Relay Computer ep. 2 - Building the 16-bit adder (part 1)

[@keanuciupka2074]

This is already one of the coolest video series, in terms of pure content at least, however the loudness difference is really killing it for me! I measured the volume of the speech (imo. mandatory to understanding) versus the volume of the music, and the music by itself is at least twice as loud as the narration in any part... Dude, I can't listen to this over my stereo, because I can't spin the volume knob fast enougth, to keep a functional balance between understanding the circuit and not getting swatted for disturbance of peace, so please: Fix your loudness in video production , so we can understand you!

[@RetroSwim]

I don't know what EDM package that is, but a Design Rule Check would have picked up your intersecting traces. Always always always do a DRC before having your boards fabbed!! Always!!!

[@ClicketyClack]

Yep, I sure learned my lesson on that one. I'm still very much a beginner when it comes to PCB design.

[@gorillaau]

Clickety Clack Good think it wasn't a multilayer board with the shorted track on one of the middle tracks. :-p

[@tinsmakinglab7420]

I recommend EasyEDA for doing that stuff

[@mati_ko]

I love those clicky relay sounds

[@shelydued]

As a college student desiring to be an electrical engineer, electro-mechanical devices such as this amaze me! I would love to build one some time, and possibly go as far as adding some sort of paper tape feed and do more complicated functions. Keep up the great work! ~Sheldon Leigh KG7DTC

[@ClicketyClack]

Thanks, I will!

[@gorillaau]

Clickety Clack Say have you had a look at core memory? Not sure what's really involved in this technology.

[@After_Tech_Industries]

Thank you for 4:11 & thumbnail, I am making a digital copy of this for you, out of pure hope this project can continue!

[@After_Tech_Industries]

the thumbnail is from ep:1

[@sprybug]

Mmmm, love the sound of relay clicks.

[@TheDdm1234]

Reminds me of university days, we did this in logic works, but doing it for real would be lovely

[@Transled]

This is a great video. Thank you so much for the series

[@StasisTV]

the noise relays make is so cool

[@haakonpad]

This is brilliant! Great videos dude, keep it up. Relay computers are so satisfying to me, the way they click clack away makes me feel all warm and fuzzy inside.

[@ProtoG42]

Great video!

[@VoidHalo]

I was gonna blast you for the music thing, but you already acknowledged it so no point in beating a dead horse. This is a great video, but I would have preferred if you left the Arduino out of it for the sake of purity. Otherwise I thought it was great and even a little inspirational. It would have been nice to get some sort of specifics on the power source(s) used and how that end of it works. Some sort of diagram online would be useful as well, particularly for the way you wired it to the Arduino. I'm still relatively new to electronics and would one day like to make something like this. I've played lots with logic stuff, but I'm still new to the actual hardware side of things. Love the way the relays click. Looking forward to seeing more in the series. Cheers.

[@absurdengineering]

Arduino is there as a tester. Sure one could make testers out of relays, but it’d be more work. Once such a computer is made, it can be used as a tester in place of the Arduino.

[@VoidHalo]

@@absurdengineering Yeah, like I can totally understand a project like this using semiconductors for memory since it would be wildly impractical to make any significant number of bits with discrete hardware. So I understand there are SOME limitations to what making something purely out of discrete hardware would be. Especially if it's something that really has nothing to do with the actual function like a tester, as you said. Still, imagine how satisfying the clicking would be from a 8Kb memory module made entirely out of relays. mmmm. Also, one has to wonder how much space a thing like that would take up. Just doing back of the envelope math, the relays I have fit very snugly on a bread board with a standard pitch, and take up an area of 1x2cm. That'd take at least 16,000^cm of board space. Nevermind the fact that your boards are probably gonna be no larger than 30x30cm. So you'd have to stack them or something. And hell if I'm gonna figure out how many 1x2 relays can fit on a 30x30 board and how many of those boards you'd need for 8,000 or 16,000 relays, or however many you would need.

[@txd]

Great video. Cant wait for the next one :D

[@gordonlawrence3537]

Your "short gate" used to be known as a "wired or" way back in the 60's. One question though - where did you get that many decent quality relays without it costing an absolute fortune? Relays for crappy ones over here run to about $2 and if you want Omron or someone else good it's more like $4.

[@harrymu148]

only place to get them is to to scouring aliexpress or smth like that...

[@PavelDytrych]

Awesome :-)! Thank you for this very instructive video.

[@derekchristenson5711]

Cool! I'm very interested to see where you go with this. 🙂

[@swrdghcnqstdr]

Damn, these videos are good.

[@josedominguez2021]

HIPER nice vdo man.... Exelent. Thanks. I love Relays.

[@marcoprada-rizzo7886]

Thanks for your support. Could you please tell me what PBC Software did you use to build it?

[@Enigma758]

One problem with relays is their cost!

[@absurdengineering]

On eBay there are relay lots of 500-1000 pieces that go for $0.50/relay, it’s a matter of patience though. Many of those are SMT but that’s progress for you: those relays are also quieter, which often goes against the design goals :)

[@DSUSN127]

Cool video. Really interesting.

