Power electronics engineer here specialising in MRO of rail power electronics. You're cleaning the boards exactly how I would, only think I would change would be to add Isopropyl alcohol to sterilise and act as a drying agent.
Some old capacitors wouldn't be happy with much time with isopropyl. Polystyrene capacitors will degrade. I have also had cases of it attacking coax cables. The insulation between the center conductor and the shield seemed to soak up the isopropyl and distort.
I this case it's more of a rinse instead of a soak in the IPA though, right? Just enough to help get rid of any residual water and unwanted microbiome...
Sadly the computer doesn't support CAT-5, because it would surely need some to get rid of the rats. But at least the rats keep hardware bug from creeping up.
Your portable ADDS terminal has the same 3 main PCBs and keyboard as the ADDS 580 used in first Warrex CPU4 systems. The one with the side connector is the FE card ( has the RS-232 I/O logic ) the middle card is the screen memory display buffer ( the display buffer has 9 shift-reg IC's, 1-3 for first 8 lines, 4-6 for the second 8 lines and 7-9 the last 8 lines = 24 lines x 80 columns ). The two main issues are the FE card RS-232 I/O chips SN75188 & SN75189 and on the screen buffer card the 9 memory shift-reg. chip house 2 bits each by 80 positions on the display. The normal test for bad shift-reg chip is to type in 1/2 dup. A B D H P (return) in all 24 lines on the display. A B D H P will turn on a single bit on the ASCII code of the up-case only ASCII display. Many times the A B D H P typed will be displayed as with a extra or missing bit so the A B D H P displays the wrong letters.
would the Envoy work on the centurion(or is it beyond 24x80 ability?) ( your other comment notes the probable failure for the chips - try a card swap between terminals first ?) Presumably CRT in the rat one is power supply related and solvable ?
@@highpath4776 The ADDS Envoy will work with the Centurion system(s). The ADDS Envoy terminal is a re-packing of the ADDS 520 & ADDS-580 that we used at Warrex (Centurion) in the mid 1970s on the CPU4 system.
@@russellhltn1396 Correct the RS-232 lin driver & recv. IC like the SN75188 & SN75189 ( or 14188 & 14189 ) failed often after lightning storms within miles of the computer system. The long RS-232 cable from the computer to the terminal acts like an antenna when lighting is in the area and blowout the RS-232 I/O ICs on the terminal ( and also the Centurion 4-Port MUX card ).
Good luck finding the Static shift register chips. It was the reason ADDS stopped production of several lines (580/880/980/620) Then the regent series was produced followed by viewpoint. The video memory card is sectioned by 3 groups of 8. abdhp is only need once per section not all lines. Check test key -L clear screen abdhp -K K abdhp -K W abdhp . re: ctrl is control key, space is space bar. The space is important. Any bad shift registers will show as a @ sign. FYI -K was direct line access @ line 1, W line 24
Just saw the part of the video showing a large number of ((( ( (( ( in a field of what should be ASCII spaces. I would bet the ((( ( (( ( because the error in the raster display is in the middle grouping of 8 lines the issue is with the ADDS memory shift-reg card's 9 Shit-Reg. ICs, one of the chips is flipping bits because it's just bad, ( This was a very common problem and many time was heat related. ) Space code = 0x20 and the ( code = 0x28 looks like a bad shift-reg bit.
Ken swinging in with the proper expert diagnosis! Gonna have to get you down here to help get this thing and the printer fully up and running one of these days!
To get the keyboard loopback working, you might have to assert DCD to the terminal; on the VT52-like terminals I used, you could loop DTR back to DCD; on those terminals, DTR was an output that would be asserted when the terminal was "online". We would also wire those two to the DSR pin. You may also have to loop back CTS to RTS if the terminal requires a hardware handshake.
"A switch here that says 'modem' underneath it - I have no clue what that does." Pretty likely it selects between the acoustic coupler and the data port. It's not clear if this was actually set correctly through the serial experimentation. I also suspect the rear BNC is for connecting an adult-sized display. I'm actually surprised more of the protocol controls aren't on the front panel, given it's a luggable terminal for working in the field.
Thinking the same thing for the BNC Jack. Otherwise I can't make sense of it. The number of things that video output is not a standard on when it has a built-in display is so annoying. oh and @iroll you're right I hit the timestamp and immediately went AAAAARrrrrrrrrrrrrrrrrr.
"Modem" position enables the acoustic coupler and built-in 103-type modem (good to 300 baud). The "up" position routes the data path to the RS-232 subD connector and allows you to use the faster baud rates for direct connection to your computer (or a faster modem)
The "carrier" light would be for the acoustic coupler. Remember how, in the days of dialup connections, if the connection dropped you'd get a "NO CARRIER" message?
@@UsagiElectric as mentioned in some other comments I have an Otrona Attache portable computer that is about the same overall size as the ADDS terminal but I think the crt is larger and it has two 5.25" floppy drives. But no built-in acoustic coupler/modem. It could even run from battery using a separate power pack thing. I've never seen the power pack. In the early 80s I did some programming for building energy audit software at a place that was selling it to utility companies after a federal mandate required them. They were marketing it with either Compaq Portables or the more compact Otrona. The "base" Otrona ran cp/m on a z80 but most wound up being sold with a PC compatibility card that ran a slightly modified DOS 2.1 on an 8088 or 8086.
This has to be the most psychedelic portable terminal I've ever seen (and I've been messing with computers since the late seventies). Good job using all your available resources. I look forward to the part two.
24:36 oh that beautiful CRTs Sound. I believe I'm watching in 480P and as soon as the switch is hit that beautiful glorious high frequency noise somehow was not compressed out of the A/V stream.
Your picture of the Digital brand computer brought back a memory I had forgotten. In 1995 I got a job selling pc's at Sun tv and electronics, long gone now but think Best Buy. We sold several brands of pc's and one of the better ones was the Digital brand. One day we get in a new shippment and we put 2 out on display. About 2 hours later we look over and the damn speakers were on fire on the first one. We get them unplugged and about that time computer two's speakers are smoking. Took them all down, back in the boxes with the charred speakers! don't know what happened but Digital disappeared from the store!
freeze frame at 3:26, this is the stare your father gives you at the dinner table when you tell the darkest most nauseatingly offensive joke that makes your grandma vomit, your mother choke, and your step brother piss himself laughing all at the same time
On the capacitors you're measuring the raw unregulated DC. this is typically higher and perfectly normal, especially when not under load To be a regulated output in fact it needs to be higher. If you measure the voltage at the actual output that then goes to the electronics you will find your expected normal voltages.
The large capacitors in a linear power supply are most always pre-regulation. So those voltages you got are fine. The 13v regulates down to +5 and the +/-27v regulates down to +/-12v. They will also go down when the supply is loaded but you can see the headroom built into that power supply. I should also mention that the large capacitor in a line operated switch mode power supply is more or less tied to the AC line. So don't attach any test equipment without using an isolation transformer.
Well, now you have a spare parts machine with an aroma. :) I think you mentioned that you have an ultrasonic cleaner but not a large one, and that could help to really sanitize those parts. Might I suggest setting up some kind of fund-a-large-ultrasonic-cleaner button or page. I would contribute to that.
Some put them into dishwashers so your approach is positively gentle in comparison. The output you see is caused by 3802 and 3809, but you'll find that soon enough :)
In the early 1980's I worked at a Chuck-E-Cheese's and we would pull the main boards out of video games and run them through the industrial dishwasher to rid them of spilled soda and "goo". They worked fine after some compressed air + drying time. 👍🙂
Imagine if any of the companies making luggables would have turned theirs on the side, rotating the CRT to sit up high, what a revolution in ergonomics it would have been.
