Watched the other guy'd episode, earlier today. I love seeing this collaboration. I love this kind of "industrial archaeology". It is so reminiscent o the early days of rescuing the inland waterways of England (a.k.a. canals) and/or defunct steam engines being broken by scrap merchants. Future generations will be so pleased that you guy have done this, today. I wish I could ind such things here in the UK. Nothing survives!
If you can find like-minded people there's always a chance. The Data Museum in Denmark is run on a volunteer basis by an association set up to do so. Might serve as a model for the UK as well - if the railway people can do it, so can the IT crowd.
I just bought an industrial pc (sbc with backplane) from uk for 45 pound. I don t know the cpu yet, nor if it works. probably just a pentium, but hoping for 386 😂
Thank you so much! I find this stuff really fascinating and I'll do what I can to keep these old pieces of history up and going. There is quite a bit hiding out in the UK, it's just a whole lot harder to find it seems. I have a buddy there who has a decent collection of large scale machines that he's hoping to bring back as well!
I discovered this Centurion because youtube came up with a video of Vintage Geek. I recognized a centurion terminal send a reply with a link to Usagi Electric. Nice to see you found each other. 😀
Thank you! Centurion very nearly got lost to the sands of time, but I'm glad the community has come together to bring this little bit of minicomputing history back!
@@UsagiElectric No problem! I am trying to get my own vintage computers, but no luck so far. Have not checked desert industries, or goodwill. Really hope you can find more Centurions or more Centurion OS.
That smell of dust warmed by old components and then pushed out by fans well beyond their expected service life! I resurrected a few DEC machines back in the early 2000s, and it was such a joy when they came to life.
You seem to have become the only support for a centurion system. Keep it up, fantastic to see. Got to keep the vintage computing running, there is so much to learn from it.
Thanks! And becoming the go-to support guy for Centurion is something I will happily be! I'll keep working to get as many of these old systems up and going for others to experience.
I would put 5V across that board from a 1A or more power supply, and use a thermal imaging camera to see what gets warm. They are getting much more sensibly priced these days, TopDon do some great ones at sensible money. Another route I've done in the past is used a really good multimeter to search for the lowest ohms point, that helped me isolate a short circuit zener diode on a large (mostly logic) board from a high end massage chair.
Fortunately, I was able to bring the Finch home, so it'll be a good opportunity to test my short finding skills. I don't have a thermal imaging camera (though I should probably get one), but I do have a couple other tools that may be able to help. If all goes well, we'll bring both the Vintage Geek Finch and my Finch up together and back up all the data on them! Also, I never thought about it, but I suppose massage chairs would have logic boards, that's a fascinating corner of the electronics world!
@@UsagiElectric Constant current power supply limited to 1 volt or so several amps constant current. a bottle of isopropyl alcohol. power up the shorting rail . throw some isopropyl on circuit board. whatever parts of board the alcohol evaporates the fastest is where the short is
Yeah, you can even buy a device now that turns a cell phones into a thermal camera for iPhone and Android. I saw it on another channel of a guy testing one of these thermal cameras on his Iphone it lookslike it a mini thermal camera that uses your phone screen and power.
I don't know if this has been mentioned before, but on old hard disk drives (14", 8", and early 5 1/4") there is either no emergency head retract to a landing zone, or there is a NiCd or on larger drives, a Lead-Acid battery pack that typically provides the kick to bring the heads back to the landing zone before the loses much velocity when power is removed, thus keeping the heads flying during the move to the landing zone. Old magnetic drums (such as in the Bendix G15) have all the heads mechanically fixed in position, but due to temperature variations over time, they can lose their adjustment and potentially come into contact with the drum surface. The point I'm trying to make is that I've observed you turning the spindles on old drives (like the Finch in the Micro Centurion) and the drum memory in the G-15. This act by itself can make a storage device that was previously potentially workable, no longer so, by the heads contacting the disk physically dragging across the magnetic medium, damaging it. It's not a guarantee, but it is an avoidable potential problem by making sure that there is no contact between heads and magnetic surface before moving the rotating media. Just a suggestion for the future. All that said, I really love your channel. The joy you experience when resurrecting one of these vintage machines is positively contagious. Your on-screen presence is engaging and fun to watch. Your bunnies are positively adorable! I can't wait until you dig into the G15. It is a really amazing artifact, and will certainly bring back memories of my time working on a dual-CPU, transistorized drum memory computer made by 3M (Minnesota Mining and Manufacturing) in the mid-1960's that was used for process control. The machine had an 8Kx24 word drum in each CPU, had a bit-serial architecture, and the drums turned at 3600 RPM. The two CPUs shared a single 24-bit register with hardware interlock circuitry to prevent race/deadlock conditions when the CPU's were sending messages back and forth to each other. I/O was to a 33ASR Teletype, and a large-carriage IBM Output Typewriter. Input was from a huge bank of counters, digital to analog converters, and comparators that could be used programmatically to also function as analog to digital converters, as well as a real-time clock (Parabam transistorized clock using projection displays), input from the Teletype and Teletype paper tape punch, and a series a thumbwheel switches that could be read under program control. While I had access to the machine, one of the 8K drums suffered a bearing