My New Computer Weighs 1,000 Pounds!

[Music] thank you hello and welcome back and today we have something pretty special to show you guys but it almost didn't make it here today it was supposed to be delivered this morning but I got a call from FedEx freight saying that it wasn't actually going to make it here today it was going to make it here tomorrow but we had stuff planned and so well we just weren't going to get our uh our delivery but I called an audible and I said you know what FedEx freight do you mind if I actually came and picked it up myself and they agreed so we loaded up the trailer we went out to FedEx freight and we loaded up these two boxes this is what was being delivered uh now there's something amazing hiding out in here and I'm gonna show you guys what it is but I don't want to spoil it just yet however I think you can maybe infer what's going on here because this box says 1256 pounds on the side this one says 258 the one that I'm sitting on so we have a combined 1500 pounds which is some ridiculous number in kilograms like 600 kilos or something of interesting Computing something so let's pop all of these little clamps off of the big box here pop all the clamps off the little box here take a look inside and see what Treasures await us let's rewind for a brief second to getting these massive boxes off of the trailer and we tied them down with no less than seven tie downs for the trip from FedEx to here then I just manhandled the 250 pound box to get it lined up and out came our Kubota la-844 tractor with front end loader and we actually got a forklift attachment for the loader that made this an absolute Breeze though you do have to be mindful and move slowly and deliberately and with the little box unloaded it was time to go back for the big boy and at 12 hundred pounds we were a little worried but the Kubota never even broke a sweat we just picked it up and drove it straight into the garage and we had no problems at all so what's inside these boxes well let's start with the little box there are these cool little tabs that hold the top on and you just Hammer a screwdriver underneath them and bend them up and once all the tabs are bent up the top pulls straight up and off and I I think they were having a sale on Bubble Wrap because it is insanely well packaged in here so let's speed this up a little bit and I'm seeing some pretty distinctive teal colored panels in there and a typewriter as well as some mystery boxes this is getting pretty exciting so next let's open up the big box it has these little pockets and specially shaped clamps that hold it all together you just put the special tool in the Gap give it a little bit of a Twist and the clamps just pop right off and CJ and the guys at system Source did an astonishing job packaging up this Behemoth and it was very well covered in bubble wrap and packing blankets and man it's a ton of fun to unwrap this thing it's kind of like Christmas and looking at it definitely like Christmas that's pretty special know your eyes did not deceive you what you just saw get unpacked is this machine right here and this is a Bendix g15 a full on vacuum tube computer from 1956. ah it's so cool every time I look at it I lose my train of thought this thing is awesome this is actually owned by Bob at systemsource Museum in Maryland and if you haven't heard of system Source go check out that museum it is in unbelievably good Museum they have astonishing machines on display from a Xerox Alto to a univac that's the size of an apartment all the way down to an apple one it is an absolute bucket list visit if you are into Retro Computing or vintage Computing in any manner but Bob also has a g15 on display there but that wasn't the only g15 he had there was one more in the back that he was hoping to get up and going and since I've been dabbling a bit in vacuum tube Computing trying to build my own one-bit vacuum tube computer from scratch Bob got in touch with me and we started to maybe work out a deal to get one of those g15s here to Texas and well as you can see that actually happened but getting it from the palette it was on into this room so I could talk about it was a journey in and of itself because the original casters were quite small and starting to come come apart and they had a really interesting bolt pattern on it that was square and very compact I don't understand how this thing ever rolled on those Casters in the first place so I needed to replace those and get some big boy casters on it so it could roll on the industrial carpet that I have on top of concrete in this room in here but how do you make new casters for a machine that weighs a thousand pounds that's right the thumbnail for this video is not click bait this machine weighs in just a hair under a thousand pounds about 960 to 980 or something like that it is without a doubt the heaviest most densest piece of Machinery I've ever come across so getting new casters to fit is going to be an interesting battle I was talking with Ian and Thomas over at VCF about this and Ian had this idea here which I figured I could adapt to what I needed the first step was drilling mounting holes in the bolt pattern of the original Caster then I sliced up some nice thick Square Tubing to the correct length on our bandsaw and welded the newly cut Square Tubing to the top mounting plate now the welds are plenty strong but not very pretty so you know a