A perfect way to clean is, besides using a mild detergent, distilled water as it is mineral free and thus non conductive. A 100% dry out is to set and oven to its lowest temperature i.e. "warm" (pre check the oven with a thermometer) to fine adjust, leave the door slightly or fully open. At a temperature of around 125-150F and a small fan blowing air inside, place the cleaned item to be dried inside for a few hours. Any water residuals will have evaporated! Worked wonders for me! Dried out any device including Mobile phones! Thereafter spraying/soaking all in Water Disbursement Formula 40, widely know as WD40, does wonders!
Wow, I hope you show up at VCF East, but I do understand that is too long of a drive for you, especially toting all that stuff. It was great seeing you there last year.
@@Daveyk021 plenty of other shows and show and tells to be done. Presumably awaiting rest of Centurion build and the Bendix for the computer museum to be put to bed first
I am very much so attending this year! I just won't be displaying anything. Last year was epic fun, but I didn't actually get a chance to see the show. So this year, I wanted to make sure I got a chance to go around and see and talk to the other exhibitors!
(28:00 "in half-duplex," keyboard characters should echo locally, is what I think you meant to say.) Anyone's guesses on whether that Modem-Up-arrow toggle changes polarity for DCE-vs-DTE? THANK YOU!!! I just looove interesting terminals, and this little guy is just gorgeous to look at! -and I've never been brave enough to try Simple Green on electronics, thanks so much for your advice on what typically is and is-not safe to use the cleaner on.
Is bridging pins 2 and 3 enough, or should you be connecting RTS / CTS and all that? A proper dummy plug. Maybe connect the terminal to a PC so you've got decent control of the other end. That coax plug at the back looks like a BNC, and I'd guess it's an external monitor socket. The fact that the top of the terminal is flat also hints at that, that you'd use an external monitor back in the office. You could check if it connects near the video generator internally. It's not like the terminal would be put in a cupboard when you're not travelling, it was expensive! So you'll likely have been using it at the office too, with a proper monitor. Probably just standard composite video. Really want to see this thing working, keep it up!
I think you meant "mouse" instead of "rat". That smell is unmistakeable and vile. You did not waste time cleaing up both systems as you may needs parts/cards from both to make a good one. IPA is a good drying /sterilizing agent after simple green as was already suggested. I have a dehumidifier in my basement and crank it up with the boards surrounding it after a good going over with compressed air. Also a good idea to remove any socketed ICs and use compressed air - water gets trapped in those sockets.
A couple of things here: 1) Be careful with the CRT board and CRT itself. Those run on VERY HIGH VOLTAGE. The CRT Anode and flyback transformer outputs could be in the thousands of volts! Even the grid drive runs in in the 30-200 volt range. You may want to use an isolation transformer when troubleshooting it. 2) The Data / Modem switch might do one of several things. I suspect that it may control whether it operates from the accustic coupler or whether it operates directly from the DB25. It could also control whether the output is full duplex or half duplex. Early terminals did sometimes connect over phone lines to mainframes. Others were directly connected. Likely this reflected whether they ran cable or connected from another office. 3) The Linefeed settings could reflect which type of computer you are connecting it to and whether a return is a carriage return, a line feed, or both. Different computers handled this differently. Again, this might also set which type of terminal interface the mainframe you connected it to used. Different models used different interfaces. Examples of some of the terminals protocols included VT-100, ADM-3A, VT52, D1, D2, D3, Televideo 910 through 9150, VT220, ANSI, and others.
Thankfully, i had dinner about an hour ago. Never seen so much rodent poop inside electronics and i certainly have seen some in my life. Btw. which brand is your editing monitor? Just curious, because the aspect ratio looks quite unusual to me.
It was definitely rough inside! The editing monitor is an ASUS VZ239H-W, just a standard 23" 1080p monitor, nothing fancy. Perhaps the 50mm lens I filmed with made it look a little weirdly shaped.
It was from the episode "Computer Killer" of the original "Hawaii Five-0." The bad guy uses the Envoy to remotely connect and hack into all sorts of fun stuff!
Can't tell you how many times I've dredged through poop only to realize there was an easier way. Usually had to do with my marriage more than electronics but you know.. You live and you learn. 🥴
About your method of cleaning the boards: Is there any OTHER way of cleaning electronics quicly and reliably? From what I know, water does no damage whatsoever unless they are operating.
It's not the water doing the damage, but whatever minerals are dissolved in it, which get left behind as a coating that might short stuff out after the actual water evaporates.
Back in the day they would often hose down boards with Freon 113. It works great for cleaning circuit boards. Unfortunately, it's not so good for the ozone layer. Deionized water is fine for cleaning boards. It won't damage most components and doesn't leave residue behind. Tap water will leave mineral residue that can potentially cause issues.
6:15 Mouse. That's mouse poop. Rat poop is a LOT bigger. About the size of your pinky fingertip. Source: I have pet rats. Not particularly relevant, but rats and mice behave differently, plus you really can't underestimate the size difference. Rats are absolutely MASSIVE compared to mice.
Domesticated rats actually make really good pets. They're very intelligent and friendly. I had a pet rat a long time ago, and it was amazing how friendly he was. He loved to climb up on my shoulder and eat sunflower seeds lol. He loved to be held and petted too, and one time he even fell asleep in my hand!
You're totally right, I don't think a rat could have comfortably fit inside of this thing anyways. I've seen a few proper rats in NYC, and you're right, they're massive!
@@ct92404 Mine like to come sleep with me on the couch, and two of my girls like to sleep in the blankets with me. One was an escape artist and would open the cage door at 4am to come find me and crawl into bed with me. They aren't called pocket puppies for no good reason.
Might think about getting an ultrasound cleaner. No complaints on your well reasoned cleaning method though. I imagine that thing when it heats up is going to "share the joy" for a while till it burns off completely 😅
Yep - Ultrasonic cleaning would do a lot. A lot of people, myself included, use it a lot to clean up contaminated (battery leak, fluid spill) and/or corroded circuit boards. Keep in mind that older electronic parts can be dried out and cracked over time, so that can be a problem. They should be replaced anyway, but thorough inspection and checking is always needed.
You never know what you'll get on the Usagi Electric channel. Vacuum Tube computers? Insanely loud printers? The Last of Us? Everything is on the table!
When I worked for Tektronix we washed 99% of stuff coming in for repair. Then it spent a couple (or more) of days in a drying oven. sorted a lot of problems out and made many look like new. standard procedure.
To add one nugget to the cleaning bit- It's a good idea to be careful with wire harnesses in addition. Water can wick several feet inside the wire insulation and can stay there. This can cause issues in the long-term on some wire types. It might also be a good idea to hose the boards off with distilled or de-ionized water as a final wash so that it doesn't deposit minerals on the boards during drying.
hope you checked the voltages on the second machine? that picture came up suspiciously fast, if its getting too many volts it'd cause that, check crt heater volts , these sort of tubes are usually 10 to 11 v
I like when he does that. My take for a long time has been, "it's already broken, whats the worst that will happen? It will be broken when i'm done?". Funny enough, things get fixed faster that way because you don't waste time thinking about something 2x longer than you need to because of fear of breaking it.
The rat machine might not be permanently out of the picture. Would it be possible to sub the CRT module from the clean machine into the rat machine? If only to give the rat machine a second chance to show something? In order to better deodorize the rat machine parts, perhaps a dunk of each board for a few hours in some Nature's Miracle or equivalent enzyme/bacterial product from a pet store might be helpful. An emanation of especially pungent ammonia odor is good news here, for it means the waste is breaking down, releasing its nitrogen. (Sometimes a situation has to stink worse before it ceases stinking.)
