- 9
- 35 076
DiPDoT
Canada
เข้าร่วมเมื่อ 12 ส.ค. 2023
Welcome to DipDot!
This channel is mostly to chronicle my design and build of a relay computer and other vintage computer interests. Although I've been programming modern digital computers from the 80s onward, I've always been fascinated with vintage computing so this project is one of many on my bucket list.
This channel is mostly to chronicle my design and build of a relay computer and other vintage computer interests. Although I've been programming modern digital computers from the 80s onward, I've always been fascinated with vintage computing so this project is one of many on my bucket list.
Relay Computer - Prototyping Board & Instruction Register
I've reached the point where I want to experiment with different designs, and I needed something with more capacity than a standard breadboard. This new prototyping board allowed me to very quickly set-up an instruction register and even add the Instruction Fetch Cycle microcode!
Chapters
0:00 Intro
0:32 New Program Counter Overview
1:21 Instruction Register and the concept of Prototyping
2:21 Design Time!
3:10 New Prototyping Board Overview
5:06 Assembly Montage!
8:29 Instruction Fetch Cycle
9:48 New Prototyping Backplane
10:20 Testing
14:17 Outro & Speed-Run fade out
Thank you for watching, and as always I welcome any feedback or ideas for future projects!
Music
Nine Lives - Unicorn Heads
Komorebi - Futuremono
Chapters
0:00 Intro
0:32 New Program Counter Overview
1:21 Instruction Register and the concept of Prototyping
2:21 Design Time!
3:10 New Prototyping Board Overview
5:06 Assembly Montage!
8:29 Instruction Fetch Cycle
9:48 New Prototyping Backplane
10:20 Testing
14:17 Outro & Speed-Run fade out
Thank you for watching, and as always I welcome any feedback or ideas for future projects!
Music
Nine Lives - Unicorn Heads
Komorebi - Futuremono
มุมมอง: 3 494
วีดีโอ
Relay Computer - Memory
มุมมอง 4K6 หลายเดือนก่อน
I'm exploring different memory options for the relay computer, from old-school capacitor-based to a more modern Static RAM that has way more memory than we'll ever need. Chapters: 0:00 Intro 0:47 Exploring "old-school" memory options 2:14 Capacitor-Diode Memory - Prototype demonstration 4:29 Modern RAM - Deep-dive into the 62256N 5:37 Modern RAM - Prototype demonstration 9:05 Isolation - A good...
USB Keyboard Interface for the TRS-80 Model II - Part I
มุมมอง 4366 หลายเดือนก่อน
As I was searching for a TRS-80 Model II, I found so many there were being sold without keyboards, with the keyboards being sold separately for more than the Model II itself! It got me thinking...would it be possible to build a USB keyboard interface for the Model II? Challenge accepted!! Thank you for watching! Chapters 00:00 Intro 01:06 Welcome to the machine 02:22 Oscilloscoping the keyboard...
Relay Computer - Incrementer
มุมมอง 3.1K7 หลายเดือนก่อน
This 16-bit relay incrementer is based on a generic half-adder circuit with some additional goodies for Load and Select operations to and from the address bus. Ping me on Discord: discordapp.com/users/390998876875915276 Thank you for watching, and as always I welcome any feedback or ideas for future projects! Chapters: 0:00 Intro and Recap 0:21 Why do we need an incrementer? 2:54 Binary Additio...
Relay Computer - Sequencer
มุมมอง 6K8 หลายเดือนก่อน
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/390998876875915276 Music: Broken Drum Machine - Godmode Kreuzberg Nights - Futuremono Drifting at 432 Hz - Unicorn Heads Thank you for watching, and as always ...
Relay Computer - New Register and Backplane
มุมมอง 16K8 หลายเดือนก่อน
Although my first register worked as designed, I soon got the feeling that it wasn't going to work out - coding and cabling would have been horrendous! Fortunately, this led me to do some more research and finding a much better solution for both the registers and how it will all tie together. Ping me on Discord: discordapp.com/users/390998876875915276 Music: Space Jazz - Libre de Droits Kamogaw...