failure, and crashed the spinning media into the heads at speed, causing its total failure. The timing for the CPUs came from dedicated tracks on the drum, so the second CPU we no more. But, it was still great fun writing programs for the original master CPU, which ran for the entire five summers I had access to it (at the local High School, which the machine had been donated to by a local utility company). Programming was interesting, because each instruction contained both the operand address and the next instruction address, and in order to get maximum performance, you had to calculate both addresses by taking into account the rotation of the drum to allow quickest access to the information without having to wait for the drum to undergo another revolution. I'm sure you'll run into something like this with the G15 when you get it running....and I know you will! Best of luck in all of your computer restorations, and keep up the fantastic work with the videos. Sincerely, Rick Bensene, Curator, The Old Calculator Museum oldcalculatormuseum.com
Try getting through security in Myanmar with a suitcase packed full of fuses the size and shape of dynamite sticks and other various electric components and wires. And no one speaks English 😨 "Mingalaba" didn't work, I can tell you that much. I love these videos where two (or more) of my favourite youtubers get together and do a video! Thumbs up for that, and for you always being so helpful to people all around the US 👍
I started watching this channel because of my grand dad as he really relates to these old vintage computers. And to be honest, I have really enjoyed watching this series with him. With his help, I can follow along and understand what is going on and I find these videos about the Centurion fascinating. I hope that you have not forgotten about the printer restore. That might prove to be quite challenging I know, but you have managed to have a lot of really smart people help you with getting things working, and we here know you will eventually get that printer working too. Oh and the Phoenix hard drive! Don't forget that one! Today, the new tech just doesn't leave much to the imagination, but somehow the old stuff seems to open up an endless variety of possibility. Hard to explain. I have learned a lot watching, listening and reading comments. I am grateful.
At least with the drive dead (as a short) there's a chance there is still the os on it. Shorts are relatively easy to fix, lost os or programs could be a bit more difficult to replace.
if I had put up and kept all the stuff I tore apart when I was growing up id have my own little museum. if only I could go back in time and tell myself to just keep everything. I'm sure my younger self would just give me the finger and go right back to it lol.
I thought that was only me. I destroyed so many electronics taking things apart, I kick myself to this day. One of the best was a handheld Defender game with a colour VFD that ran on 4 C cells. That was such a fun game. That was almost 40 years ago and I have never seen another one.
Thank you for sharing. I use a Keysight bench meter with good quality four-wire Kelvin probes to find problems like shorted bypass capacitors - which I’ve had to do more than once. A regular Fluke meter may not be sensitive enough to spot a short. It beats having to unsolder or clip out capacitors. Another strategy is to apply current-limited power and then use an infrared thermometer to spot the unexpectedly hot capacitor. Owon makes some acceptable and affordable bench supplies which allow both output voltage and maximum current to be set. There are both switcher and linear models to choose from.
I love this channel. While they ran into a lot of trouble on this particular outing, I find these videos so soothing to watch. In a world that seems to gone mad, it’s great to relive some of the good old days
Sounds like a power spike took out the power rails, and just fused the first thing it could. That was the 5V in the Finch, the 24v line in the PSU, and obviously something funky in the terminal. Could well have been backfed power through the ground, maybe a faulty appliance pushing current through the metal cases?
Me too! I really want to build a replica (or even better, find another one). It's a really smartly designed case that has a great form factor for using on a desk.
I've manged to narrow down the location of shorts on power rails using an accurate multimeter in resistance mode (eg EEVBlog BM235 or your Fluke meter). Probe in multiple places to get all the readings that aren't zero, eg 0.3ohm, 0.2ohm, 0.1ohm. You end up with a map of where the short isn't, in the center of those 0.1ohm readings is the fault. lets say there are 5 chips in a row, and the outer two are 0.1ohm, well the chip in the middle (3rd IC) is the shorted one. ps: The axial caps with the metal can and transparent cover that are almost certainly branded Sprague, are Tantalum Caps, possibly just one of those shorted.
Guide to locating shorts on boards in general: Solution A: Get a really good multimeter with lots of precision, and measure your way towards the short as the resistance goes lower. This works adequately and is very non destructive, but sometimes the short isn't technically a short, but rather behaving a bit like a diode and needing some voltage to get going (typical of some ICs), then things get harder, since most meters considers it fairly high resistance, so one can walk straight past it... Solution B: Apply a suitably low voltage and look around for hot components. This too can be tricked by faults that needs some minimum voltage to appear, but one can slowly crank up the voltage towards what the rail is supposed to have. Just have a current limit on the PSU, and remember that SCR latch up is a thing, so sometimes this can kill ICs, especially in older equipment, so I would go for full rail voltage to start with, if you are lucky the short simply goes pop and you now know where it were. Solution C: One can also just poke around the board and compare it to a known good board. But then one needs a known good board, something you seem to have so this is a decent path. However, for power rail shorts this often becomes, "the power rail is shorted, else the two are measuring identically." so this method isn't really that good for this kind of fault.