Didn't feel like too drastic a shift of gears to us -- with the goal of getting a nice portable terminal, it's all part of the same project, and we can enjoy the process of discovery/realization right along with you! I have a feeling the "smelly" machine will prove more useful in future diagnostic efforts now that it is clean as well.
Yeah, I don't see cleaning the now-parts-machine as a 'shift in gears'. You rather expect twists and turns with projects like these, all the while holding out hope that the 'parts machine' may get a fresh keyboard one day too :)
I restore pinball machines and also have a lot of nasty boards and electromechanical parts to clean up. I suggest getting yourself a 10-22L ultrasonic cleaner (they're surprisingly inexpensive) for future projects. A 50/50 mix of Mean Green and water does great. Next, a quick rinse under the tap and then the air compressor to blow out any water. Lastly: this works great for coils and transformers too! After their bath, they sit in a tupperware container full of silica gel beads for a few days. Overall, it's much gentler than using a brush, and the ultrasonic gets to every last nook and cranny. I've had many crusty barn find come out of the cleaner looking like it rolled off the assembly line.
You can absolutely wash electronics. I've seen Tektronix and Fluke service manuals, where they discuss how to clean boards with water and detergent. Some Tek scopes have water sensitive components and they are labelled as such with the instruction of removing them before hosing down the device. SO you are 100% right with wahsing the grossness off.
PCB assembly houses often will use what is essentially a dishwasher, just with no boil cycle, and drip dry, and regular dishwashing powder, to clean new boards after assembly. Big volumes they have a big machine, but small runs just a regular dishwasher is often used.
@@seth8629 Because the phone has a charged battery in it. Take the battery out, and remove water sensitive components (speaker, things that use water soluble glue, etc.) and it can be hosed down. The damage comes from having electricity pass through contaminated water, causing electrolysis and rapid corrosion. No electricity, no electrolysis or rapid corrosion even when using contaminated water that is conductive. In college as an experiment we tried submersion cooling computers to see the effects it had on cooling efficiency. Essentially to see if it could be more cost efficient and environmentally friendly to passively liquid cool computers, instead of using fans or pumps to air/liquid cool them. Turns out, no, the best form of cooling is actually just an air cooler on a big a** radiator. Guess we came to the same conclusion people did a long time ago. But, for our experiment we essentially just took a big plastic storage tub, filled it with various liquids (we used distilled water, vegetable oil, motor oil (used it in our cars afterwards), mineral oil, we even tried a couple types of alcohols courtesy of the chemical engineering department (cleaning or solvent based, not the drinking kind). Distilled water didn't cause an issue as long as we rinsed and dried the boards first, we actually tested the water throughout the test to make sure it was free of contaminates that would make it conductive so we didn't damage the boards. The only things that actually damaged the boards was the solvents, they must have eaten away at several components on the board, and we expected this. Water and the various oils however caused no damage to the board.
I worked in a TV repair shop for a while. They taught me to always wash the high voltage transformer when replacing the usual parts. We used a water with a dish washing soap. Then it was dried with a blow dryer and that was it. Why shouldn't it work? It had to. However, I recovered some phones that were sleeping with fish for a while (battery on). I think the tons of rust and electrolysis products were harder to clean up than just some rat poo. It was really, really surprising the phones started to work. I was almost confident that you can just wash electronics and it would work. But well, there was that one lousy rubber dome keyboard. After washing and drying it became absolutely dead.
@@seth8629 Partially because the phone has a live battery with a charge in it, while the disconnected circuit boards do not, and were given a proper drying before power was applied. Water and powered circuitry do not mix because it causes electrical shorts, since the water is conductive.
People that complain about washing boards have never worked in PCBA manufacturing. We run assembled boards through plain water washes every single time, it's how they are cleaned before configuration and testing. Heck, I literally spent over an hour washing boards just a couple days ago at work. Although, personally, if the board can handle it, I just bake them. Not only does it dry them out more thoroughly, if I do have to do any touch up soldering it makes that go so much better as well.
@@bzuidgeest It's literally just Deionized water, a.k.a. purified water. And we manufacture for some of the biggest companies, including stuff in your computer, so you kinda already do. Also, if you travel by plane then I hope you don't mind :)
All the Warrex / Centurion minicomputer PCBs had the solder flex remove during mfg by a trip to the Sears dishwasher for a wash cycle (without any heat dry cycle). The PCB air dry in a rack for two day the moved to a heated burn-in rack with all DC voltages ( +5, +12,-12 ) for 48 hours for being tech-ed and installed in to a Centurion system. We even ran field repair returns in the Sears dishwashers as needed. Yes the Sears dishwasher was purchased at the local Sears store in the mall.
12:57 Transformers, coils.... Don't forget non sealed relays. I've seen plenty of boards that make a "splop" noise and fail to work over the years as the relays have solvent or cleaner in them :-) I enjoyed your show and tell "shit show"
The print ad mentions a price of only $3400!! Today's inflated equivalent: about $25,000!!!!! You could buy a nice car for $3400 in 1972. Today $25,000, not so much.
Agree a nice car for $3K and a 1,400 sq ft house with 3 bedroom, 2 baths & 2 car garage for $25K in Dallas with a years pay still in your pocket in 1975. My starting hourly pay at Warrex / Centurion was about $4 per hour in 1975.
Excellent series. I haven't seen an Adds Envoy in decades. They were nearly a decade old and being sold for nearly scrap prices in the early 1980's when we were still using one. It was a much better solution than other portable terminal we had, a the TI Silent 700, for portable work in the field. I can't wait to see your whole portable built out. WOW!
I was just wondering if you were connecting the meter correctly on the capacitors, my theory is that you may have had the negative meter wire on the minus 12, that would have given plus 17 and plus 24 on load.
12:12 - Anyone complaining about washing the boards is probably not aware of the fact that to ruin electronics with water, they have to have power flowing through them. I knew this at 13, and I bet my friend $20 (that's like $40 now) that I bet this 286 motherboard that I got from school (legally - no case or anything, just the board) will survive a plunge in the bath. I showed it to him POSTing using my 386's video card and keyboard to go into the BIOS and do stuff. Then I took all of it apart, and proceeded to dunk it in a bathtub with 2-3 inches of water in it. 20 mins later I took it out, and I said to my friend to come back in a couple days. I immediately removed all the chips (this was an old sucker, lots of discrete chips) including the CPU and dried those separately. I put it all back together, got my buddy to come by, and (I tested it previously lol) it POSTed and the keyboard worked, onboard RAM (like, 10 DIP modules), everything was fine. Bollocks to the commenters who think this is a bad idea. I've since put motherboards in dishwashers to get grime off them. Just let it dry.
I had 10 units like that terminal in working order, you could have had. I donated them to my College for display cabinets with antique dumb terminals in the computer lab building that have never been plugged in? I do have a KTel 5” drive suitcase computer where the cover is the keyboard with a 6” diagonal green screen 📺
What a gorgeous 70's-tastic beast, inverted screen too. One thing I noticed through all the comms testing was that you had the 'modem' switch down, hinting that the acoustic coupler was the device of choice. Is there a chance that disables the RS232 port?
