Relay Computer - Sequencer
ฝัง
- เผยแพร่เมื่อ 13 ก.ค. 2024
- The sequencer was a fun build! Although I was able to leverage a true and tested design, it needed many more relays, and finding room for everything on the card posed a very interesting challenge.
Ping me on Discord: discordapp.com/users/39099887...
Music:
Broken Drum Machine - Godmode
Kreuzberg Nights - Futuremono
Drifting at 432 Hz - Unicorn Heads
Thank you for watching, and as always I welcome any feedback or ideas for future projects!
Chapters:
0:00 Intro and Recap
0:28 Why do we need a sequencer?
2:00 Leveraging Dr. Porter's Sequencer Design
3:26 PCB Design and Ordering
5:16 Arrival
6:44 The Build
8:29 First manual testing
9:29 What good is a Pulse Generator?
11:56 Next test with relay clock and "Microcode"
14:03 Automated Testing w/Turbo Mode
16:06 Outro, Thank You!, and ASMR Moment - วิทยาศาสตร์และเทคโนโลยี
I can't wait to hear what the completed computer sounds like.
my guess is a particular flight control system of a particular "commercial towing vehicle" from 1979, Nostromo. When you don't need it to be fast, you need it to work and be fixable with crude tools in flight. B)
@@Zarcondeegrissom Oh yeah, the clacky computer from Alien is iconic.
Al@@Zarcondeegrissom Alien is one of my all time favs for movies. That initial "mother" scene that sounds like a relay computer? Maybe that started it all for me....
@@CameronJamesH It is....relays in space!
My father was a signal engineer for the railroad. Railroads use control logic built in relays. Newer systems have gone electronic for some of the higher level functions, but the low level “track safety” stuff is still in relays, because with relays you can predict what will happen if one fails. ( not so much with discrete logic ). He often had large blueprints from work spread out on tables at the house.
I went with him to the field several times, and have fond memories of sitting in one of the remote relay cabinets when a train went by, with my father narrating. First you would hear the approach relays toggle, then like a wave the clicks and clacks rolled through the case as various circuits triggered. The final clicks were the switch lockout dropping, indicating that it was safe to throw a switch to change the path a train would take.
Just hearing your device go through its motion, triggers that very nostalgic memory.
That is a truly awesome story :) I'm finding more and more about how much relay are used in everything and didn't realize it.
Wow! Not only was it interesting, but also the way you address your ideas and share design hints is sooo relaxing. Enjoyed all the parts so far and looking forward for the next ones!
Thank you! Very kind, and hoping to continue with the next ones!
Juts discovered this channel and wanted to say how much I love these videos.
One of my favorite 'Ah ha!' moments is when I finally understood what op codes actually did, and how they're just the control lines for all the units. That finished the code > electrons path for me.
For me as well.- this was a learning experience for me. Watching some Ben Eater videoa really helped me with this concept.
@@dipdoting Ben's the one who cracked the egg for me too! It was towards the end of his 8bit computer build.
Love the videos, can't wait for the next part! Your voice is very relaxing to listen to, and all the details you explain really make me want to build my own relay computer!
Im a begginer in making electronics. I find these videos not only interesting but also super facinating. Thank you!
I meant to put motivating instead of facinating 😂 language isnt my strong suit
Thank you! I'm a bit of a beginner myself, I started with relays to get the basics down and understand more about diodes, resistors, capacitors along the way. Keep at it!
Thanks for making these videos. I've really enjoyed them so far. Im currently about 96% done on a replica of the 11 bot relay calculator Usargi did a few years ago.
I've had three people independently recommending your videos, so here I am.
I must resist the temptation to build a copy of your machine!
Thank you, glad to hear about your relay calculator project! Once it's done, you may want to expand on it and it will become your own relay computer!
@@dipdoting haha- I'll think about it. I've done mine by hand on strip board. Possibly a mistake, but each of the five main boards are unique. Being a one bit serial design it does make the alu pretty simple- if slower.
one quick note on the diodes across the relay coils. I suggest replacing them with TVS diodes- regular reverse diodes will slow the release of the coils down greatly. this is because the diode slows the collapse of the magnetic field down as it shunts it. the TVS diodes (or a zener in series with a regular diode) will allow the voltage to rise higher than .6V and speeds the collapse up and thus release of the coil. I am making a relay based calculator and used bilateral TVS diodes on the coils for this purpose.
Don't forget to keep in mind the reason you use flyback freewheel diodes to begin with. To clamp the voltage. Raising that threshold might cause problems if it ends up higher than what your parts downstream can take. Research your other parts first!
