Hi! We love vintage computers here on the Eevblog, but it gets better. This really isn't a vintage computer, but it's a do-it-yourself TTL based microcomputer called the Gigatron and we're going to check it out. We're going to assemble this thing. it is a kit and look at this that's beautiful.

All the individual chips sold it on to the board. and yes, there is no microprocessor on this thing. There is simply the ROM Where's our ROM Check it out. There it is.

We've got a ROM and we've got a our six, two, two five six RAM Absolutely classic but everything else is TTL Oh love building this so thank you very much! Walter and Marcel Who designed this thing and look at this comprehensive manual we get with it I'll link it in down below if you want one of your own and they've developed this thing from scratch. If you like that. Talk about the was famously built The Brain Breakout RK He gave me 44 off-the-shelf chips. There's Marcel and Walter Good on you guys.

This is fantastic! I Love the manual. Check this out. How to use this manual Crash course in electronics: How to read your resistor color codes, how to identify all your symbols and your caps and your ICS and everything else. They've gone to an awful lot of trouble so this would make an awesome beginner kit.

It is so comprehensive. Unbelievable. like a through-hole soldering beginners kit. They teach you how to solder and do everything else.

bend the leads. There you go. I Had the Old Fashioned Squeezy I Probably still got it somewhere since when I was a kid. The old fashioned squeezy thing to dil squeeze dil pin align a thing to because when you buy the chips they come with the splayed leads like that and you know now I Just like just roll them on the thing you know, hold your tongue at the right angle, roll it on the bench and she'll be right.

but ya have one of those and here we go. step-by-step assembly instructions. This is absolutely brilliant. It's off.

This is one of the most comprehensive instruction assembly guides I've seen and I believe it is all open-source hardware. I Don't know about the license for it, but anyway, check it out. down below, we've got the full schematics. Fantastic.

Just guys at the original, it's at the original prototype on breadboard. Oh yes, you win the Internet Fantastic. And then we've got some major is a wire wrap that must have been a wire wrap version. Wow, this is great, but they've even put in the two audio line level stuff.

Interesting. Anyway, simulator. it doesn't get any better. Anyway, let's go build this puppy.

I Absolutely love the case it comes in. Look at this Nice. Yeah, that's yeah. it's a nice wooden case and then we've got the see-through cover on the top.

so you see all the circuitry and you know I'm sure it's got some Blinky LEDs in there as well and it even comes with a old school. what is this one of those Nintendo controller e things so we can play games? Yes, cuz it does have a whole bunch of stuff built in so it should just start power up and play games. They all should be programmed into the ROM the operating system in quote marks. um, whatever that is.

I'm sure they've got detailed info on all that sort of stuff, but I Basically, we're building a microprocessor just out of seven four series logic. Brilliant. I Tell you what. I like the layout - that's actually quite efficient.

You can see it like most of the leave vertical routing on the top side. here. this is only a double-sided board, so you know laying out this one if you want to task. maybe they've got the what did they use a Eagle or something if they got the file.

So try and route something like this yourself. it would be an interesting exercise in optimization. Most of the routing on the bottom there, that's a very end. there.

flood filled the rest anyway. I Like this a lot. Let's go build it. so there's our fully built gigatron.

TTL microcomputer. Look at, it. isn't that brilliant. I Love the case.

Fantastic. It took me probably two and a half to three hours to assemble this, but I was actually doing it live with an audience so interacting and chatting it would probably take you a boy probably under two hours for anyone. Do our solder a board like that and it went together a treat. No problems at all.

So let's apply power to it here. I Plugged in a VGA monitor and the game controller and you apply power and you get some blinking lights here. power lit and scanning back and forth. and what do you know we're in like Flynn Check it out and it's amazing that we can actually get this sort of output with just I.

You know, a couple of handfuls of our TTL chips, some RAM and some ROM based instructions to make our own risk and processor. Now you might notice that there's scan lines missing on here. These black lines? Well, that's actually very deliberate. We can actually get rid of that and make it solid by pressing the select button like that.

And what that does is actually because there is no video processing hardware on this thing. There's no hardware to actually generate the video. it's all done in the software via the the TTL processor itself. Then it's got to take time to generate all this graphics.