Water and a non-acidic/non-alkaline cleaning solution is actually used professionally for cleaning, so anyone who did do the angry keyboard thing needs to research. You'd let it dry and then do a bath with Isopropyl to just make sure all the water was expelled, but air drying is also a legitimate drying method for PCB's and electronics. Done it many times myself as many professional and DIY restorers have done. Most rodent residue is water soluable and it is the best way to get rid of it
Loopback of RS232 not only needs TX connected to RX but also DSR, DTR and DCD (Data Set Ready, Data Terminal Ready and Data Carrier Detect), these are for hardware handshake. Otherwise the sender will not send anything because it thinks the terminal is not ready or the terminal will not sent anything because it thinks the receiver is not ready or there is no connection. If you don't care about hardware flow control then short all three together (one in output, the other two are input). If not using hardware handshake then most likely you need the Xon/Xoff protocol unless the terminal and the computer are always able to process the data in time, although you most likely want to sent control-S and control-Q anyway to pause and resume the output.
Hardware flow control can also use RTS (Request To Send) and CTS (Clear To Send). So to have the best chance to get loopback on db-25 rs232 you would want to connect 6, 8, and 20 together, 4 to 5, and 2 to 3.
Sorry, foggy memory. Should be RTS (Request to send), CTS (Clear to send) and DCD (Data carrier detect). It has been a while since I last made 3 wire RS232 cables...
@@russellhltn1396True, but it couldn't hurt to properly set the handshaking pins. Having DCD active should also light up the Carrier light on the front panel. Also, that modem switch on the side might just be for turning the audio coupler on an off but it could also flip the data inputs to the coupler or force a fixed baud rate as well. Most audio couplers worked at 75, 110 or 300 baud in the late 70s/early 80s in my experience (ignoring the weird 75/1200 split things that came along later for services like Prestel)
I guess the thing you smell is rat urine, not poop. Just like male cat's urine it is a marker and it is hard to remove it. The only thing I know to remove that smell is vinegar i.e. acetic acid. You should have use just a bit of diluted white vinegar and it would not smell at all.
You needed to clean the "parts" machine anyway, so better get it out of the way right now, then have it sit on a shelf in all that excrement, and discover in some years time that it's no longer usable, and if only you had cleaned it sooner.
70's Colors... You know what... Looking at that color scheme today brings back nostalgia, it was swapped out so quickly in the 80's that we didn't have long enough to really get tired of it... and funny as that sounds... I kind of miss it! Thanks for showing us this wonderful 70's tech in all it's glory. Oh how I miss the 70's I didn't get into programming until 77 or 78, but I've seen this tech around and marveled at it... now I miss it. Except for the Rat poo, YUCK!!! But I bet it has its own particular smell that is pretty awesome too. The smell of history! The Museum in Mountain View, CA... when you walk in and all those old machines are there... it's just whatever it is about those old machines.
@@highpath4776 remember the avocado green appliances... or those counter tops? There are just things in life that you can't un-see LOL... Well, the retro look is now coming back... How interesting!
Still have my ST-225 Couldn't bear to part with it, remembering how much I spent for it back in the 80's. In June of 1972, for the "introductory price" of $3,400 you could buy a brand new car, a good one, like a Camaro or Mustang.
Yep, somewhere I still have the first hard disk I ever bought, about $400 for 60 megabytes in 1986. It was so noisy I put it 15 feet away in a closet. Fortunately Macs and SCSI could handle that distance.
You memtioned looping pins 2 and 3, but you normally need more than pins 2 and 3 connected for testing serial terminals. The terminal needs to know that it is connec5ed to something and that it is OK send data, so.... Basic 25 pin RS-232 loop-back... pin 2 to 3 (TXD to RXD), pin 4 to 5 (RTS to CTS), pin 20 to 6 and 8 (DTR to DSR and DCD). If half-duplex is selected, then you would expect to see each character displayed twice, once from the internal loop-back and once from the external. Also, I assume that the modem switch should be Off to use the external serial connection instead of the acoustic coupler.
Power electronics engineer here specialising in MRO of rail power electronics. You're cleaning the boards exactly how I would, only think I would change would be to add Isopropyl alcohol to sterilise and act as a drying agent.
Some old capacitors wouldn't be happy with much time with isopropyl. Polystyrene capacitors will degrade. I have also had cases of it attacking coax cables. The insulation between the center conductor and the shield seemed to soak up the isopropyl and distort.
I this case it's more of a rinse instead of a soak in the IPA though, right? Just enough to help get rid of any residual water and unwanted microbiome...
I agree, However I wouldn't use a high percentage of alcohol, maybe the strongest you can get from the first aid section at the store.
Do you have anything against cleaning it with an ultrasonic cleaner?
@@christo930 It may be too aggressive.
Little did you know the RS-232 was the number of Rat S**** in the chassis.
Speaking the truth over here!
Sadly the computer doesn't support CAT-5, because it would surely need some to get rid of the rats.
But at least the rats keep hardware bug from creeping up.
lol rat shit 232
i love this 🤣
Your portable ADDS terminal has the same 3 main PCBs and keyboard as the ADDS 580 used in first Warrex CPU4 systems. The one with the side connector is the FE card ( has the RS-232 I/O logic ) the middle card is the screen memory display buffer ( the display buffer has 9 shift-reg IC's, 1-3 for first 8 lines, 4-6 for the second 8 lines and 7-9 the last 8 lines = 24 lines x 80 columns ). The two main issues are the FE card RS-232 I/O chips SN75188 & SN75189 and on the screen buffer card the 9 memory shift-reg. chip house 2 bits each by 80 positions on the display. The normal test for bad shift-reg chip is to type in 1/2 dup. A B D H P (return) in all 24 lines on the display. A B D H P will turn on a single bit on the ASCII code of the up-case only ASCII display. Many times the A B D H P typed will be displayed as with a extra or missing bit so the A B D H P displays the wrong letters.
would the Envoy work on the centurion(or is it beyond 24x80 ability?) ( your other comment notes the probable failure for the chips - try a card swap between terminals first ?) Presumably CRT in the rat one is power supply related and solvable ?
It's not unusual for the RS driver chips to get blown out. All it takes is some kind of surge on the RS-232 line when it's run a long distance.
@@highpath4776 The ADDS Envoy will work with the Centurion system(s). The ADDS Envoy terminal is a re-packing of the ADDS 520 & ADDS-580 that we used at Warrex (Centurion) in the mid 1970s on the CPU4 system.
@@russellhltn1396 Correct the RS-232 lin driver & recv. IC like the SN75188 & SN75189 ( or 14188 & 14189 ) failed often after lightning storms within miles of the computer system. The long RS-232 cable from the computer to the terminal acts like an antenna when lighting is in the area and blowout the RS-232 I/O ICs on the terminal ( and also the Centurion 4-Port MUX card ).
Good luck finding the Static shift register chips. It was the reason ADDS stopped production of several lines (580/880/980/620) Then the regent series was produced followed by viewpoint. The video memory card is sectioned by 3 groups of 8. abdhp is only need once per section not all lines. Check test key -L clear screen abdhp -K K abdhp -K W abdhp . re: ctrl is control key, space is space bar. The space is important. Any bad shift registers will show as a @ sign. FYI -K was direct line access @ line 1, W line 24
Just saw the part of the video showing a large number of ((( ( (( ( in a field of what should be ASCII spaces. I would bet the ((( ( (( ( because the error in the raster display is in the middle grouping of 8 lines the issue is with the ADDS memory shift-reg card's 9 Shit-Reg. ICs, one of the chips is flipping bits because it's just bad, ( This was a very common problem and many time was heat related. ) Space code = 0x20 and the ( code = 0x28 looks like a bad shift-reg bit.
Nicely spotted!
Ken swinging in with the proper expert diagnosis! Gonna have to get you down here to help get this thing and the printer fully up and running one of these days!