That is really interesting. We never had any credit unions as customers in the Cincinnati area in the 1985-1986 timeframe. I wasn't as familiar with Cruze's Knoxville customer base, but I don't remember any mention either. So I've never seen one of these.
EDS's own sales teams sold most of the MicroPlus systems not the Centurion dealer network. EDS was selling the MicroPlus mainly to CUNDATA Credit Unions.
always like the old stuff.. like imagine a 2.5G RAM memory system with 500 core CPUs and a bunch of big platters and tape drives in some USAF cave from the late '60's...
If you're interested in a cheap solution for a thermal camera for tracking down hot chips, you can get thermal camera attachments for your phone for reasonably cheap. They're not exactly great compared to a dedicated thermal camera of high quality, but they're still more than good enough for tracking down bad chips.
@@UsagiElectric I first used an IR camera at work. Latter I bought a FLR camera that plugged into my android phone. That worked well. It combined the visual and IR image so it was easier to understand what you saw. But there was a problem. When I bought a new phone it wasn't compatible because it wasn't type C. So I bought a stand alone IR camera from Topdon TC004. It works well but doesn't have the visual image. It also has a threaded hole for a tripod mount. Good luck.
Yup! When I worked for an avionics company, we had a really nice Fluke brand IR camera. And it was almost just for pointing at a PCB to see what got hot. Great use for a $20K camera!
I always get confused when someone says a MUX. My brain goes into confusion mode. All it means is a multiplexer. Why does my brain do this. Love your work guys.
I watched Aaron's video yesterday. I guess it was a lot to expect everything to just work! You have some work ahead but I am confident it will all work out. I had a chuckle when you stated that you have three out of five known Centurion machines. There could be some other examples sitting in dusty warehouses or abandoned buildings, which is a bit sad. Most likely they will end up in a scrap heap.
Another method for finding where a short lives that does not require an IR camera is to hook the board up to a current limited power supply. Set the limit at around 1 or 2 amps. then start measuring voltages across Vcc - GND. Away from the short this will be a few millivolt. Closer to the short it will decrease to zero millivolts. This does require a very sensitive voltmeter though (and verifying that nothing is heating up).
We'll definitely get there! We knew from the start that the Finch would give us grief, I have a terrible track record with CDC drives, haha. I was surprised the floppy tripped us up though. Fortunately, it's a fairly common 8" DSDD unit and even if we can't bring that one up, we can always slip a replacement in there.
Very, very interesting computer, and something to learn! How to pack huge low integration ic boards into a pc sided desktop. I thought it's impossible.
Shorts tend to happen in power circuits. Either the regulator, or the output stage of whatever drives the heads or spindle motor. It's less likely to happen on some random TTL chip.
@@ingmarm8858 Which we did. Just because it didn't make it into the video doesn't mean it didn't happen. We powered up the supply completely empty and nothing bad happened but the rails were good, so it was kind of boring to show. Then we plugged in the floppy the main PCBs. The floppy having a dead short on the +24V rail is most likely what caused the pop.
Its usually possible to find a shorted tantalum cap with an ohm meter. You should see the lowest resistance across the shorted cap and a nominally higher (but also low) resistance across the good ones.
A marvel of space utilization. Too bad that both drives had issues but not that surprising. No one that designed or built them intended them to survive 50 years.
Awesome news that another Centurion has been found! Fingers crossed for getting that drive running. I've one question though, what's the rabbits name? ;) Great video - highlight of my evening to see it appear in the feed.
Thanks! I usually show about three different rabbits in the end, but the one shown in this video is "Kome," which is Japanese for "rice." Unfortunately, she passed a couple years back, but she was our little adorable rice ball, haha. The other bunnies I show are our current bun "Koma," which is Japanese for "troublemaker" and "Kono," the light brown bun I show on the occasion, who was our very first bun when we were living in Japan.
My father designed and built the thick film hybrid memory modules for General Automation minicomputers. Is this something of interest to you? Maybe you know someone who might find this interesting?
Heya! Working on a Bendix episode right now, it'll be going up next Sunday! The Litton is on pause while I hunt down the missing components I need to really bring it up properly. Notably, it uses a unique typewriter that's going to be a nightmare to replicate, so I'm still holding out hope that I can find the original. But, I'm also tossing around ideas about how to replicate the original typewriter with a more common TTY like an ASR.
I love resurrecting old electronics.... but I have no idea what I'd do with a computer like that once it was working........ so I stick to Stereos, guitar amps, and jukeboxes....... stuff I do know what to do with.
* Always replace the wet caps and do more looking BEFORE trying to fire up vintage gear, you can fry it more! Also there looked like a cut/missing jumper wire near the resistor. Your transistors on the power supply are also suspect, might test them before toasting the supply. Beware booting with unpowered things connected, they can become a big resistive load, and fry the main board.
Ken has already been helping a bit with this one, and I'll bug David WIlliams about it whenever he resurfaces on our Discord group! Not gonna lie though, I really wish I could have stolen the whole thing from Aaron and brought it home, haha.