Hellorld! on the TRS-80 Model II (Running CP/M)
มุมมอง 1.1K9 หลายเดือนก่อน
This is my entry in the @UsagiElectric "Hellorld!" challenge, using a late 70s TRS-80 Model II running CP/M. The code is written in CP/M assembly (Z80-based) and was coded using the CP/M DDT utility. Music by Colony Three - Used with permission Chapters 00:00 Intro 01:29 Inspection and Cleaning 03:17 Floppies - The good, the bad... 04:03 Start-up into CP/M 05:24 Getting out the DDT 07:40 Enteri...
Relay Computer - Register Testing
มุมมอง 1K10 หลายเดือนก่อน
This is my first custom designed PCB circuit, which is a relay-based 8-bit Data Register. It consists of 8 1-bit relay latches, 4 relays to control gating of I/O to the data bus, and 1 relay to "reset" the register value to all-zeros. I use an Elegoo MEGA2560 (Arduino compatible) and some Elegoo 8-Channel Relay Modules to test the register at higher speeds.
Roland W-30 LCD Backlight Replacement
มุมมอง 30510 หลายเดือนก่อน
I'm finally fixing the defunct backlight on my Roland W-30, it only took me 20 years to get around to it! Music: Entanglement - Colony Three (Used with permission) Note that a Roland W-30 was used in the making of the background music on this video.
Very interesting that it signs on as CP/M 2.1 -- I've been asking around online if that version even existed. Do you happen to have a disc image of that boot floppy?
I'm just in the process of picking up a FREHD and once configured I'll make an image for you!
donde puedo encontrar esquematicos
Publicaré los esquemas una vez que la computadora de relé esté terminada. (Lo siento si esta traducción no es buena, usé el traductor de Google.)
@@dipdoting si está bien la traducción
What a cool project!
Thank you!
Will the data bus gating to PC become useful when implementing a JMP instruction?
The architecture of this machine doesn't load the PC from the data bus directly as the data bus is only 8 bits. But, we can load X and Y with two 8-bit values that become the 16-bit XY value that can be transferred to the PC via the Address Bus.
Juts discovered this channel and wanted to say how much I love these videos.
Thank you!
What do you think about using latching (bistable) relays for memory?
Could definately use those, they are just pricey - unless you know a good supplier 😬
If you used two relays per bit, you could have the capacitor memory without the separate clear line. The first relay would select between ground and vcc, the second relay would take your write signal, connecting the first to the capacitor. So, write + zero data = ground capacitor, write + one data = charge capacitor. You would power write on read as well, for your 'refresh'.
Hi !!!!, u are great !!!!, I´m from Argentina, I have my TRS 80 MODEL II but unfortunally I have no keyboard, it´s a great project to replace the original keyboard or damaged one, GO AHEAD !!!
take my damn money! I want one! (seriously)
and love the logo - got merch??
Merch has crossed my mind 😉 I'll try to come up with something relay interesting. As for the boards themselves, I'm going to post some designs soon once I find a good site.
Sure great idea ! 🙂 But you should add some capacitors to buffer the voltage drop over your various 5 volt lines for these bunch of relais !
This is really a thing of beauty :) Its really fun and addicting building up an SBC or home designed computer, but doing with relays just is so fun. And insane. But mostly fun :)
The process has taught me a lot in both design and low-level CPU functions - it is a bit insane and I'm always surprised when I plug in a new board and it actually works 😁
enclosure, active cooling ? internal or external power ? com port ?
Lots to think about for all of these - likely just a good old fan for cooling, internal power supply, COM port running a 1 baud 🙃
There is something musical and pleasant to listening to those relays.
Thanks for sharing, I have been waiting to start my own project. Going to university now so I can finally start something like this and this is really good motivation and insight :)
For what it's worth, I started with a cheap set of breadboards, a few relays, LEDs , resistors, jumper wires and a battery. Oh and I guess diodes, too...I always forget about those 😬 The only thing I'd recommend is to buy good quality breadboards - they are a bit more expensive but they are well worth it!