To get the keyboard loopback working, you might have to assert DCD to the terminal; on the VT52-like terminals I used, you could loop DTR back to DCD; on those terminals, DTR was an output that would be asserted when the terminal was "online". We would also wire those two to the DSR pin. You may also have to loop back CTS to RTS if the terminal requires a hardware handshake.
"A switch here that says 'modem' underneath it - I have no clue what that does."
Pretty likely it selects between the acoustic coupler and the data port. It's not clear if this was actually set correctly through the serial experimentation. I also suspect the rear BNC is for connecting an adult-sized display. I'm actually surprised more of the protocol controls aren't on the front panel, given it's a luggable terminal for working in the field.
I was silently screaming this at 25:44 when he tried jumpering the pins on the serial port! 😱
Thinking the same thing for the BNC Jack. Otherwise I can't make sense of it. The number of things that video output is not a standard on when it has a built-in display is so annoying.
oh and @iroll you're right I hit the timestamp and immediately went AAAAARrrrrrrrrrrrrrrrrr.
"Modem" position enables the acoustic coupler and built-in 103-type modem (good to 300 baud). The "up" position routes the data path to the RS-232 subD connector and allows you to use the faster baud rates for direct connection to your computer (or a faster modem)
I saw the title and yet I still chose to watch this during breakfast. Thats on me.
Can't say I didn't warn you ;P
The "carrier" light would be for the acoustic coupler. Remember how, in the days of dialup connections, if the connection dropped you'd get a "NO CARRIER" message?
Ah! I totally didn't think about that, but makes perfect sense!
@@UsagiElectric as mentioned in some other comments I have an Otrona Attache portable computer that is about the same overall size as the ADDS terminal but I think the crt is larger and it has two 5.25" floppy drives. But no built-in acoustic coupler/modem. It could even run from battery using a separate power pack thing. I've never seen the power pack. In the early 80s I did some programming for building energy audit software at a place that was selling it to utility companies after a federal mandate required them. They were marketing it with either Compaq Portables or the more compact Otrona. The "base" Otrona ran cp/m on a z80 but most wound up being sold with a PC compatibility card that ran a slightly modified DOS 2.1 on an 8088 or 8086.
All amplitude modulated signals share the use of a modulated carrier wave whose amplitude is, well, modulated.
21:17 I couldn’t grok what you were concerned about 😁 - love all your hardware restorations, these pieces included, don’t worry about it 👍
This has to be the most psychedelic portable terminal I've ever seen (and I've been messing with computers since the late seventies).
Good job using all your available resources. I look forward to the part two.
If you can't hear the high-frequency CRT noise, you can use a phone with a software spectrum analyzer. This should work.
I have seen other people use water to clean PCB's and Motherboards, I totally agree with your cleaning method
24:36 oh that beautiful CRTs Sound. I believe I'm watching in 480P and as soon as the switch is hit that beautiful glorious high frequency noise somehow was not compressed out of the A/V stream.
I love your troubleshooting work! Your forensic skills are remarkable. Love all your videos.
Your picture of the Digital brand computer brought back a memory I had forgotten. In 1995 I got a job selling pc's at Sun tv and electronics, long gone now but think Best Buy. We sold several brands of pc's and one of the better ones was the Digital brand. One day we get in a new shippment and we put 2 out on display. About 2 hours later we look over and the damn speakers were on fire on the first one. We get them unplugged and about that time computer two's speakers are smoking. Took them all down, back in the boxes with the charred speakers! don't know what happened but Digital disappeared from the store!
11:08 I would put them in the dishwasher. I've done this before, but the boards were modern, like a board from a wifi router. Worked good for me.
Hmm, yeah, I was wondering when you'd remember the "parts" machine.
In the immortal words of Homer J. Simpson, "DOH!"
I was thinking the same thing - so the "sudden shift" was more a "finally!" for me.
In the words of the Fresh Prince, "He a little confused, but he got the spirit!"
freeze frame at 3:26, this is the stare your father gives you at the dinner table when you tell the darkest most nauseatingly offensive joke that makes your grandma vomit, your mother choke, and your step brother piss himself laughing all at the same time
On the capacitors you're measuring the raw unregulated DC. this is typically higher and perfectly normal, especially when not under load To be a regulated output in fact it needs to be higher. If you measure the voltage at the actual output that then goes to the electronics you will find your expected normal voltages.
The large capacitors in a linear power supply are most always pre-regulation. So those voltages you got are fine. The 13v regulates down to +5 and the +/-27v regulates down to +/-12v. They will also go down when the supply is loaded but you can see the headroom built into that power supply.
I should also mention that the large capacitor in a line operated switch mode power supply is more or less tied to the AC line. So don't attach any test equipment without using an isolation transformer.
Well, now you have a spare parts machine with an aroma. :) I think you mentioned that you have an ultrasonic cleaner but not a large one, and that could help to really sanitize those parts. Might I suggest setting up some kind of fund-a-large-ultrasonic-cleaner button or page. I would contribute to that.
20:55 I was looking away and the clap sounded like a part going up in smoke Dx
It kinda reminds me of the Commodore SX64 in terms of case design. Cool stuff!
Some put them into dishwashers so your approach is positively gentle in comparison. The output you see is caused by 3802 and 3809, but you'll find that soon enough :)
In the early 1980's I worked at a Chuck-E-Cheese's and we would pull the main boards out of video games and run them through the industrial dishwasher to rid them of spilled soda and "goo". They worked fine after some compressed air + drying time. 👍🙂
Imagine if any of the companies making luggables would have turned theirs on the side, rotating the CRT to sit up high, what a revolution in ergonomics it would have been.
Portable poo-dee-poo-eleven console!
A perfect way to clean is, besides using a mild detergent, distilled water as it is mineral free and thus non conductive. A 100% dry out is to set and oven to its lowest temperature i.e. "warm" (pre check the oven with a thermometer) to fine adjust, leave the door slightly or fully open.
At a temperature of around 125-150F and a small fan blowing air inside, place the cleaned item to be dried inside for a few hours. Any water residuals will have evaporated! Worked wonders for me! Dried out any device including Mobile phones!
Thereafter spraying/soaking all in Water Disbursement Formula 40, widely know as WD40, does wonders!
Wow, I hope you show up at VCF East, but I do understand that is too long of a drive for you, especially toting all that stuff. It was great seeing you there last year.
I found out the answer is "no". The displayers list is full and registration is close. You were not on their list this year.
@@Daveyk021 plenty of other shows and show and tells to be done. Presumably awaiting rest of Centurion build and the Bendix for the computer museum to be put to bed first
I am very much so attending this year! I just won't be displaying anything. Last year was epic fun, but I didn't actually get a chance to see the show. So this year, I wanted to make sure I got a chance to go around and see and talk to the other exhibitors!
@@UsagiElectric And how much will you come back with ( or consign to FedEx ..!) ( remote access to the centurion sorted from the hotel room at all ?)
The sheer 2001: A Space Odyssey vibes coming from that terminal.
I though PO OP was some kind of comms flow control
(28:00 "in half-duplex," keyboard characters should echo locally, is what I think you meant to say.)
Anyone's guesses on whether that Modem-Up-arrow toggle changes polarity for DCE-vs-DTE?
THANK YOU!!! I just looove interesting terminals, and this little guy is just gorgeous to look at!
-and I've never been brave enough to try Simple Green on electronics, thanks so much for your advice on what typically is and is-not safe to use the cleaner on.
Is bridging pins 2 and 3 enough, or should you be connecting RTS / CTS and all that? A proper dummy plug. Maybe connect the terminal to a PC so you've got decent control of the other end.