Anyone ever imagined what would have happened if Centurion hadn't died/bought up/fused whatever happened to it? If they had been able to compete with IBM and then Microsoft? And were still making computers today? A Centurion graphical OS, mostly backward compatible with its own legacy machines/code/software? More competition in the market; a fan or officially created CosBox for truly incompatible text only software? Games created for the systems?
It's possible they would've gone over to x86 or POWER like pretty much everyone else has, rather than maintaining their own architecture. I'm guessing x86, seeing as that's pretty much what everyone uses except IBM.
Those transistors in the Terminal PSU gets really hot... the pcb seems to be damaged from the heat... maybe the super heat is an indicator of malfunction? toghether with the fact of the burnt resistor...
Interestingly, I'm starting to think this is a thing common to the ADDS Regent 40. I have both a Regent 40 and a Regent 100, and the 100 has no burn-in, but my 40 has even worse burn-in than this one. Perhaps the CRT uses a slightly different phosphor or something in a cost-saving measure.
Oh no, it's not just that resistor that looks burned up on that terminal power board. There's a lot of discoloration on that thing. Looks like it's had a very very bad experience in the past.
My hope, once we discovered the Finch had a short on it, was to boot to the WIPL on the floppy in the drive he had, but with that Qume drive having a short on it as well, we couldn't get anything to boot at all. I think most likely, long before Aaron picked the system up, something happened like a lightning strike or bad plug caused a spike that took out the Finch 5V rail, the Floppy 24V rail and the terminals PSU. It's a little rare to have three power related failures simultaneously, so I'm definitely thinking there was an external force at play here.
Ah, man... it feels like Centurion were SO DAMN CLOSE to competing with IBM for the "PC space" but they stuffed up somewhere and then IBM came and dominated everything! But Centurion were SO FREAKING CLOSE!
How computers should be. By what 1983? even before that. Mostly stuff was mfg for easy swap or replace in cards or easy repair of cards. That trend followed into desktops. Esp. workstations and servers. But, mostly failed in the laptop industry. It is a shame really. On the other note. What other Centurion will show up. :)
Yup! But, that was also kind of the point. The goal was to give users a full on minicomputer in a box almost the size of a PC. I think it's a really awesome system, and have been hunting for one for a while now!
I cracked up at “that’s why I wear pants”
Its online for 2 min
@@haudiweg unless one is a patreon supporter
Haha, I was hoping someone would catch my top-tier pun!
@@haudiweg As Ran-tan-tan said, Patreon supporters get early ad-free access!
I had to think about it for a few seconds. Well done.
Watched the other guy'd episode, earlier today. I love seeing this collaboration. I love this kind of "industrial archaeology". It is so reminiscent o the early days of rescuing the inland waterways of England (a.k.a. canals) and/or defunct steam engines being broken by scrap merchants. Future generations will be so pleased that you guy have done this, today. I wish I could ind such things here in the UK. Nothing survives!
If you can find like-minded people there's always a chance. The Data Museum in Denmark is run on a volunteer basis by an association set up to do so. Might serve as a model for the UK as well - if the railway people can do it, so can the IT crowd.
I just bought an industrial pc (sbc with backplane) from uk for 45 pound. I don t know the cpu yet, nor if it works. probably just a pentium, but hoping for 386 😂
ok, thats 90s tech not 70s... i admit
Thank you so much!
I find this stuff really fascinating and I'll do what I can to keep these old pieces of history up and going. There is quite a bit hiding out in the UK, it's just a whole lot harder to find it seems. I have a buddy there who has a decent collection of large scale machines that he's hoping to bring back as well!
I discovered this Centurion because youtube came up with a video of Vintage Geek. I
recognized a centurion terminal send a reply with a link to Usagi Electric. Nice to see you found each other. 😀
I'm so glad y'all pointed him towards me and me towards him, we can another one of these old machines up and going!
I love these old computers, never heard of a centurion before this channel. Keep up the great work!
Thank you!
Centurion very nearly got lost to the sands of time, but I'm glad the community has come together to bring this little bit of minicomputing history back!
@@UsagiElectric No problem! I am trying to get my own vintage computers, but no luck so far. Have not checked desert industries, or goodwill. Really hope you can find more Centurions or more Centurion OS.
I love the sound and the warm air from the blowers in Minicomputers.
Minicomputers are so much fun, they really engage all the senses!
That smell of dust warmed by old components and then pushed out by fans well beyond their expected service life! I resurrected a few DEC machines back in the early 2000s, and it was such a joy when they came to life.
When I see a Usagi video I always click. Love the computers, the history and the journey!
Thank you!
so you see a rabbit video? lol
You seem to have become the only support for a centurion system.
Keep it up, fantastic to see. Got to keep the vintage computing running, there is so much to learn from it.
Thanks!
And becoming the go-to support guy for Centurion is something I will happily be! I'll keep working to get as many of these old systems up and going for others to experience.
Usagi Engineering is a god in the mini computer world. Love both your channels guys. Geek up the great work.
He truly is pretty And has a lot of fun.
Oh, I wouldn't say that much, I'm just trying to learn as much as I can is all!
Nice way to start a Monday morning. Your enthusiasm is warming.