[@edgeeffect]

These are excellent quality videos... it's nice to see Electronics people coming up to the same standards as This Old Tony and Clickspring.

[@stuckinastairwell]

Really like this series. Well put together! However I think the music is a bit loud in between you talking. Maybe settle the peak volume of the music slightly bellow you're speaking volume to have the average volume more even?

[@ClicketyClack]

Thanks! You're right about the music - still learning how to edit well for KZbin. I'll keep a closer eye on the levels.

[@pauloconnor2980]

I assume that D1 & D2 are clamping diodes for the relay coils?

[@After_Tech_Industries]

0:18 what is that yellow piece?

[@ClicketyClack]

It's a resistor network. It contains a bunch of resistors in a single package with a common ground pin. Here it's being used for current limiting on the LEDs.

[@After_Tech_Industries]

@@ClicketyClack thanks!

[@stickworldanimated9545]

That is so cool

[@tomlocke4270]

Great videos! I just built a full adder on a bread board to make sure I know how it works. Since you already have PCBs designed for the logic gates, do you have extras to sell ? I'd like to work up to the 16 bit full adder, but am new at this and getting my own PCBs designed seems daunting.

[@guidosarducci209]

Oh, do I recognize that pattern at around 11:30! Unmistakable binary counting.

[@dougaltolan3017]

Speed of light carry full adder can be built with 2 3 pole c/o relays.

[@user-yr7m2]

3:11 where does the carry in come from?

[@xakepp35]

Okay, here go overclockers. Hey! Bring me here that liquid nitrogen!!))))) Have you tried to overclock it? What is its maximum switching frequency, at which test is passed consistently without error?

[@VoidHalo]

The problem with overclocking is it has actual moving parts which will wear out faster the more time they're used. A mechanical part's lifespan is dictated by how many times it's used, so, say a relay's good for 1,000,000 switches. It's not gonna matter if those are over the course of years or one right after the other. Each time it's switched, microscopic damage is done to the moving mechanisms which eventually adds up to catastrophic part failure. Even regular mechanical switches are only rated for 10,000 cycles for the tactile switches I use. One thing that caught me off guard is even potentiometers are subject to such limitations. Say, 10,000 "wipes" across a given area before enough carbon's been wiped off that it's no longer conductive. This is important because regular trim pots are usually only rated for a few hundred cycles because they're not expected to be used a great deal. Where a larger pot meant for something like a volume or gain control on an amplifier might be rated for 10,000 cycles. It really took me for a loop when I found that out. Now mind you when I say "rated for 500 cycles" that doesn't mean the part's gonna fail after exactly 500 times. But rather somewhere around 500 times.

[@cellularmitosis2]

Excellent videos! Could you boost the volume of your voice a bit?

[@masterlaughter4924]

Damn this is intresting

[@pedroPfxr]

The short gate should be avoided or should have diodes in order to prevent short circuits...

[@Julietmindset]

I don't believe that's necessary for relays, since the output of a relay which is outputting zero is physically disconnected, it isn't a sink. For logic types which require a 0-output to be a sink, then it would be a problem.

[@jacobgilman8189]

Hey, I've been searching for a manufacturer of clear relays in the US, but they all seem to be in China. Just wondering where you're getting supplied from? Either way, good work on the videos so far (they're really high quality), and I'm looking forward to seeing you build the rest of the computer.

[@absurdengineering]

The actual manufacturers will almost always be overseas. Not very many electronic components are still made in the US at all. But you won’t be buying anything directly from the manufacturer normally - you’ll go through a distributor or at least a manufacturer’s sales representative. And those are all in the US. But for products like these if you don’t have thousands of dollars to spend, you’d be getting the relays from eBay anyway, and there you’d be looking for large lots of brand name parts, ideally in their factory packaging.

[@Mckooldude]

This inspired me to make a DPDT relay full adder on a protoboard. My next goal is to figure out easy eda or something to get pcb's made.

[@ClicketyClack]

Awesome!

[@Mckooldude]

The proof of concept build is only a single bit, but my idea to to stack 4 via standoff screws, and then have a fifth board on top with the leds/switched/power in.

[@iceowl]

please equalise the volume difference between your speaking and music tracks.. it's really hard to listen to this.

[@ProtoG42]

Where did you buy the hls-4F3L-DC5V-c’s? I can’t seem to find them in stock anywhere.

[@absurdengineering]

Many such relays are discontinued. The best source typically is eBay, search for “relay lot”, sort highest price first (that’s important), then go down the list and look for good deals. At the moment, $0.5-$0.6 per relay is the cheapest you’ll find DPDT relays. It’s normally hard to copy relay computer projects verbatim because unless you’re willing to pay lots of money for relays with same footprint from an electronic part distributor like DigiKey, your only option is to buy large lots from eBay and adapt your project to the parts you have.

[@tedtate57]

Would have been nice and pleasant if the background music wasn't blowing up my eardrums. Had to keep turning it down.

[@artbess]

Did you made the PCBs on yourself? Because I'm very curoius about the white silkscreen onto the green lamination. Or did you just ordered the PCB from your Layout? Thanks!