That coax plug at the back looks like a BNC, and I'd guess it's an external monitor socket. The fact that the top of the terminal is flat also hints at that, that you'd use an external monitor back in the office. You could check if it connects near the video generator internally. It's not like the terminal would be put in a cupboard when you're not travelling, it was expensive! So you'll likely have been using it at the office too, with a proper monitor. Probably just standard composite video.
Really want to see this thing working, keep it up!
Wow! I had no idea that you can clean electronics with a household cleaner and water!
I think you meant "mouse" instead of "rat". That smell is unmistakeable and vile. You did not waste time cleaing up both systems as you may needs parts/cards from both to make a good one. IPA is a good drying /sterilizing agent after simple green as was already suggested. I have a dehumidifier in my basement and crank it up with the boards surrounding it after a good going over with compressed air. Also a good idea to remove any socketed ICs and use compressed air - water gets trapped in those sockets.
This looks like a remote terminal Owen Wilson would use when hes away from the TVA.
It reminds me of the IBM 5110 with the miserable tiny CRT on the left and mysterious buttons on the right.
Heh, I see a number of PCBs! Poop-Covered Boards! I do not apologize.
In a PC, that Seagate is as slow as hell... in a PDP, it'll probably be great... so tough... you can play football with them and they'll still boot.
If you ever do a 'tour' up in Canada, you can borrow my TI Silent 700 as a much lighter weight terminal! Just supply your own 'fax paper'.
Gut it and fit the rest of the computer directly in it and drive the CRT directly.
Would have a fully portable unit.
Get a rattler mink... More on the real side: Feed the DIN 25 w/ signals, incl. the control connectors: CD, RTS, CTS.
Send it logic is always sound. 40% of the time, every time.
Hmm, must be Ænima, but so difficult to choose since they are all great.
This was definitely the wrong video to watch while eating breakfast.
My Mom told me I should never watch anything with poop in the title.
If you're reading voltages at the capacitors, wouldn't that be pre-regulators?
Right out of space 1999
A couple of things here:
1) Be careful with the CRT board and CRT itself. Those run on VERY HIGH VOLTAGE. The CRT Anode and flyback transformer outputs could be in the thousands of volts! Even the grid drive runs in in the 30-200 volt range. You may want to use an isolation transformer when troubleshooting it.
2) The Data / Modem switch might do one of several things. I suspect that it may control whether it operates from the accustic coupler or whether it operates directly from the DB25. It could also control whether the output is full duplex or half duplex. Early terminals did sometimes connect over phone lines to mainframes. Others were directly connected. Likely this reflected whether they ran cable or connected from another office.
3) The Linefeed settings could reflect which type of computer you are connecting it to and whether a return is a carriage return, a line feed, or both. Different computers handled this differently. Again, this might also set which type of terminal interface the mainframe you connected it to used. Different models used different interfaces. Examples of some of the terminals protocols included VT-100, ADM-3A, VT52, D1, D2, D3, Televideo 910 through 9150, VT220, ANSI, and others.
Thankfully, i had dinner about an hour ago. Never seen so much rodent poop inside electronics and i certainly have seen some in my life.
Btw. which brand is your editing monitor? Just curious, because the aspect ratio looks quite unusual to me.
It was definitely rough inside!
The editing monitor is an ASUS VZ239H-W, just a standard 23" 1080p monitor, nothing fancy. Perhaps the 50mm lens I filmed with made it look a little weirdly shaped.
@@UsagiElectric Thanks, it looks very square in the video, almost like an LG DualUP
Just how big is a processor rack for a PDP-11?
which movie is shown at 5:13 ?
It was from the episode "Computer Killer" of the original "Hawaii Five-0." The bad guy uses the Envoy to remotely connect and hack into all sorts of fun stuff!
Can't tell you how many times I've dredged through poop only to realize there was an easier way. Usually had to do with my marriage more than electronics but you know.. You live and you learn. 🥴
is the bnc a 20ma current loop ?
About your method of cleaning the boards: Is there any OTHER way of cleaning electronics quicly and reliably? From what I know, water does no damage whatsoever unless they are operating.
It's not the water doing the damage, but whatever minerals are dissolved in it, which get left behind as a coating that might short stuff out after the actual water evaporates.
Back in the day they would often hose down boards with Freon 113. It works great for cleaning circuit boards. Unfortunately, it's not so good for the ozone layer.
Deionized water is fine for cleaning boards. It won't damage most components and doesn't leave residue behind. Tap water will leave mineral residue that can potentially cause issues.
@@AttilaAsztalos I once cleaned a 70s b&w tv board with water from my well. Had no problems. Must have been lucky I guess
The eventual fate of all ancient computing equipment; disintegrated by rodent feces.
Sure that terminal is gorgeous, but I spent the whole episode drooling over that cute HP multimeter
I could stare at those gorgeous 7-segments all day.
Those desctop meters are amazing I have a 1970s simpson meter that has a nixie tube display.
it looks as if it would spring right into your face when you apply wrong voltage
@@timothydelaval1089you lucky dog. I have a Simpson multimeter that has early LEDs. Pretty rare I believe. Maybe not.
Much better than propping a clamp meter up with a screwdriver!
6:15 Mouse. That's mouse poop. Rat poop is a LOT bigger. About the size of your pinky fingertip. Source: I have pet rats.
Not particularly relevant, but rats and mice behave differently, plus you really can't underestimate the size difference. Rats are absolutely MASSIVE compared to mice.
Domesticated rats actually make really good pets. They're very intelligent and friendly. I had a pet rat a long time ago, and it was amazing how friendly he was. He loved to climb up on my shoulder and eat sunflower seeds lol. He loved to be held and petted too, and one time he even fell asleep in my hand!
Sounds like an expert!
You're totally right, I don't think a rat could have comfortably fit inside of this thing anyways. I've seen a few proper rats in NYC, and you're right, they're massive!
@@ct92404 Mine like to come sleep with me on the couch, and two of my girls like to sleep in the blankets with me. One was an escape artist and would open the cage door at 4am to come find me and crawl into bed with me. They aren't called pocket puppies for no good reason.
The retro computer forum transformed into a zoology class 😅
That thing is more 70's than a Foghat 8-track. Absolutely outstanding. :)
Wow Foghat...I'd forgotten!
👌
Wow, flask back to my college days!
"flash"
RIP Lonesome Dave.
"Slow ride, take it easy!"
The PooDeePee 11 Terminal
I'm not sure DEC would be happy with our new naming scheme, lol.
Right now there is most likely a family of rats on the phone to the police reporting a stolen toilet.
Might think about getting an ultrasound cleaner. No complaints on your well reasoned cleaning method though. I imagine that thing when it heats up is going to "share the joy" for a while till it burns off completely 😅
Yep - Ultrasonic cleaning would do a lot. A lot of people, myself included, use it a lot to clean up contaminated (battery leak, fluid spill) and/or corroded circuit boards. Keep in mind that older electronic parts can be dried out and cracked over time, so that can be a problem. They should be replaced anyway, but thorough inspection and checking is always needed.
Usagi !!! Where Electronics, Software, and the Black Plague all meet...
You never know what you'll get on the Usagi Electric channel. Vacuum Tube computers? Insanely loud printers? The Last of Us? Everything is on the table!
When I worked for Tektronix we washed 99% of stuff coming in for repair. Then it spent a couple (or more) of days in a drying oven. sorted a lot of problems out and made many look like new. standard procedure.
Heard about that, it probably really is the best way to clean this stuff.