Oh, finally, the bunny has been named!
Nice small form factor centurion, too! even if not in working order!
David has become my new 8 Bit Guy!
Rarely before has a double "ERROR" brought so much happiness (12:06) 😄 👍
I would put 5V across that board from a 1A or more power supply, and use a thermal imaging camera to see what gets warm. They are getting much more sensibly priced these days, TopDon do some great ones at sensible money. Another route I've done in the past is used a really good multimeter to search for the lowest ohms point, that helped me isolate a short circuit zener diode on a large (mostly logic) board from a high end massage chair.
Fortunately, I was able to bring the Finch home, so it'll be a good opportunity to test my short finding skills. I don't have a thermal imaging camera (though I should probably get one), but I do have a couple other tools that may be able to help. If all goes well, we'll bring both the Vintage Geek Finch and my Finch up together and back up all the data on them!
Also, I never thought about it, but I suppose massage chairs would have logic boards, that's a fascinating corner of the electronics world!
@@UsagiElectric Constant current power supply limited to 1 volt or so several amps constant current. a bottle of isopropyl alcohol. power up the shorting rail . throw some isopropyl on circuit board. whatever parts of board the alcohol evaporates the fastest is where the short is
Yeah, you can even buy a device now that turns a cell phones into a thermal camera for iPhone and Android. I saw it on another channel of a guy testing one of these thermal cameras on his Iphone it lookslike it a mini thermal camera that uses your phone screen and power.
@@KoolBreeze420 i think it's called a flir if i'm not mistaken.
I don't know if this has been mentioned before, but on old hard disk drives (14", 8", and early 5 1/4") there is either no emergency head retract to a landing zone, or there is a NiCd or on larger drives, a Lead-Acid battery pack that typically provides the kick to bring the heads back to the landing zone before the loses much velocity when power is removed, thus keeping the heads flying during the move to the landing zone. Old magnetic drums (such as in the Bendix G15) have all the heads mechanically fixed in position, but due to temperature variations over time, they can lose their adjustment and potentially come into contact with the drum surface. The point I'm trying to make is that I've observed you turning the spindles on old drives (like the Finch in the Micro Centurion) and the drum memory in the G-15. This act by itself can make a storage device that was previously potentially workable, no longer so, by the heads contacting the disk physically dragging across the magnetic medium, damaging it. It's not a guarantee, but it is an avoidable potential problem by making sure that there is no contact between heads and magnetic surface before moving the rotating media. Just a suggestion for the future. All that said, I really love your channel. The joy you experience when resurrecting one of these vintage machines is positively contagious. Your on-screen presence is engaging and fun to watch. Your bunnies are positively adorable! I can't wait until you dig into the G15. It is a really amazing artifact, and will certainly bring back memories of my time working on a dual-CPU, transistorized drum memory computer made by 3M (Minnesota Mining and Manufacturing) in the mid-1960's that was used for process control. The machine had an 8Kx24 word drum in each CPU, had a bit-serial architecture, and the drums turned at 3600 RPM. The two CPUs shared a single 24-bit register with hardware interlock circuitry to prevent race/deadlock conditions when the CPU's were sending messages back and forth to each other. I/O was to a 33ASR Teletype, and a large-carriage IBM Output Typewriter. Input was from a huge bank of counters, digital to analog converters, and comparators that could be used programmatically to also function as analog to digital converters, as well as a real-time clock (Parabam transistorized clock using projection displays), input from the Teletype and Teletype paper tape punch, and a series a thumbwheel switches that could be read under program control. While I had access to the machine, one of the 8K drums suffered a bearing failure, and crashed the spinning media into the heads at speed, causing its total failure. The timing for the CPUs came from dedicated tracks on the drum, so the second CPU we no more. But, it was still great fun writing programs for the original master CPU, which ran for the entire five summers I had access to it (at the local High School, which the machine had been donated to by a local utility company). Programming was interesting, because each instruction contained both the operand address and the next instruction address, and in order to get maximum performance, you had to calculate both addresses by taking into account the rotation of the drum to allow quickest access to the information without having to wait for the drum to undergo another revolution. I'm sure you'll run into something like this with the G15 when you get it running....and I know you will! Best of luck in all of your computer restorations, and keep up the fantastic work with the videos. Sincerely, Rick Bensene, Curator, The Old Calculator Museum oldcalculatormuseum.com
Try getting through security in Myanmar with a suitcase packed full of fuses the size and shape of dynamite sticks and other various electric components and wires. And no one speaks English 😨 "Mingalaba" didn't work, I can tell you that much.
I love these videos where two (or more) of my favourite youtubers get together and do a video! Thumbs up for that, and for you always being so helpful to people all around the US 👍
Hi from Knoxville,TN! My hometown.
Crossover series! Now that should be fun! I saw the Centurion on his show a few weeks ago and I was one of the commenters pointing out Usagi Electric.
As an april fool's prank, you should do this again, but end up with like a centurion toy or something.
Hey! A SYCOR!! At 1:59 on the right.
The museum is located in Knoxville, TN, USA. They only mention it at the very end of the video.
