I'm very excited to see this new module. Thank you for these amazing videos.

I'am soooo exited for this one. are u going to remake snake for vga?

@@-lolus- There might be a "Snek 2.0" by the end. But only so I can keep Snek around for posterity. I have higher goals.

Was driving, missed it!

Please no Premiers! It’s annoying to have video listed in you queue which are not yet playable. When you release the video it will pop up soon enough! I unsubscribed all channels that do this stupid premier stuff. The serie will be very welcome! Always like your videos very much.

Well hopefully order yourself some breadboards ;-)

Actually 😄😄

Glad you are finding it interesting! Good luck with your build!

There were a few games in 320x240 256, even tho it wasn't a "standard" VGA resolution. Memory limitations and square pixels made it attractive.

It will get more complicated before I'm done!

Thanks! Glad you found it interesting.

Pleased I finally got this video uploaded!

Thanks Adam! Hope it doesn't disappoint!

Thanks Scitoshi, it's going to be an interesting Journey.

Thanks Ced! Hope the rest lives up to expectation!

Thanks! But it will get a lot more complicated over the coming weeks!

Thank you very much! Glad you found it interesting.

Thanks Seon. While in many ways this series will be a natural continuation of the cpu build the visuals will give far better progress feedback than I was able to demonstrate during parts of the main build.

Thanks, hope it meets expectations.

That! I spent a while knowing roughly where I was going with the vga circuit but not seeing the best steps to get there in terms of videos until I hit on that idea.

Thanks! I was pleased with the 3.14mhz, but I'd had it running at 2.5mhz before and I'm quietly confident it can go a little faster.

Thanks Detlev. I've been looking forwards to this bit for a long time.

@@weirdboyjim Could you please share the test code and updated code for generating the pipe roms? would be great, thanks!

Hope you enjoy!

Now your making me feel bad.

But you can see in the picture the extreme complexity of the first step, and it's massive chip count.

@@weirdboyjim don't feel bad. Your content is amazing. I'm just glad I don't have to wait until tomorrow. Yup I'm intrigued by this chip count. I just hope that's not an MCU. ;)

@@weirdboyjim totally unexpected and awsome! Welcome to the club of bitbanging VGA using your own processor! Cant be many folks who have done that. And no, it did not disappoint. :)

Always worth aiming high! I'll be clear though, to say 640x480x24 implies a true color frame buffer. That would be nearly a megabyte of video memory, I'll be pulling trickery to fill the resolution like old style consoles/micros.

@@weirdboyjim Yeah. I understand. You'll generate the image on the fly from tiles, sprites, etc. Similar to the TMS9918, but with scrolling and better output specs.

Glad you found it interesting!

Thanks! Glad you enjoyed it!

Thanks! Glad you are finding it interesting.

Thanks! Glad you found it interesting!

Hope it lives upto expectations!

@@weirdboyjim definitely worth it 🙂 it's a great start for what I expect will be a very interesting series of videos.

Thanks Crul! I have lofty goals for that series, and lots of wires to make for the next video..

It was an impressive bit of kit.

Hope it lives upto expectations George!

@@weirdboyjim it seems like you have a serious plan for this VGA stage! Nice! Hardware sprites are gonna be interesting!

Glad you liked it. I try and explain things as clearly as I can but I obviously can't cover all the basics in every video.

@@weirdboyjim I have of course some electronic knowledge (basics) but mostly on the hardware side, programing is not my domain but seeing hardware and software collide to make something really cool is just fantastic to watch :) I am definitely learning things

Them spectrum didn't have them, I didn't actually do much programming with sprites until the game boy color.

When I first started learning how to make hardware sprite capabilities, I was shocked at just how less complicated than I was expecting it actually was. It's pretty much just shift registers pushing data onto scanlines. That's about it. Who would have figured?

Glad you like it Henrik! Yeah, I very much going for the spirit of the early micro and game development era with my projects.

@@weirdboyjim Again: Loving it and you very much "owned" a new follower! 😀

Hmm, that wouldn't be too difficult but on an 8-bit cpu it would take a while.

@@weirdboyjim it could make for a couple episodes where an application specific unit that does fixed point arithmetic (multiply and addition) might be added to speed it up. It did take some time on the C64, but was 😍 to see.

When I think of fractal demos, I think of my old family 386. It took a while then, too. :-)

I think you missed some of my comments. The Latch is only a temporary measure to get a simple circuit working. Later videos will add a framebuffer, the sprites will be hardware as well.

Actually I made a better one while waiting for the premier to start. Same hardware/software but it a little bit of dithering on the image made it look much better. Something for the next one anyway.

I like to user words like "Perseverance" and "Determinism" rather than "Masochism" ;-)

Thanks Benni.