To add one nugget to the cleaning bit- It's a good idea to be careful with wire harnesses in addition. Water can wick several feet inside the wire insulation and can stay there. This can cause issues in the long-term on some wire types. It might also be a good idea to hose the boards off with distilled or de-ionized water as a final wash so that it doesn't deposit minerals on the boards during drying.
hope you checked the voltages on the second machine? that picture came up suspiciously fast, if its getting too many volts it'd cause that, check crt heater volts , these sort of tubes are usually 10 to 11 v
Usagi's Logic, a derivative of "If it jams force it, if it breaks it needed replacing anyway."
I like when he does that. My take for a long time has been, "it's already broken, whats the worst that will happen? It will be broken when i'm done?". Funny enough, things get fixed faster that way because you don't waste time thinking about something 2x longer than you need to because of fear of breaking it.
I doubt he would do that if he seriously expected anything to explode.
Sometimes, you just gotta send it!
It's just Schrödingers cat. Until you try, it's both dead and alive, and only trying it out will show you which is true.
@@2009dudeman That's my personal tech-support guarantee. "It won't be any *more* broken after I have a go at it!"
"I've spent the last day and a half swimming in rat excrement and I didn't need to"
Brave guy did it anyway, what a champ
The rat machine might not be permanently out of the picture. Would it be possible to sub the CRT module from the clean machine into the rat machine? If only to give the rat machine a second chance to show something? In order to better deodorize the rat machine parts, perhaps a dunk of each board for a few hours in some Nature's Miracle or equivalent enzyme/bacterial product from a pet store might be helpful. An emanation of especially pungent ammonia odor is good news here, for it means the waste is breaking down, releasing its nitrogen. (Sometimes a situation has to stink worse before it ceases stinking.)
"We do these things not because they are easy, but because I'm a little dumb." - John F Usagi.
Ah, a day in the life for shango066, too.
I love Simple Green. No angry keyboard tapping here. I love watching your restoration videos. I live the dream through your channel.
Thank you so much!
Didn't feel like too drastic a shift of gears to us -- with the goal of getting a nice portable terminal, it's all part of the same project, and we can enjoy the process of discovery/realization right along with you! I have a feeling the "smelly" machine will prove more useful in future diagnostic efforts now that it is clean as well.
Yeah, I don't see cleaning the now-parts-machine as a 'shift in gears'. You rather expect twists and turns with projects like these, all the while holding out hope that the 'parts machine' may get a fresh keyboard one day too :)
25:46 the Modem switch is down so I'd expect the system is looking for data from the acoustic coupler. I can't make out the switch in later clips.
I restore pinball machines and also have a lot of nasty boards and electromechanical parts to clean up. I suggest getting yourself a 10-22L ultrasonic cleaner (they're surprisingly inexpensive) for future projects. A 50/50 mix of Mean Green and water does great. Next, a quick rinse under the tap and then the air compressor to blow out any water. Lastly: this works great for coils and transformers too! After their bath, they sit in a tupperware container full of silica gel beads for a few days. Overall, it's much gentler than using a brush, and the ultrasonic gets to every last nook and cranny. I've had many crusty barn find come out of the cleaner looking like it rolled off the assembly line.
those big caps are almost certainly on the unregulated part of the psu section .
Of course they are. And it scares me that that wasn't obvious to him...
You can absolutely wash electronics. I've seen Tektronix and Fluke service manuals, where they discuss how to clean boards with water and detergent. Some Tek scopes have water sensitive components and they are labelled as such with the instruction of removing them before hosing down the device. SO you are 100% right with wahsing the grossness off.
PCB assembly houses often will use what is essentially a dishwasher, just with no boil cycle, and drip dry, and regular dishwashing powder, to clean new boards after assembly. Big volumes they have a big machine, but small runs just a regular dishwasher is often used.
Why does water kill phones then? IDGI
@@seth8629 Because the phone has a charged battery in it. Take the battery out, and remove water sensitive components (speaker, things that use water soluble glue, etc.) and it can be hosed down. The damage comes from having electricity pass through contaminated water, causing electrolysis and rapid corrosion. No electricity, no electrolysis or rapid corrosion even when using contaminated water that is conductive.
In college as an experiment we tried submersion cooling computers to see the effects it had on cooling efficiency. Essentially to see if it could be more cost efficient and environmentally friendly to passively liquid cool computers, instead of using fans or pumps to air/liquid cool them. Turns out, no, the best form of cooling is actually just an air cooler on a big a** radiator. Guess we came to the same conclusion people did a long time ago. But, for our experiment we essentially just took a big plastic storage tub, filled it with various liquids (we used distilled water, vegetable oil, motor oil (used it in our cars afterwards), mineral oil, we even tried a couple types of alcohols courtesy of the chemical engineering department (cleaning or solvent based, not the drinking kind). Distilled water didn't cause an issue as long as we rinsed and dried the boards first, we actually tested the water throughout the test to make sure it was free of contaminates that would make it conductive so we didn't damage the boards.
The only things that actually damaged the boards was the solvents, they must have eaten away at several components on the board, and we expected this. Water and the various oils however caused no damage to the board.
I worked in a TV repair shop for a while. They taught me to always wash the high voltage transformer when replacing the usual parts. We used a water with a dish washing soap. Then it was dried with a blow dryer and that was it. Why shouldn't it work? It had to. However, I recovered some phones that were sleeping with fish for a while (battery on). I think the tons of rust and electrolysis products were harder to clean up than just some rat poo. It was really, really surprising the phones started to work. I was almost confident that you can just wash electronics and it would work. But well, there was that one lousy rubber dome keyboard. After washing and drying it became absolutely dead.
@@seth8629 Partially because the phone has a live battery with a charge in it, while the disconnected circuit boards do not, and were given a proper drying before power was applied. Water and powered circuitry do not mix because it causes electrical shorts, since the water is conductive.
People that complain about washing boards have never worked in PCBA manufacturing. We run assembled boards through plain water washes every single time, it's how they are cleaned before configuration and testing. Heck, I literally spent over an hour washing boards just a couple days ago at work. Although, personally, if the board can handle it, I just bake them. Not only does it dry them out more thoroughly, if I do have to do any touch up soldering it makes that go so much better as well.
I doubt you use tap water though. So much (natural) contaminants in that I wouldn't buy from you. But for this videos purpose it was fine.
@@bzuidgeest It's literally just Deionized water, a.k.a. purified water. And we manufacture for some of the biggest companies, including stuff in your computer, so you kinda already do. Also, if you travel by plane then I hope you don't mind :)
All the Warrex / Centurion minicomputer PCBs had the solder flex remove during mfg by a trip to the Sears dishwasher for a wash cycle (without any heat dry cycle). The PCB air dry in a rack for two day the moved to a heated burn-in rack with all DC voltages ( +5, +12,-12 ) for 48 hours for being tech-ed and installed in to a Centurion system. We even ran field repair returns in the Sears dishwashers as needed. Yes the Sears dishwasher was purchased at the local Sears store in the mall.
Came here to say it , but you beat me to it. People who object to washing PCBs have never worked in a large-scale manufacturing environment.
@@kenromaine2387 I have used my dishwasher so often over the years for PCBAs. Sometimes it's just easier than cleaning them by hand.
12:57 Transformers, coils.... Don't forget non sealed relays. I've seen plenty of boards that make a "splop" noise and fail to work over the years as the relays have solvent or cleaner in them :-) I enjoyed your show and tell "shit show"
Maybe you could try the terminal with the Centurion? Or a modern laptop. Just to see what problems are specific to the terminal and not to the PDP.