Thank you for using DE9 instead of the DB9 misnomer.
Great episode.
Perhaps you can get the machines to talk UUCP and mail between each other one day.
I started watching this channel because of my grand dad as he really relates to these old vintage computers. And to be honest, I have really enjoyed watching this series with him. With his help, I can follow along and understand what is going on and I find these videos about the Centurion fascinating. I hope that you have not forgotten about the printer restore. That might prove to be quite challenging I know, but you have managed to have a lot of really smart people help you with getting things working, and we here know you will eventually get that printer working too. Oh and the Phoenix hard drive! Don't forget that one! Today, the new tech just doesn't leave much to the imagination, but somehow the old stuff seems to open up an endless variety of possibility. Hard to explain. I have learned a lot watching, listening and reading comments. I am grateful.
every computer you are allowed and can repair yourself is a good computer, its 100 times better than one of those super slim sandwich ones.
I like shorts! They're comfy and easy to wear!
At least with the drive dead (as a short) there's a chance there is still the os on it. Shorts are relatively easy to fix, lost os or programs could be a bit more difficult to replace.
My favorite part of these episodes is seeing the bunny
if I had put up and kept all the stuff I tore apart when I was growing up id have my own little museum. if only I could go back in time and tell myself to just keep everything. I'm sure my younger self would just give me the finger and go right back to it lol.
I thought that was only me. I destroyed so many electronics taking things apart, I kick myself to this day. One of the best was a handheld Defender game with a colour VFD that ran on 4 C cells. That was such a fun game. That was almost 40 years ago and I have never seen another one.
Thank you for sharing. I use a Keysight bench meter with good quality four-wire Kelvin probes to find problems like shorted bypass capacitors - which I’ve had to do more than once. A regular Fluke meter may not be sensitive enough to spot a short. It beats having to unsolder or clip out capacitors. Another strategy is to apply current-limited power and then use an infrared thermometer to spot the unexpectedly hot capacitor. Owon makes some acceptable and affordable bench supplies which allow both output voltage and maximum current to be set. There are both switcher and linear models to choose from.
I love this channel. While they ran into a lot of trouble on this particular outing, I find these videos so soothing to watch. In a world that seems to gone mad, it’s great to relive some of the good old days
Sounds like a power spike took out the power rails, and just fused the first thing it could. That was the 5V in the Finch, the 24v line in the PSU, and obviously something funky in the terminal. Could well have been backfed power through the ground, maybe a faulty appliance pushing current through the metal cases?
I really dig the case design of this one.
Me too!
I really want to build a replica (or even better, find another one). It's a really smartly designed case that has a great form factor for using on a desk.
I passed through Knoxville twice last week. If I had known, I would have convinced my wife even more of my Geekness by stopping by.
Awesome. I was hoping this meeting would happen! 🎉
I've manged to narrow down the location of shorts on power rails using an accurate multimeter in resistance mode (eg EEVBlog BM235 or your Fluke meter).
Probe in multiple places to get all the readings that aren't zero, eg 0.3ohm, 0.2ohm, 0.1ohm. You end up with a map of where the short isn't, in the center of those 0.1ohm readings is the fault.
lets say there are 5 chips in a row, and the outer two are 0.1ohm, well the chip in the middle (3rd IC) is the shorted one.
ps: The axial caps with the metal can and transparent cover that are almost certainly branded Sprague, are Tantalum Caps, possibly just one of those shorted.
Guide to locating shorts on boards in general:
Solution A: Get a really good multimeter with lots of precision, and measure your way towards the short as the resistance goes lower. This works adequately and is very non destructive, but sometimes the short isn't technically a short, but rather behaving a bit like a diode and needing some voltage to get going (typical of some ICs), then things get harder, since most meters considers it fairly high resistance, so one can walk straight past it...
Solution B: Apply a suitably low voltage and look around for hot components. This too can be tricked by faults that needs some minimum voltage to appear, but one can slowly crank up the voltage towards what the rail is supposed to have. Just have a current limit on the PSU, and remember that SCR latch up is a thing, so sometimes this can kill ICs, especially in older equipment, so I would go for full rail voltage to start with, if you are lucky the short simply goes pop and you now know where it were.
Solution C: One can also just poke around the board and compare it to a known good board. But then one needs a known good board, something you seem to have so this is a decent path. However, for power rail shorts this often becomes, "the power rail is shorted, else the two are measuring identically." so this method isn't really that good for this kind of fault.
That is really interesting. We never had any credit unions as customers in the Cincinnati area in the 1985-1986 timeframe. I wasn't as familiar with Cruze's Knoxville customer base, but I don't remember any mention either. So I've never seen one of these.
EDS's own sales teams sold most of the MicroPlus systems not the Centurion dealer network. EDS was selling the MicroPlus mainly to CUNDATA Credit Unions.
... and the Finch should not fly until all wings and feathers are all checked!
always like the old stuff.. like imagine a 2.5G RAM memory system with 500 core CPUs and a bunch of big platters and tape drives in some USAF cave from the late '60's...