grinder and paint makes me the welder I ain't then I welded this to whole concoction directly to a 250 pound Caster four of these casters should give a combined capacity of a thousand pounds which should be plenty for this machine and now it's time for that paint to cover up my ugly but strong welds and it should be noted that I went back later and added in some supports to make it even stronger so these ultimately got two coats of paint on them to get the casters on I have to take all of the lower panels off the two front panels are held on with five screws from the side and three screws from the back two of which go through this latch that holds on the side panels which I did get they're just stored over in the corner to keep them safe for now and with all the screws removed the panel pulls right off and next let's get the back panels off the center panel is held on with six screws though the lower two were missing and the panel is actually bent so we'll have to fix that later but with the four remaining screws removed it pulls out and gives access to the main breaker we'll undo the two screws connecting the mains AC wires to the machine as well as remove the ground wire that goes to a lug on the bottom then I can finally fully remove the panel and power cord and then the remaining two panels come off the same as the front now in order to get to some of the bolts for one of the casters I need to get the capacitor Bank out of the way this massive collection of Sprague caps are paralleled for our primary filter caps I believe it's going to be interesting putting power in into these now we got a lift the machine up to get the casters off of the ground so I can remove them and put the new ones in and the manual literally says to lift it with a forklift because it has a dedicated frame underneath it specifically for this and sure enough that's the easiest way to get it in the air then comes the tedious process of removing the old casters and putting the new Casters in the clearance is really tight under there and it's really hard to get wrenches in place but here you can see a comparison of the new Big Boy casters next to an original Caster the new casters now have a little piece of metal welded in place and you can see the original adapter plate sitting on the top and once on and back on the ground it is Rock Solid and works beautifully well now that I can spin it around with ease let's do some basic cleanup I wanted to wipe off all of the really heavy dirt on the bottom half and then I moved up to the top half to remove the deteriorating seals around the door the stuff had turned to goo and was gross and needed to go then came the fun of trying to find a place to put this beast in the new office here I wanted it in the back corner which meant the pdp-11 had to move and I need to make better use of the space around the ue-14500 tube computer so I'm scooting it over and I thought about putting the PDP in the new space here but that didn't seem to work and so I tried the weighing wider and well that didn't seem to fit all that well either so let's put the PDP where the Wang Rider used to be and then I also wanted to get the xylog system 8000 that Uncle Stewie so kindly donated to the channel into the room as well and initially I was thinking I would put it here but I don't know this doesn't quite look right to me so instead let's rearrange this area and get the Wang Rider back over here just scoot it over a little bit but I'm gonna need some help from Mrs usagi to screw in a keyboard tray for the Wang Rider and and she does a little victory dance for helping out there then we'll get everything back in place reorganizing everything to make sure that it looks nice and finally I think the zylog system 8000 is going to work really well next to the ue-14500 I just need to scoot the two boards over to tighten up the spacing a little bit and uh yeah that all came together really really well I managed to stuff two new systems into the same space without having to remove any old systems Victory indeed now that we've rearranged the entire room to get the g15 in here and it is in here on some nice new Big Boy casters what is our goal with this machine well as you guys know I'm not a big fan of static displays I like to make things function and everything in this room works or well okay very little in this room works but the goal is to get everything in this room functioning I am not afraid to get elbow deep into a system to try and bring it online and that is what we're going to do with this machine in this series we are gonna try and get this machine up and going and executing code and fully functional we have all of the pieces we need to do it we just gotta hunker down and do the work and it's gonna be a pretty interesting battle to get it up and going we have some fascinating hurdle that we're going to have to overcome but if we do overcome them and we get this machine fully operating there is a chance that this might become the only fully working Bendix g15 in the country it might also be one of the oldest if not the oldest operating machine in the country that would be very epic indeed uh now it's really hard to throw around superlatives there's probably some machine out there that is older than this that is functioning or there could be another g15 out there that is also currently functioning I just haven't learned about them yet but either way this machine