There's some great feedback on diodes, I'm thinking that since I'm building many of the same cards (ie: registers) I can try to use different types just to compare the results. In a machine that's measured in Hz vs GHz it shouldn't impact the performance materially --- will give TVS a try, thanks!
@@AnnaVannieuwenhuyse It raises a good question: I wonder if Konrad Zuse's Z3 machine suffered from any flyback issues. Those relays were massive, but maybe more sturdy and could handle it.
@@dipdoting the relays themselves are not harmed by the flyback voltage spike. It could be argued that the reverse polarity spike actually prolongs the life of the contacts by reversing the magnetic field's potential.
The biggest concern comes from the high voltage spikes hurting semiconductor devices like transistors, which are commonly used for switching the relay coils with small signals. EMI (radiated electromagnetic waves of electrical noise, which causes interference) is also a concern, mostly for industry use and product designers.
@@dipdoting Probably 2x your coil voltage is a good place to try. I finished up a prototype 3 digit adder (decimal) this week made with relays and I got it to run at 200Hz using the TVS diodes. I am using 5V coils vs. something higher, so the inductance is lower and theoretically the speed of field collapse. along with 10V TVS diodes. I used the bidirectional ones so I didn't need the reverse diode, like you'd need if using a regular zener. it will be interesting to see what happens on your testing
That's the magic of Logic circuit, if you can make a gate you can build or replicate anything, relays or a feature in a game, in all realms its possible to create great stuff. Nice Job ❤️
Totally - that was a big part of why I did this as I wanted to learn discrete logic circuits - I found relays are a good way to be able to experiment and they are sturdy enough to handle any wiring mistakes along the way :)
New sub here. Im following your project very closely and really dig your desugn. I always viewed relays as iredeemably obsolete technology and avoided them in any of my professional engineering work. When I was forced to impliment some basic relay logic for a safety interlock, I got helplessly fascinated with how differently logic gates can work on relays, how a single relay is a much more powerful logical building block than a single transistor, which is only superior by virtue of speed. For a fun little challange, I tried designing an adder, which naturally became an ALU, then registers. Now I'm working on a relay computer as well, but on "hardcore mode"; an arbitrary constraint of no semiconductors except LEDs for visual feedback only (Diode logic is cheating). Currently designing PCBs while I wait for my HK19F's to arrive from China.
Genius move with the edge cards. Im totally going to rip that off at some point. Keep up the great videos!
That's awesome to hear! I was so intrigued at how something as basic as a relay could be used as a building block to larger logic circuits. The constraints are fun to manage - RAM will be a challenge to keep "period correct" but I may consider doing two routes in parallel for that one. I would be very interested in seeing your work, make sure you keep us all posted!
Oh heck yes. I want to build one so badly. You get a like and subscribe, this is such a cool project. I can't wait to see the rest, this is fantastic. It sounds so good loading and transferring between registers.
Totally ASMR for me, too. My dog goes all barky and thinks someone is knocking at the door whenever I start it up.
I love Relay Computers.
This is awesome to watch!
Thank you for watching, it will be quite the journey ahead!
This is so interesting.
I'm building an 8 bit adder (with 9 bit memory) on Vero board😫 because I sadly have no expertise in PCB Design.
I marvel at your skill in design and everything else for that matter.
I tried vero boards as well, but I'm not patient enough. Give EasyEDA a try - I don't have a background in PCB design and learned it in a few weeks, they have some good tutorials here: www.youtube.com/@easyeda2164 --- btw I'm not affiliated with EasyEDA --- I just like it because it's free!
Love this - electromechanicals feel so satisfyng :) Subbed :)
Thank you for watching and subbing!
Delightful clicky-clackies! Thank you for sharing!
Seems like the clickty-clack is what is most interesting for so many. I was fortunate enough to walk through and old tel-com centre in the 80s and it had this very familiar sound.
I’m really enjoying this series. I’d love to have a go at building this at some point!
So incredible cool. Keep going!
Thank you!
This is awesome Thanks!
You're most welcome. I was excited about this project and glad to see that it's interested so many others!
Great build! Keep up the good work
Thank you!
Super interessting. I love to see what is possible by using relays for a computer.
Another great episode! Thank you
Thank you for watching!
Excellent work! Dancing to the funky rhythm!
Thank you. The rhythm will continue to be funky!
very cool project!
Thank you! Looking forward to sharing the journey!
Watching with interest as the project progresses.
Looking forward to provdiding the updates! Thank you for watching!
Awesome. I’m your #1 fan!
Thank you, and likewise 🙂
This is epic!