@@dipdoting I have had to experience first hand the horrors of cheap breadboards, having to troubleshoot a circuit only to realize halfway through that one needs to troubleshoot the breadboard too. If there is one thing I'd happily pay a premium on it would be breadboards haha Cheers.
You've inspired me to FINALLY build the relay computer I've wanted to build for years! ALSO nice intro!
Thank you! The intro was also a lot of fun, love doing stop-motion stuff! Glad to hear you're going to build one, let me know how it's going!
@@dipdoting Well it's a much more complex design that probably would be best left to TTL. The ALU alone is about 87 relays so far. It's my 5th or 6th scratch computer design and I put a lot more effort into making it capable than I did into making it small. We'll see how much I regret that later on!
Like the line in Jaws. You’re going to need a bigger backplane. I thought of this before you showed the ribbon daisy chain setup. Well done. Following with great interest. Charlie in Virginia.
Haha I was so close to using the line a couple of times but was worries no one would get the reference! I'm going to squeeze that into a future video...thank you for following along!
what Wirewrap tool do you have, ive been searching for one, but couldnt find the one i need. yours look like exactly what i need
It's a Jameco Benchpro WWT-100, and inside the handle there's a wire stripper as well.
I dont really like the idea of the CMOS ram chip. its so out of place. could we come up with something kinda period correct? idk, i dont think im smart enough to think about something better tbh...
I hear ya, it feels like cheating to use a RAM chip --- In behind the scenes I'm working on capacitor memory so that should be interesting. I'll probably need a whole additional enclosure just for the memory!
I like your prototype board. With TTL CPUs people store the microcode in an EEPROM, but you can't do that. So it will be interesting to see how you build it out of relays. I suppose a diode ROM is possible.
Yes, it makes for an interesting time decoding the instructions, for example the micro-code to transfer a value between registers will take ~10 relays.
The sound it makes reminds me of teletypes. If your machine can run at 10 cycles per second it can load programs from a 8-bit punched tape reader, such as one included in model 33 ASR teleprinter, or a from a separate unit (much smaller than a teletype)
I LOVE the sound of teletypes; having one is on my bucket list. Always been fascinated with how they are mechanically synchronized and actually passed serial data so many decades ago!
Love the new prototype board design!
Thank you!
Very interesting to follow. Long time ago I intended to write a paper (in history of technology) about the first Swedish computer BARK (you can find an article of it on Wikipedia in Swedish, but make an automatic translation to English as the English version doesn't really have content at all). It was all relays and some of the documentation could be found at the national archive. Some were still under seal (much military hush, hush). Always wondered how it worked, and now I can at least imagine how!
Wow! Thank you for that -- In all my research I have never read about this BARK before! 32-bits, 50 registers and 8,000 relays!!!! What a monster! I hope that's in a museum somewhere!
The production value keeps increasing :D
Thank you for noticing - trying to up my game with each video 😎😬
Is there a particular reason why you didn’t hardwire the gnds for the relays?
You don't always want a relay coil wire directly to ground on one side. One example is doing XOR on the coil where you have one source/sink input to each side of the coil. If one of them is pulling to VDD and the other to GND, the coil energizes.
Actually, they are all grounded --- I just kept the pins there for symmetry. Originally I was thinking of not using a ground plane because sometimes you may want to activate the relay using the GND (like from a Darlington - that's what I did on the Static RAM memory card).
always excited to see more progress!!
Thank you!
Great work. Just a query - at 14:23 on the backplane it looks as if the reservoir capacitor is doming out a little, could it be failing? May be worth checking/bearing in mind if you get errant behaviours.
Good eye! I'm thinking I'll need a larger capacitor...there'll be one on each backplane to split the load.
What's the smallest instruction set you can get away with?
Google the PDP-8 and take a look at its instruction set. It had eight instructions, one of which allowed embedded microcode. Theoretically it is possible to build a single instruction set computer using conditional subtract (SUBLEQ), but no sane person would want to program it.
I have also done a single instruction computer, but my instruction was copy. Everything was mapped to an address and shared the same bus.