is special enough to be so close to being able to say superlatives that you can almost get away with saying them now once it is up and going where is it going to go after that well it's going straight back up to Maryland to system source so Bob can put it on display at that Museum and people can come see a real working functioning Bendix g15 in the flesh but well I'm getting ahead of myself we got to get this machine going first and like I said that there's going to be some fascinating hurdles to overcome so let's bring your camera in nice and close and I can show you guys some of the really exciting and interesting things about this machine and hopefully get you a little more familiar with it so that way when we dive into it in the coming episodes you kind of know where we're going and what we're working on starting on the side here these doors open up revealing all of the logic modules that make up the computer all of the tube modules are on the sides here with all of the diode modules here in the center and these are just cards that plug into a keyed slot on the back plane so this is a diode card you can see it's just got about eight diodes on it and a couple of resistors and that's really simple the tube cards are a little more complex but again the back plane is all keyed and they plug in just nice and easy this one has two dual triodes on it with a collection of resistors on here some of these resistors are quite precise one percent resistors but the rest are just uh 10 carbon composite resistors and this one actually has a couple of diodes on it as well this particular module is a gold colored module you'll notice that all of the module handles have different colors we've got gold green blue red black silver and there is one special blue that fits in a very specific spot on the other side in total including all of the tube and diode modules there's only about eight different variants for example all of the green modules here are identical and they're all interchange able you can pull them out and plug them into any spot and as I mentioned the back plane is keyed so you can't accidentally plug the wrong type of module into the wrong place and speaking of that back plane if you push the second button up here the whole door swings open revealing even more insanity and this is actually what makes up the real logic of the computer like I said there's only about eight different logic modules including the diode cards and the tube cards themselves and how they connect together is how you get complex interactions and this is how they're all connected together each slot has a coordinate and a pin letter so this row is the a row this first slot on the top right here is number 27 and for example maybe we want to look at pin p so a27p is going to connect to some other coordinate somewhere else in the system so if you're troubleshooting it that's how you're going to check it and speaking of troubleshooting we're going to need to do some of that because you can see there has been some wiring rework going on here there's lots of little blue wires here there's some kind of reddish pink wires here that are wired up to various spots on the back plane we have no idea why or how this was done or who did it at what point in its history so we don't know if any of that is correct or incorrect it's gonna take a lot of work to figure that out before we even bring up the high voltage in this and start testing it now just below the door is the party piece the heart of the machine this big nondescript looking box right here that says help me I'm inside the drum hand written on it by somebody probably 50 years ago this is the rotating drum memory you can see the massive AC motor that drives it right on the back there and that motor spins the quite happy drum on the inside that has a oxide material painted onto it that stores Bits And when I say this is the heart of the machine I absolutely mean it because so many important aspects of the machine are generated right here on the drum for example the clock that clocks absolutely everything in here is a read-only track on the machine and that clock is running at about 108 kilohertz it's about a nine point something microsecond pulse now the drum Works in a kind of unconventional way they use it as if though it were delay line memory of different lengths so you have long words medium words and short words and for example the short words repeat multiple times across the entire circumference of the drum this means that you can store a variable in a short word and get to it quickly without having to wait for the drum to make one entire Revolution now when I say they're using it like a delay line memory what I mean is that as a word approaches the read write head assembly it reads the first bit stores it into a flip-flop then erases that bit from the track and then based upon whatever operation we're doing whether we're just refreshing the memory or whether we're changing it and writing it a new value it will either rewrite to that same bit or change it and write the new bit back onto the drum so each Revolution every bit gets erased and Rewritten it's a really clever way of doing it but what It ultimately means is that well the memory doesn't count up like you would expect if you count it up just counting the pure raw bits that you can store onto it it comes out to about seven and a half to eight K of memory which is not a lot