This is amazing. I've just gotten into the 6502 processor, but this is on a completely different level. Keep up the amazing work 😄
I love 6502s, I dabbled in assembly on Commodore 64s! You may have noticed my use of 6502 instructions for the videos 😉
My sequencer is just essenially a rom lookup table. Output of the sequencer just activates a row in the rom, the data lines then activate various modules and connect them to the bus or send control signals to things like the ALU.
I recall a similar concept that Ben Eater used on his breadboard computer which was a real eye-opener for me. Is it an IC-based ROM you're using? In future, I'm looking at ROM being something like a bunch of DIP switches just to keep it old school.
@@dipdoting yes my ROM is just rows of dip switches. I wanted to keep it old school too :)
Excellent work and looking forward to more. Just a suggestion, you might want to mention how much power you are drawing.
The registers (fully loaded with data - all LEDs on) come in at around .96 amps. I've ended-up using relays that are .04A (.2W) each, they are a bit power hungry but I can never find the lower wattage versions.
That thing is a beast. An amazing beast. BTW I have heard 12 volt relays are better for logic because they use less current. Have you had any power issues?
I wondered that as well, these particular relays are a bit power hungry, so far no issues but I'm having to watch the amps now that there are so many boards.
it has been such a long time since I have heard that sound like that speed-run test. super fast at 15:10 and the turbo mode at 15:36, you have to go back to 1979 on a particular "commercial towing vehicle" to hear. There are many ways to do things, and they all have their pros and cons, and that's why some things are done a particular way. call it steam-punk, or relay-punk, whatever it is, I look forward to more of this project.
I see your Alien reference, and raise you, well....the same reference. I think that scene from Alien reference is embedded in me since watching the original in 1979, I'm dedicated to completing the mission.
There was an interesting Mystery tear down video floating around.. can't remember who by.. that wound up being a Home made Japanese sequencer for controlling Christmas tree lights from the early 1960's.. the logic elements comprised of glass reed switches with hand wound coils around them to create tiny relays. It makes me imagine some sort of hand made steam punk deadbug relay copmputer.. like a living dual use art and science sculpture.
Great work! Was interested to see schematics before designing pcb.
I'll definitely share out the schematics once the build is working!
Thank you for sharing your journey into relay computing. Have you given any thoughts to how to implement self-checks or raising exceptions when a fault occurs with a particular relay? Will you be able to implement any fault detection or a power on self test of sorts with the ability for any given card to raise an OK status? So many interesting things to think about during the architecture design!
That's an interesting concept, like a BOOT ROM routine that runs some basic check routines (transferring values, compare results, memory test etc). Would certainly make turning on the machine more interesting at start --- right now there's just a single "click!"
Good thing solid state came long. Can you imagine playing GTA V in that racket?
I can't even imagine it running MS-DOS 🤣
Just to spoil the otherwise perfect run, we have an 'Auotmated Testing' at 14:04.
Haha good catch! I noticed that only after I uploaded-of course...I guess my spell-checker isn't so auotmated, either!
What criteria did you use when selecting the relay make and model? As the number of these relays increases, this factor may become crucial. I remember looking for relays to make a simple astable multivibrator analog, and the endurance (on/off cycles) varied a lot between models.
My quest for relays wasn't very scientific - I started with a pack of 5 relays from Amazon - my only criteria was that they were 5V and would fit on a breadboard. the datasheet claims a lifespan of 10,000,000 cycles --- we'll see!
Any particular reason you are not populating the back-emf diodes?
maybe he bought relays that already contain diodes
That's an easy one...I didn't have enough diodes on hand 😄 just enough for the pulse generator. More on order, will need to populate on all my boards so far! So far seems to be running okay without them but don't want to build too much further until they are all installed.
@@dipdoting Well, just a heads-up in case you were not aware: Adding single-diode back-emf supression will (likely) slow down the realease-time for the relay by a factor of 2-3 times. So be aware that adding the diodes might slow your comupter down significantly. There is another method using a diode and a zener diode in series which gives faster release time. It might be worth experimenting with Arduino and your relays to figure out the best way forward.
@@smudgerdave1141 That's an excellent point! In the previous video comments someone mentioned that they leveraged that same delay to create simplified latch for their registers. I've been using 1N4148's thus far - maybe once I install them all I won't be doing "turbo mode" anymore!
@@typedef_ That would be handy!
if/when a relay fails, can you identify and replace it? or would you swap out the whole board?
I had that exact problem on a previous board. You can test relays individually (from the bottom side). I'll try to demo that in the next video.