The print ad mentions a price of only $3400!! Today's inflated equivalent: about $25,000!!!!! You could buy a nice car for $3400 in 1972. Today $25,000, not so much.
lot more technology in cars now, you seem to be paying for heated seats, airbags, most systems are injection turbo with aircon and so on
Agree a nice car for $3K and a 1,400 sq ft house with 3 bedroom, 2 baths & 2 car garage for $25K in Dallas with a years pay still in your pocket in 1975. My starting hourly pay at Warrex / Centurion was about $4 per hour in 1975.
@@kenromaine2387 10k per annum Mortgage on one income at 2.5x annual income
Please take care with that rat poo and pee - there could be a risk of Weil’s disease - mask-up as well as gloves!
Excellent series. I haven't seen an Adds Envoy in decades. They were nearly a decade old and being sold for nearly scrap prices in the early 1980's when we were still using one. It was a much better solution than other portable terminal we had, a the TI Silent 700, for portable work in the field. I can't wait to see your whole portable built out. WOW!
Silent 700 with magnetic bubble memory was an absolute BEAST. I went through a lot of thermal paper.
That terminal is so friggen cool
Hoping to bring it with me to VCF East this year, if I can get it going in time that is!
@@UsagiElectricsweeeeet
I was just wondering if you were connecting the meter correctly on the capacitors, my theory is that you may have had the negative meter wire on the minus 12, that would have given plus 17 and plus 24 on load.
12:12 - Anyone complaining about washing the boards is probably not aware of the fact that to ruin electronics with water, they have to have power flowing through them. I knew this at 13, and I bet my friend $20 (that's like $40 now) that I bet this 286 motherboard that I got from school (legally - no case or anything, just the board) will survive a plunge in the bath. I showed it to him POSTing using my 386's video card and keyboard to go into the BIOS and do stuff. Then I took all of it apart, and proceeded to dunk it in a bathtub with 2-3 inches of water in it. 20 mins later I took it out, and I said to my friend to come back in a couple days. I immediately removed all the chips (this was an old sucker, lots of discrete chips) including the CPU and dried those separately. I put it all back together, got my buddy to come by, and (I tested it previously lol) it POSTed and the keyboard worked, onboard RAM (like, 10 DIP modules), everything was fine.
Bollocks to the commenters who think this is a bad idea. I've since put motherboards in dishwashers to get grime off them. Just let it dry.
I had 10 units like that terminal in working order, you could have had. I donated them to my College for display cabinets with antique dumb terminals in the computer lab building that have never been plugged in? I do have a KTel 5” drive suitcase computer where the cover is the keyboard with a 6” diagonal green screen 📺
“Not tiny, but also not huge.” That I have heard before 😊.
You shouldve been in a VC with him, he once did a Penis joke with the Long Teletype Carriage for the Bendix
What a gorgeous 70's-tastic beast, inverted screen too. One thing I noticed through all the comms testing was that you had the 'modem' switch down, hinting that the acoustic coupler was the device of choice. Is there a chance that disables the RS232 port?
Water and a non-acidic/non-alkaline cleaning solution is actually used professionally for cleaning, so anyone who did do the angry keyboard thing needs to research. You'd let it dry and then do a bath with Isopropyl to just make sure all the water was expelled, but air drying is also a legitimate drying method for PCB's and electronics. Done it many times myself as many professional and DIY restorers have done. Most rodent residue is water soluable and it is the best way to get rid of it
Loopback of RS232 not only needs TX connected to RX but also DSR, DTR and DCD (Data Set Ready, Data Terminal Ready and Data Carrier Detect), these are for hardware handshake. Otherwise the sender will not send anything because it thinks the terminal is not ready or the terminal will not sent anything because it thinks the receiver is not ready or there is no connection.
If you don't care about hardware flow control then short all three together (one in output, the other two are input). If not using hardware handshake then most likely you need the Xon/Xoff protocol unless the terminal and the computer are always able to process the data in time, although you most likely want to sent control-S and control-Q anyway to pause and resume the output.
Hardware flow control can also use RTS (Request To Send) and CTS (Clear To Send). So to have the best chance to get loopback on db-25 rs232 you would want to connect 6, 8, and 20 together, 4 to 5, and 2 to 3.
Depends on the terminal. A lot of them only need 2,3 & 7. They might have a "bias" to keep the other pins happy if nothing is connected to them.
Sorry, foggy memory. Should be RTS (Request to send), CTS (Clear to send) and DCD (Data carrier detect). It has been a while since I last made 3 wire RS232 cables...
@@russellhltn1396True, but it couldn't hurt to properly set the handshaking pins. Having DCD active should also light up the Carrier light on the front panel.
Also, that modem switch on the side might just be for turning the audio coupler on an off but it could also flip the data inputs to the coupler or force a fixed baud rate as well. Most audio couplers worked at 75, 110 or 300 baud in the late 70s/early 80s in my experience (ignoring the weird 75/1200 split things that came along later for services like Prestel)
I guess the thing you smell is rat urine, not poop. Just like male cat's urine it is a marker and it is hard to remove it. The only thing I know to remove that smell is vinegar i.e. acetic acid. You should have use just a bit of diluted white vinegar and it would not smell at all.
Would you have still cleaned and restored the poop machine? Otherwise I'm glad you didn't look at the parts machine first.
Covered in poop, as in *0xDEADBEEF* ?
(A bit of obscure programmers´ humor there.)
Probably more like 0x0DDFECE5
You needed to clean the "parts" machine anyway, so better get it out of the way right now, then have it sit on a shelf in all that excrement, and discover in some years time that it's no longer usable, and if only you had cleaned it sooner.
70's Colors... You know what... Looking at that color scheme today brings back nostalgia, it was swapped out so quickly in the 80's that we didn't have long enough to really get tired of it... and funny as that sounds... I kind of miss it! Thanks for showing us this wonderful 70's tech in all it's glory. Oh how I miss the 70's I didn't get into programming until 77 or 78, but I've seen this tech around and marveled at it... now I miss it. Except for the Rat poo, YUCK!!! But I bet it has its own particular smell that is pretty awesome too. The smell of history! The Museum in Mountain View, CA... when you walk in and all those old machines are there... it's just whatever it is about those old machines.
I had kitchen in orange, sofa and chairs in orange black and brown and diff pattern same for wallpaper
@@highpath4776 remember the avocado green appliances... or those counter tops? There are just things in life that you can't un-see LOL... Well, the retro look is now coming back... How interesting!
Wow I thought your title was just clickbait but the poop is real.
poo
The poop was always real. You just had to believe in yourself.
portable dreamsicle terminal
with a side of hantavirus
Ohh that ADDS terminal is GORGEOUS
It really is stunning!
Still have my ST-225 Couldn't bear to part with it, remembering how much I spent for it back in the 80's.
In June of 1972, for the "introductory price" of $3,400 you could buy a brand new car, a good one, like a Camaro or Mustang.
Yep, somewhere I still have the first hard disk I ever bought, about $400 for 60 megabytes in 1986. It was so noisy I put it 15 feet away in a closet. Fortunately Macs and SCSI could handle that distance.
How come noone in the comments noticed the Tool reference in the chapter title at 21:14?
You memtioned looping pins 2 and 3, but you normally need more than pins 2 and 3 connected for testing serial terminals. The terminal needs to know that it is connec5ed to something and that it is OK send data, so.... Basic 25 pin RS-232 loop-back... pin 2 to 3 (TXD to RXD), pin 4 to 5 (RTS to CTS), pin 20 to 6 and 8 (DTR to DSR and DCD). If half-duplex is selected, then you would expect to see each character displayed twice, once from the internal loop-back and once from the external. Also, I assume that the modem switch should be Off to use the external serial connection instead of the acoustic coupler.
This.
Gorgeous! What was the movie/TV show that you showed it in?