens. But, bringing up one of these machines is no simple task, and even if we throw electrons at it, that doesn’t mean it’ll be ready to execute code. All we’re doing today is confirming the condition of the drum by just bringing up the AC. The drum should spin up and the sequencers should sequence, and finally we should be able to see the clock track and timing track. If that all goes well, then the title of this video is totally not clickbait!
Chapters 0:00 Who let me get my hands on a G15? 1:53 What are we doing today Brain? 3:36 How do we even power this thing? 4:51 Okay, what happens when we flip the switch? 8:07 What good does that do us? 10:05 And how do we confirm that the clock and timing tracks are good? 12:40 Enough questions, do the thing! 15:20 That… wasn’t a great sound 16:17 Do the thing again! 18:30 Confirm those tracks! 21:20 Heck yeah! What’s next? 25:56 Merry Furball Christmas!Restoring an ADDS Regent 200 Data TerminalUsagi Electric2023-12-17 | Earlier this year, I ventured all the way up to New Jersey to attend VCF East. Aside from the fact that that was just a staggeringly cool event, it put some things in motion that have been awesome to say the least. Once of the things I’m quite excited about is this little data terminal here. I’m an ADDS fanboy, I think they build some amazingly cool looking data terminals, and I’m beyond stoked to get this ADDS Regent 200 back up and looking fresh again. So, let’s just dig into it!
For more information on VCF, check out there website here: vcfed.org
Chapters 0:00 A VCF hoodie 1:59 What are we looking at today? 4:28 A quick test before disassembly 5:39 Ripping it all apart 9:11 Cleaning and painting 13:57 Good googly moogly, that’s a pretty terminal 15:34 Testing it hooked up to a computer 18:14 Still a little left to do, but overall, a massive success! 20:25 Sunny-kun!VTC P.35 – Building the Output RegisterUsagi Electric2023-12-10 | Our DIY vacuum tube computer is making excellent progress. In this episode, we need to get the output register built, but it is subtly different to the scratch register, which is going to take a little bit of a change in the PCB design to knock out. So, let’s take a look at how the scratch register was built and then how we have to change that to make the output register work like we need it to!
Chapters 0:00 Introduction 0:45 Thank you so much Patrons! 2:58 A 1-bit computer with 2-bytes of memory 6:15 The scratch register 9:07 The output register 12:10 Let’s build that PCB! 14:02 Testing 15:05 That’s not good… 16:36 Let’s try this again! 20:06 Excellent! What’s next? 22:38 She climbed into that spot herself…A Vacuum Tube Single Board Computer?!Usagi Electric2023-12-03 | The UE-1 is one of my favorite projects to date, but there’s no denying that it’s weird as far as computers go. So weird in fact, nearly everyone who got hands on with it at the last event I had it at was completely lost as to what it was or how it worked. That got me thinking that a little handheld vacuum tube computer built using the same core concepts as the UE-1 would be great for introducing people to the concept of 1-bit computing. In this episode, I build up exactly that, with a little help from my friends at PCBWay!
Chapters 0:00 Hello and welcome back 1:21 Why is the UE-1 so weird? 3:56 A crash course in the UE-1 5:28 What if we simply it as much as possible? 8:48 Logic diagram into PCB 10:38 First power on 13:16 That didn’t go well 14:20 Let’s take this thing for a test drive 17:02 How hard can it be to add 1+1? 20:04 Well, there we have it 21:51 Bunny!Will This Rare 1980s HDD Live Long Enough to Save the Data?Usagi Electric2023-11-26 | A little while back, we ventured out to Tennessee to visit a cool little Museum called Vintage Geek. It was an epic trip, but the main reason for the journey was to see the very cool Centurion MicroPlus that Aaron had. We couldn’t get it up and going in that episode, so the Finch drive, which should have all sorts of cool stuff on it, came back with me to hopefully rescue the data on it using my big boy Centurion. The drive is wounded and unhappy, but will it play ball long enough to save the data? Let’s find out together!
For more information on Vintage Geek, check out the website here: vintagegeek.com
Chapters 0:00 Where we are and where we’re going 2:00 The Vintage Geek Finch 4:28 Finding the short 6:50 Wiring in power 8:09 Making room for the new data 11.36 Preparing the OS 13:14 She’s very much so not healthy 16:04 Let’s try to load the heads 18:33 Swapping PCBs 21:10 Welcome to troubleshooting purgatory 23:38 Victory? 26:43 Hah, there’s no victories here! 27:44 Down but not out 31:01 Victory! (For real this time!) 33:23 Let’s take a second, and wrap our heads around what just went down 36:45 Sue!The Ultimate DEC Rainbow and a PDP Question for You!Usagi Electric2023-11-19 | Our DEC Rainbow is a pretty neat little machine, being a fully triple boot system – can boot DOS, CPM or into VT100 terminal emulation mode. However, it was still missing some vital components to really turn it into the best of the best. First and foremost, the VR241 color monitor. We managed to get a Princeton Ultrasync to work, but it’s not what’s supposed to be bolted to it. Next, we were a little low on RAM. And finally, we were missing the best expansion of them all, the RD51 Winchester hard drive option. Today, we fix all three of those!
Chapters 0:00 Hello and welcome back… 2:09 John the legend! 3:46 Disassembly 5:57 A close look at the hardware 8:21 Cleaning time 9:34 Time to make a new cable 11:42 Round 1, fight! 12:55 Round 2, maybe don’t fight as hard as round 1… 15:36 Clean that floppy drive 16:40 Round 3 21:24 I got a question for y’all about PDP-11s! 24:43 Sunny-kun!Restoring an HP-120B Oscilloscope from 1961!Usagi Electric2023-11-12 | I have a soft spot for old test equipment, particularly old HP test equipment. My HP-150A is my all-time favorite oscilloscope. It’s rock solid, looks gorgeous, and is stunningly good. It also weighs about nine million pounds (that’s roughly four million kilograms). I was lamenting that I needed a front-end loader to pick my 150A up to a good buddy of mine, Chris Fala, and he said “I’ve got an HP tube scope that won’t send you to the doctor for back pain.” Chris is an absolute legend and hooked me up with said scope, which is the HP-120B you see here today. It’s not currently working though, so let’s dive into it. Should be easy, right? Right?
Chapters 0:00 A bit of reorganization 2:34 Scopes! 4:43 Testing the test equipment 5:40 Throwing electrons at the 120B 7:25 Deep cleaning time 12:43 6U8 vs. 6GH8 14:05 Testing after cleaning 15:21 So close, let’s dig in deeper and find out what’s wrong 17:38 Thor: “Is it though?” 19:35 I fought the HP and the HP won… 21:56 Battling someone else’s modifications 24:11 Please work correctly, for my sanity’s sake 25:48 Nailed it! 26:48 What am I going to do with another oscilloscope? 28:46 Derpy cat is derpy