If you're interested in a cheap solution for a thermal camera for tracking down hot chips, you can get thermal camera attachments for your phone for reasonably cheap.
They're not exactly great compared to a dedicated thermal camera of high quality, but they're still more than good enough for tracking down bad chips.
Wow, finally an excuse to dig into the Finch drive 😂, hoping for the troubleshooting video soon
Get a IR camera. That makes finding shorts in pcb power boards much easier.
I really should, and the prices are indeed coming down, maybe this will be a good incentive to finally pull the trigger on one!
@@UsagiElectric I first used an IR camera at work. Latter I bought a FLR camera that plugged into my android phone. That worked well. It combined the visual and IR image so it was easier to understand what you saw. But there was a problem. When I bought a new phone it wasn't compatible because it wasn't type C. So I bought a stand alone IR camera from Topdon TC004. It works well but doesn't have the visual image. It also has a threaded hole for a tripod mount. Good luck.
Yup! When I worked for an avionics company, we had a really nice Fluke brand IR camera. And it was almost just for pointing at a PCB to see what got hot. Great use for a $20K camera!
That intro is pretty great
Down the Centurion rabbit hole as the Centurion world expands!
I always get confused when someone says a MUX. My brain goes into confusion mode. All it means is a multiplexer. Why does my brain do this. Love your work guys.
I suppose it's really a serial UART card for the data terminals, but Centurion wrote "MUX" on the pull tab, so that's what I always call it!
@@UsagiElectric Usagi I love your videos. You are an inspiration to me. Keep up the great work.
There goes another satisfied customer.
I watched Aaron's video yesterday. I guess it was a lot to expect everything to just work! You have some work ahead but I am confident it will all work out.
I had a chuckle when you stated that you have three out of five known Centurion machines. There could be some other examples sitting in dusty warehouses or abandoned buildings, which is a bit sad. Most likely they will end up in a scrap heap.
Another method for finding where a short lives that does not require an IR camera is to hook the board up to a current limited power supply. Set the limit at around 1 or 2 amps. then start measuring voltages across Vcc - GND. Away from the short this will be a few millivolt. Closer to the short it will decrease to zero millivolts. This does require a very sensitive voltmeter though (and verifying that nothing is heating up).
I'd start with a lower current than 1A, but otherwise agree.
Yeah this will work with a much less sensitive meter than what it takes to locate a short via resistance measurement alone
You made it to the next bug! Progress!
I live in Knoxville, I need to make it over there.
Nice adjunct to the earlier Vintage Geek video also today...fingers crossed but I know you guys can do it!
We'll definitely get there! We knew from the start that the Finch would give us grief, I have a terrible track record with CDC drives, haha. I was surprised the floppy tripped us up though. Fortunately, it's a fairly common 8" DSDD unit and even if we can't bring that one up, we can always slip a replacement in there.
I think the beard is coming back !!!
Slowly but surely, it'll be full wolfman before we know it!
I'm still intensely waiting for the next part of using Neons to make logic gates
They have Mario and Luigi energy.
That big ass cap needs a trip to tech tangents reform school.
Very, very interesting computer, and something to learn! How to pack huge low integration ic boards into a pc sided desktop. I thought it's impossible.
So cool, what a find! I was in Nashville last week nooooo
Shorts tend to happen in power circuits. Either the regulator, or the output stage of whatever drives the heads or spindle motor. It's less likely to happen on some random TTL chip.
Which is why you totally isolate the supply from anything else before randomly powering up and blowing the snot out of something important..
@@ingmarm8858 Which we did. Just because it didn't make it into the video doesn't mean it didn't happen. We powered up the supply completely empty and nothing bad happened but the rails were good, so it was kind of boring to show. Then we plugged in the floppy the main PCBs. The floppy having a dead short on the +24V rail is most likely what caused the pop.
Lol the camera fainted from the fear
So exciting!!!
Its usually possible to find a shorted tantalum cap with an ohm meter. You should see the lowest resistance across the shorted cap and a nominally higher (but also low) resistance across the good ones.
A marvel of space utilization. Too bad that both drives had issues but not that surprising. No one that designed or built them intended them to survive 50 years.
Awesome news that another Centurion has been found! Fingers crossed for getting that drive running. I've one question though, what's the rabbits name? ;) Great video - highlight of my evening to see it appear in the feed.
Thanks!
I usually show about three different rabbits in the end, but the one shown in this video is "Kome," which is Japanese for "rice." Unfortunately, she passed a couple years back, but she was our little adorable rice ball, haha.
The other bunnies I show are our current bun "Koma," which is Japanese for "troublemaker" and "Kono," the light brown bun I show on the occasion, who was our very first bun when we were living in Japan.
@@UsagiElectric thank you. They are adorable 🐇
My father designed and built the thick film hybrid memory modules for General Automation minicomputers. Is this something of interest to you? Maybe you know someone who might find this interesting?
What do you have from his work?
Didn't know about this place and it's only a couple miles from home.
Hey David, please do not forget Litton and Bendix machines!
Heya!
Working on a Bendix episode right now, it'll be going up next Sunday!