but you can do some pretty tricky stuff with it moving over to the front panel here we have a couple of interesting things we've got three really big meters here this one is a percentage of AC volts this one is a percentage of DC volts and this one is an hour meter now the hour meter says 3153 so it's had 3 000 hours on it and we're gonna hopefully get that hour meter counting up a little more now the percentage AC volts is pretty interesting when you flip this big start switch here that is so awesome sounding uh when you flip that big start switch the AC comes on first but the DC is still locked out and then you use this big knob over here to adjust a variac on the inside to make sure that your AC percentage here is right at a hundred percent this is just a fine tune your AC and make sure that it's spot on so that when you bring the DC up by pressing the reset button down here you can then adjust it to be pinpoint perfect and when that happens you're going to have the DC come up in stages and you're going to use this little knob here to go through and adjust the DC voltage individually to a hundred percent here because each one of these goes into a small little riostat on the back well small it's still pretty hefty but that allows you to get all of your voltages set correctly and then up here we've got some neon lights that give us a little more information we've got Source destination input output uh d a i don't really know what that is Overflow go halt test then we have command line characteristic and ncar I don't really know what most of those mean I've got a lot of learning to do on that but it's going to be awesome seeing those come up and illuminate just above the front panel is the paper tape reader and paper tape punch this is your primary way of loading in programs as a matter of fact one of the first program that you have to load via the paper tape reader here is the number track that gets written onto the drum so that knows essentially where a zero point on the drum is and the paper tape reader on this is fascinating because it's Optical it uses photo diodes which must have been absolutely out of this world for 1956 but also you can write new programs on this machine and then punch them out with this paper tape punch back here and store them that way so it's all built into the machine you don't need a separate reader and punch to sit next to it although Bendix did actually sell those but I think it's just absolutely awesome that this is all included and built into the machine and it's gonna put my Electro mechanical skills to the absolute test to bring this up but well it's a necessity to get the machine going so once we're confident and the rest of the the electrical systems and we've got AC going into it we're going to start to focus on heavily on this because it is essential for the machine that was just a lightning quick look at the Heavy Hitters of the g15 here but there is so much more hiding out in the details especially on that drum memory how it writes to that drum how it reads back from the drum the arrangement of the registers on there that's all fascinating and I can't wait to dig into that in more detail but it's gonna be a battle bringing it up because the well the first step we want to try to do is to bring the AC up which sounds like it would be really easy you plug it into the wall you flip the switch the AC comes up and then you can confirm things like make sure that all of the cooling fans are working that the blower motor is working and that the rotating drum is spinning up correctly but even that in and of itself is going to be very difficult because this thing requires 120 volts 50 amp AC input not 15 50 5 0. that is a huge amount of power so the reason that I wanted to put it in that back corner is that that is the physically closest location to the breaker box where we have 220 100 amp coming in so we've got plenty of power we just got to get it to this machine so we've got to punch a hole in the wall and put in a dedicated Bendix g15 socket just so we can bring this machine online and as we bring it up there's so much more stuff that I'm excited to learn about as a matter of fact I've been in touch with a local g15 expert and yes I realize how weird that sentence sounds a local here in Dallas expert of the Bendix g15 but this gentleman actually remembers programming these when he was young at school back in the 70s so he has first-hand experience with using one of these and he has a g15 himself that he is also working towards bringing up so we're going to work very closely together moving forward from here and hopefully we can bring two of them up together so earlier when I said this might be the only one well that may end up being false because we may end up having two fully functioning g15s by the end of this series but it's going to be a long Series so I want to thank Bob at systemsource so much for entrusting this beautiful piece of History to me Bob I won't let you down we're going to bring this thing up and we're going to Chronicle every step of the process so I hope you're excited Bob I hope you guys watching are excited because I am I'm going nuts I am so ready to get this thing going so I want to thank you guys so much for watching and I hope to see you in the next episode

Channel: Usagi Electric

Views: 14,434

Keywords:

Id: -RGp-bsYf34

Length: 25min 1sec (1501 seconds)

Published: Sun Jun 18 2023