And that's the limitation of not having any. Well, what we'd call a graphics card these days. But back in, you know the times of the 8-bit computers, you'd have a six, eight, four, five for example, which was a graphics Er controller chip which would handle the graphics. So by making it solar like that, it actually works slower so we'll see that in a minute.

But yeah, so it just leaves out a scanline. So during the black periods there where there's it's not displaying it, it has more time to do processing of your actual program. and if we want to reset the PC we can just hold down. Now start at any point like that and it will actually I get us back to the screen.

So if you're in the middle of a program, you can just exit back at any point. So what we'll do is we'll select some photos here. So let's go in and select our pictures. There we go.

and it's going to start drawing a picture from the right-hand side, but it's going to do it very, very slowly. And it's got to us 64 colors because it's got two bits per. you can see that on the resistors down there. it's two bits per red, green, and blue.

So four colors, four colors, four colors, four by four by four is 64 colors. So that's what gives us our total Y palette on here. and the screen resolution is a hundred and sixty by 120, but that can actually go up to a hundred and sixty by 480. But I'm not sure how it actually does that and you'll notice that if we appreciate now, it should actually draw that a lot quicker.

Look at that. There you go. That's so that was the difference between having it solid like that and very little time to do the actual processing. It's prioritizing the video or prioritizing process like that, but still does a pretty good job like that.

See, that's not too shabby at all. Actually, the color is actually quite nice. I Mean you stand right back and it looks pretty good. Beautiful look of that.

Great stuff. A bunch of TTL chips and this Mandelbrot set is really cool, but you can see it's taking almost 20 minutes in fast mode to actually do that. I Can switch into the Slo-mo which fills in the extra scanline there. Yeah, it's slow because it's got to run that in interpreter on top.

and then we've got a racing game if we go in here to Racer and here we go. as soon we go start, you can see the difference in the count up there when I select solid graphics as opposed to the faster processing. so we basically have to keep the car on the track. Come on, you can do it.

Press select, say it's pretty slow, wear pink either solid and we can play snake as well so me. But unfortunately that's pretty much where the fun ends with this gigatron computer. you can just yeah, you play some games like it's very impressive. The stuff they've written for this theme to get it working on just a basic bare-bones Tto Risk computer, but the only other option we've got is a loader we can't actually like.

it doesn't have a basic interpreter or anything else in there. So what it's actually doing at the moment is it's just scanning the game port over here and you can hook an Arduino microcontroller under there I'm not going to go to the trouble to do it, but apparently an Arduino microcontroller in there. you can bit bang some new like some programs in there. It's like you're loading like from tape.

like old-school cassette tape or something like that. Of course you would have to actually reprogram the ROM if you wanted them actually built in and actually save when you turn the power off. So this is like you know, the old-school tape program from the old micro controllers. but basically like, that's it.

So it's quite disappointing in that's basically all you can do with it. What? you can't hook up a keyboard? you can't You know there's no basic interpreter. There's no even just to like a a ROM like a assembly level monitor or something like that. You basically can't really do anything with it unless you want to hook up an Arduino and dick around that way.

and it just takes all the fun out of it. So therein lies the problem. Whilst it does live up to its reputation as a TT or microcomputer, that's basically all you have built is a microcomputer. You haven't unfortunately, built a personal computer.

so if you do want to write your own programs and upload them via the yard we no serial interface and you can use what's called the Gigatron our control language GCL It's actually an interpreter, so they have effectively have an interpreter running on the CPU and then it can execute the programs. of course, just like any sort of basic interpreter, these are probably gonna run pretty darn slow so you're not going to. It's not like riding in you know, assembly language and executing from the ROM in there. And there's an example program so it's you know they've got their own syntax and everything like that.

So if you want to do it, you've got to learn the Gigatron control language. I Don't see the point. Like it? Yeah, it's cute. Okay, but yeah, I don't know.

Well I Guess it's fun if you're into that sort of thing, not judge it. And if you're wondering why the Mandelbrot was so slow, for example, Well, it's A and interpreted GCL program is well, so you can actually just download the source code for that. So there you go. There's the Mandelbrot function for those playing along at home.

Go for it. Sure, you can optimize it. And the other thing. Whilst this is probably the best, if not the best assembly manual I've ever seen, it's fantastic.