The Litton is on pause while I hunt down the missing components I need to really bring it up properly. Notably, it uses a unique typewriter that's going to be a nightmare to replicate, so I'm still holding out hope that I can find the original. But, I'm also tossing around ideas about how to replicate the original typewriter with a more common TTY like an ASR.
I saw a video like this yesterday already.
I love resurrecting old electronics.... but I have no idea what I'd do with a computer like that once it was working........ so I stick to Stereos, guitar amps, and jukeboxes....... stuff I do know what to do with.
Sell it for gold/rare metals.
Just came for the munching usagi ❤
In future you should probably drive to Tennessee in Future.
I really like your: 4 hours later... I know very well how that feels. But it fuels: We don't give up... until we see 'ERROR'. Congrats!... to: ERROR.
* Always replace the wet caps and do more looking BEFORE trying to fire up vintage gear, you can fry it more! Also there looked like a cut/missing jumper wire near the resistor. Your transistors on the power supply are also suspect, might test them before toasting the supply. Beware booting with unpowered things connected, they can become a big resistive load, and fry the main board.
Wait, , What???? there is a computer museum literally 10 minutes from me???
I drove by there three times today and yesterday on errands,
nice job
I saw the video on the other chanal
you doeing some good work
Cheers!
Another winner from Centurion, maybe some of the old timers will check in on this on, Ken Romain, and David Williams are you guys still around?
Ken has already been helping a bit with this one, and I'll bug David WIlliams about it whenever he resurfaces on our Discord group!
Not gonna lie though, I really wish I could have stolen the whole thing from Aaron and brought it home, haha.
@@UsagiElectric That would pretty well round out your product line if you can talk him out of it...
Nice
Thanks!
I could see were TSA would see the drive as a IED
Anyone ever imagined what would have happened if Centurion hadn't died/bought up/fused whatever happened to it? If they had been able to compete with IBM and then Microsoft? And were still making computers today? A Centurion graphical OS, mostly backward compatible with its own legacy machines/code/software? More competition in the market; a fan or officially created CosBox for truly incompatible text only software? Games created for the systems?
It's possible they would've gone over to x86 or POWER like pretty much everyone else has, rather than maintaining their own architecture.
I'm guessing x86, seeing as that's pretty much what everyone uses except IBM.
I wish I was closer. I’m in Memphis. Also David where do you get your great TShirts?
Those transistors in the Terminal PSU gets really hot... the pcb seems to be damaged from the heat... maybe the super heat is an indicator of malfunction? toghether with the fact of the burnt resistor...
That model of ADDS terminals with the vert. mounted power supply failed often. We repaired the ADDS power supply more that other ADDS PCB's.
5:37 I notice that the CRT has some bad phosphor burn-in.
Interestingly, I'm starting to think this is a thing common to the ADDS Regent 40. I have both a Regent 40 and a Regent 100, and the 100 has no burn-in, but my 40 has even worse burn-in than this one. Perhaps the CRT uses a slightly different phosphor or something in a cost-saving measure.
Cool.
Oh no, it's not just that resistor that looks burned up on that terminal power board. There's a lot of discoloration on that thing. Looks like it's had a very very bad experience in the past.
did you try booting from the bootable floopy you made a while back?
My hope, once we discovered the Finch had a short on it, was to boot to the WIPL on the floppy in the drive he had, but with that Qume drive having a short on it as well, we couldn't get anything to boot at all.
I think most likely, long before Aaron picked the system up, something happened like a lightning strike or bad plug caused a spike that took out the Finch 5V rail, the Floppy 24V rail and the terminals PSU. It's a little rare to have three power related failures simultaneously, so I'm definitely thinking there was an external force at play here.
Still cannot beliefe you did not fasten your seat belt.
I can't wait :)
Ah, man... it feels like Centurion were SO DAMN CLOSE to competing with IBM for the "PC space" but they stuffed up somewhere and then IBM came and dominated everything! But Centurion were SO FREAKING CLOSE!
YES but can we get it to run doom
Pov : you have a centurian ediction
👍
Keep up
👌👌👍👍
1T4
How can a computer be advanced coming from Tennessee.? You should have picked a state that was out of the dark ages.
14:10 but what's that machine on the right? A very odd form factor.
Looks like a Sycor 340 Intelligent Communications Terminal.
In case of apocalypse else know who to trust to retire humanity
How computers should be. By what 1983? even before that. Mostly stuff was mfg for easy swap or replace in cards or easy repair of cards. That trend followed into desktops. Esp. workstations and servers. But, mostly failed in the laptop industry. It is a shame really. On the other note. What other Centurion will show up. :)
Due to the time crunch, I took a dremel to the screws and shorted out the PSU with a paperclip. XD (yes, 8-Bit Guy is still good joke fodder)
Intersting box. Like a PC, but not.
Yup!
But, that was also kind of the point. The goal was to give users a full on minicomputer in a box almost the size of a PC. I think it's a really awesome system, and have been hunting for one for a while now!
Слишком короткое видео((((
whee. w hee :)
why vow? why would it make someone believe in you more? what the use in that?
it will make "honest to God" believe in you even less