@@awesomecronk7183 that sent me down a rabbit hole of triggered transport architectures. I have never heard of that before.
I guess it depends on what we want it to do. If the only instruction was a "NOP" then it would just happily click away with the clock. Like what @mheermance said, probably around 8 minimum to be able to do some interesting stuff.
This is starting to take shape, the prototype board is a very good idea.
This was interesting, as always. Keep up the good work!
Glad you enjoyed it!
Aww yeah. Time to open a beer and watch this :D
I have heard that flyback diodes decrease switching speed, but increase contact life due to less arcing. Also, I think semiconductor RAM and ROM is fine.
That's a great idea for a couple of experiments - I've wanted to try different diode types and their effect on performance.
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.
This is impressive. Do you have any schematics posted? I would like to read them to understand it more fully.
I'm currently searching out a blog space for this purpose - fully intend to start putting out some of the schematics and pcb designs.
Sony ZV series cameras have a very good quality for their price, try that.
Thanks - I ended-up with a Canon Mirrorless - hopefully you'll see some improvement to resolution in the videos.
Fantastic project and video! The sound reminded me of the old cross point switches used in telecom even up into this century (although, much less than in the early to mid last century.) keep up the good work!! I’ll be watching, of a certainty.
Thank you!
(cheers from Italy) I appreciate this experimenti! I'm waiting the episode 2! The past week my friend Alessandro, a retro enthusiast like me, found a Model II without keyboard, near at the entrance of a graveyard... a little weird! The computer is in working order. If you continue with this work, you will help me! Well done!
That's a great find! Model II keyboards are expensive, so I'm definitely going to keep working on the USB version!
Very cool!
I never get tired of clicking relays
Didn't the electromechanical circuits in for example (pre solid state logic) pinball machines and jukeboxes mostly use latching based memory? Is that strategy not really usable in a general purpose computer?
Yes, they did, and this relay computer uses latching relays for the registers to store values. Great video by Technology Connections about pinball and relays here: th-cam.com/video/ue-1JoJQaEg/w-d-xo.htmlsi=L7mgr5G5tZpTFN9Z
Great work! Really interested to see how the capacitor diode memory goes
Thank you!
I used a few relays to make a keyless ignition on my motorbike in the 1980`s. No one could work out how to start it. Even got stolen twice and they never got it running.
I wonder how this computer would handle 8-bit paper tape...
Paper tape would be perfect for this computer - The FACOM relay computer used a super-wide 72-channel version. Would be nice to get a hold of a vintage reader/punch unit to experiment with.
Capacitor memory? You mean SDRAM.. It must be refreshed by the memory controller fairly frequently.
The goal is to refresh at each read cycle. For longer runs I'll need a ROM routine or something that refreshes at regular intervals. Trying to experiment with different sized capacitors to find a good balance between size and time needed between charges.
The clickety-clackety sounds from the relay - well I think it is so soothing - and probably not for hours and hours. Great video.
Thank you! I can't imagine what it would've been like working on a large-scale relay computer like the FACOM...would be cool to watch but I'd need to write the code in another room!
The first PCB I ever sent out for production was the A/D Register board for this relay computer. It had a few mistakes but I was pretty jazzed with how well it came out. I designed a daughter board the uses simple pin headers and a socket to plug into the main board at a right angle. This makes the LEDs much more visible. I also went with surface mount LEDs and resistors to make the board smaller. I'm intrigued by the capacitor memory idea but isn't it still one relay per bit? I'd imagine you'd be limited to 64 bits per board at that rate.
That's great! I thought about using right-angle for LEDs but my intention is to have everything in a case and have a front panel so they are for "debugging" purposes - at least in my mind. For Capacitor memory we'd need one relay for every 8-bits (capacitors) to enable a byte for read/write. I'm playing around with PCB designs, and I think I'm going to need a bigger boat...er...board for capacitor memory.
Can't wait to see you run a program to blink an LED 😊
Just for fun I'll have that as a front control panel option --- one blinking light! 😂