[@ClicketyClack]

I ordered them.

[@THEfromkentucky]

This is fascinating.

[@markgreco1962]

Will you release the pcb files

[@laufaaij4023]

5:45 sort of sounds like muisic

[@EDToasty]

I'm just wondering, how come we don't have to pull the outputs low?

[@absurdengineering]

That’s because the relay coils only operate when supplied with current. When the high logic state turns to the high impedance “off” state at the coil input, the coil will turns off - no need for zero Volts to be forced into it. In fact, relays turn off 2-5x faster if their coils are allowed to go to a higher voltage than 0V right after they were turned on. The anti-kickback diodes that are typical on relays aren’t that great: instead an RC snubber or back-to-back Zener diodes are better at preserving the speed of the relay.

[@dzv8799]

cool man!

[@mentaldemise]

Where do you get all the relays?

[@slap_my_hand]

Is there a reason why you are using these huge relays? There are much smaller ones.

[@TomStorey96]

StarTrek123456 my guess is price. smaller things also tend to be more expensive. that or he had an existing stock to use.

[@gorillaau]

Tom Storey Bigger relays have a satifiying contact clack to them. Oh and why not have the contacts visible through the casing.

[@swrdghcnqstdr]

Wouldn’t the first bit adder only need to be a half adder?

[@ClicketyClack]

You can do it that way, but making it a full adder allows you to carry in a bit from a previous operation, so you can add numbers of any length.

[@swrdghcnqstdr]

Clickety Clack Aha! that makes sense. thanks!

[@allmycircuits8850]

Also adding 1 to least-significant bit is useful when doing subtraction :)

[@TheJeb52]

we can barely hear your voice, then when we turn it up to hear you, you play really loud music, FIX YOUR AUDIO

[@After_Tech_Industries]

he turns it down but i do agree the music is a tad loud

[@lanchanoinguyen2914]

why you use relay while we already have logic gates by transistor?

[@ClicketyClack]

Because relays are fun.

[@johnwilson3918]

Why use transistor logic gates when you've already got a computer, lânchánđời? I guess you would be even less impressed with a fully mechanical adder kzbin.info/www/bejne/qJW3YoyKbqaChqM These videos give you a true sense of the history of building computers in the 20th century! Clickety Clack, you've inspired me to use an Arduino to test my 8-bit adder - (using crummy CMOS logic). An Arduino, SIPO and PISO shift registers should do the trick! Brilliant video! Thank you!

[@lanchanoinguyen2914]

John Wilson because i still want to make a fast computer myself without noisy and slowly relay.

[@VoidHalo]

You clearly missed the point of this video. Why do you even bother watching these if you can't even appreciate them for what they are? If you want to make a fast computer, get off your ass and go to school.

[@oscarandersson2190]

I built a 16 bit adder in minecraft

[@patvdleer]

Can you explain the rest of what's on the board like the z-diodes?

[@ClicketyClack]

The diodes are just ordinary rectifier diodes (1N4004) which are used to dissipate voltage spikes from the relay coils when they turn off. (Google flyback diodes for a better explanation.) They're not strictly necessary in a pure relay machine, but since I interface this stuff with sensitive electronics (like the arduino) the flyback spikes can kill it.

[@rotorcraft68]

Clever!!!

[@donwald3436]

short gate = input will cry

[@NekomimiNinja]

Nicely explained, great video, but please normalise the music volume to the level of the voiceover.

[@edgeeffect]

Would have been so cool if back when they first made these relay based computers, if they could just like it up to a fast silicon computer to test it. ;) ;)

[@jguy584]

When in the next video coming?

[@ClicketyClack]

Working on it - hopefully this weekend!

[@electromechsolution6699]

I want2 make realy own card

[@arachnid83]

Why would anyone dislike this?

[@ClicketyClack]

I guess some people just really like transistors.

[@gorillaau]

It's not prototyping unless you use a bodge wire. It was an easy mistake to make.

[@teknowlogychannel370]

see this video also; kzbin.info/www/bejne/pIbPq5tshLiHidE

[@TomStorey96]

Nice video but the volume changes are a bit annoying.

[@mans4104]

Next time you can cut the traces with an utility knife, Dremel is great but not for all applications. 👍

[@masterikebana6482]

Это охуенноо!!!))) Thanks

[@blaxrviolent7280]

Sound goes UP and DOWN and UP and DOWN, VERY ANNOYING !

[@waynesmith6417]

Its called a "wire or".

[@micahnightwolf]

I know you were trying to avoid spending extra money on a new PCB but that layout error and subsequent bodged jumper wire is making me and probably other EEVBlog fanboys cringe lol.

[@ClicketyClack]

As an EEVBlog fanboy myself, I agree! :) I may do new PCBs at some point, but for now I'll just have to live with my shame. I think I did OK for my first real PCB design, though. :)

[@powder-phun949]

It's a prototype, and that's how prototypes look. Don't worry about it.

[@dowekeller]

I've seen many commercial products with patch wires snaking from trace to trace, if it doesn't cause harm, and it saves a penny here or there, then why not.