It's basically all you're doing here is you're building a kit and that's all the instructions basically do. Yeah, you do get the schematics of course, and then you get the simulator code, which Is very cool. if you want to, you know, run that. but there's basically nothing else that explains like yeah, we've got the architecture block diagram, but there's no real like detail.

Come tutorial on what you've actually built here, how the computer works, how it corresponds to you, know the different circuitry on here, and how the instructions flow in a processed and and how the computer actually works. So it's really it's just a whole assembly kit and it just happens to be a non personal computer at the end of it, which is really cool. But yeah, it's an expensive amount of cool just for a do-it-yourself our through-hole kit basically. And as for the risk: I Processor itself: Well, it's it.

really is a reduced instruction set most, so it's only got eight instructions. and here's the instruction set. and you can't Really, you know there's not much variety in there to you know, do creative things and stuff like that. Sure, you can do your Mandelbrot's and you can draw your pictures and do everything else.

a brute force. but yeah, and it's not basically not compatible that I'm aware of with any other RISC processor that's being produced. It basically is its own architecture and it uses its own art programming language as well. I Just found this presentation that they did at a conference and you can watch the the actual presentation video online as well as there was with his Nixie tube watch and that's the original breakout arcade game just using our TTL logic in the Apple one of course.

And there's their original prototypes and they actually this is quite good. They actually go through and explain the the different sections with the difference, chips and and the instructions and difference between Sisk and Risk and all that sort of stuff. so this is actually quite detailed. Go in and actually check this out.

but so they probably should have included something like this in the kit, maybe in a simpler form. This is obviously a technical presentation to a, you know, a reasonably technical audience here. But yeah, all this sort of stuff should have been included as educational material. and the kid I think Anyway, it's just hidden away on the website and unfortunately, here's the sad news: it's expensive.

This thing is a hundred and fifty euros plus unless you're in, the Netherlands is 25 euros or 30 euros postage, so that's equivalent to a current exchange rate 210 US dollars delivered or 280 Australian dollars delivered. Geez, you can buy like a low-end laptop for that. Sure, you can't assemble it, it's not nearly as much fun, but and ultimately, once you build this I don't know, it's a struggle to do anything with it. unfortunately.

And at Six Point two Five Megahertz, which it does actually execute one eight bit instruction every cycle, so it's reasonably powerful in that respect. But the fact that it doesn't have any video or audio processing that's all got to be done in the software itself, Well, that slows it down drastically. So yeah, it's not exactly a speed demon. you're not going to be crunching any Bitcoin on this any time soon.

So there you have it. That's the Gigatron TTL microcomputer. Thank you very much guys for us sending that one in I Did enjoy building this thing and do it at live stream I'll link in the video at the end of this for the live stream of that should be finished processing soon and you could watch the whole for our live build or this thing I Talk about you know various soldiering techniques and traps for young players and all sorts of stuff. And no, I didn't follow the assembly manual I just followed my nose and because I thought the assembly manual was actually they said do all the capacitors first I Think that's wrong.

should have done the chips first. in terms of our hide of components off the PCB and things like that, just little things, but it doesn't really matter, just nitpicking. Just be aware, if you're I getting this thing and you're expecting like a fully fledged computer, you can hook a keyboard up to an actually program. Now it's gonna be ultimately a bit disappointing for you, but it was a fun kit to build.

So yeah, I think there are quite a few of these I keep computers out there these days up. They says different kinds through. A bit of a revival. In terms of a retro, you know TTL computers and kits and things like that? Somebody's done yes.

I'm aware of the The Monster 6502 I'm not sure if you can buy that as a Kip it's a giant 6502 processor. would have been nice to like see some art LEDs on here and like you could shift all the data through and and use it as like a learning tool to watch data shift through the various registers and stuff like that. And you know, maybe some manual clocking buttons or something like that - you know, clock it through. So it's more of an educational tool.

and at this point it's basically just a through-hole assembly kit with a fun little you know, novel little computer at the end of it. So anyway, I hope you enjoyed that video. If you did, please give it a big thumbs up. As always, comment down below and if you want one of these I Gigatron, they still do have them available.

so I'll link it in down below. Catch you next time.