Glad you like it!

Thanks David. One of my ideas for a future build is to try and make an ultra simple (But practical) 8-bit cpu that it would be much easier for people to replicate. But this build is far more in the "overly ambitious" side of things.

I know right! :-D

Thanks Retro Marky, pleased you found it interesting.

Lots of people have nostalgia for the old Specy. The π MHz thing was not deliberate and it breaks down if you work out additional digits, it's just the vga pixel clock divided by 8!

@@weirdboyjim Yeah I got that. .You quoted 3.14 the first time, then 3.146 later, but let me have my math nerd dreams OK :-) Looking forward to starting this series from Episode 1.

@@daviddawkins if you used 25.175/8 to calculate the surface area of the earth you would over estimate by roughly enough for an extra Greenland. ;-)

@@weirdboyjim don't worry, I always use 22/7

On the older pc cards double buffering was always a horrible compromise due to limited memory. Even with a true vga card there you couldn't do 320x200x256 colour mode with double buffering by standard. There was a way of doing it but putting the memory into a different mode but the addressing became weird. I'll not be doing double buffering for this build, I want 60fps update so it's better to spend the address space efficiently creating the tools to do that.

Thanks Olavl! The plan does include something that could be used to display character data, but it will be a few videos before I talk about that in any depth.

@@weirdboyjim I know there are several solutions for that particular problem and I'm extremely curious how you are going to address it. I'll wait patiently for that, just hurry up will you ;-) (j/k) Another question if I may: is it at all possible to port existing games/software to your 8-bit computer provided you have the source? Or is the CPU too different from other architectures that this would be impossible?

Thanks Das!

Thanks! Hope you enjoy the rest of it!

Well spotted, that's an interesting question with a long and mundane answer. In truth it's not 60hz, it's 59.94hz! That's the standard for NTSC refresh despite everyone saying 60, in truth until recently almost everywhere refresh rates were described as 60 it was actually 59.94, this is legacy compatibility with NTSC that was deliberately out of sync with the US mains 60hz rate to prevent static artifacts in the color.

Sprites definitely help getting some interesting motion at high update rate. And they represent an interesting challenge if there is any kind of transparency (which there will be)

I've talked about banking before. I'm not planning on doing any in this series, I'm more interested in fitting it all into a small amount of memory as a challenge at the moment.

This setup is much more akin to how the Atari 2600 does video than the NES PPU, isn't it? The CPU is basically bitbanging the signal directly.

@@StefanNoack I think Chris is refering more to the project goals than the first circuit in this video. The 2600 was much more than bit banged video, it had basic sprites.

About that high resolution goal...

Oddly enough I've been looking at that kind of interface from the other side. A lot of VGA display modules have that interface, and a board for converting from a regular vga input. When I design my output circuit I'll include the dac and vga connector but I'll look into adding the digital output header as well. Might save me some space if I use one of those modules.

I may get around to the Sieve video quite soon actually.

You ain’t seen nothing yet! ;-)

Glad you liked it Mr Wizzard!

Yeah, people made attempts to reproducing the demo on every computer around. The BBC one was very hacky.

@@weirdboyjim it was... you could get back to the BASIC prompt and the screen would keep bouncing.

Glad you like it!

It would be cool to work with him,

That's my homebrew pipelined cpu. This vga project is one of a number of smaller series making add on modules for it. kzfaq.info/sun/PLFhc0MFC8MiCDOh3cGFji3qQfXziB9yOw

I have nearly 100 videos in the playlist for the main cpu build. Is that what you are after? kzfaq.info/get/bejne/ac94lMpl0JrddZs.html

@@weirdboyjimYep thanks dude you are great

The common basic logic series (LS/HC/HCT) are all fast enough, but only just. What they are not is fast enough to make sloppy design ok, in my cpu and other cpu designs I've seen on youtube there tend to be chains of logic that are required to settle within a cycle so the maximum clock rate is reduced, to make the vga work at the target rate it will be necessary to carefully track this. You are right that a simple ladder would definitely be a problem, a well made R2R ladder can be made to work but of care with resistor selection etc.. will be necessary "next closest value" and "10% tolerance" are not going to cut it. I'll get there in a couple of vids and you can judge my success or post your "I told you so" ;-)

I don't think it's practical. My pixel output loop (that gives me rubbish horizontal resolution) is unrolled at 3 cycles per pixel. The best I can do on z80 is 21 cycles so you would need greater than 20mhz to match this. In a few videos I'll have a frame buffer that will be much more suited to interfacing to something like that.

Those are printed with a "Dynamo Letratag", really useful little thing. I label lots of my storage boxes, chips etc.. with it.

@@weirdboyjim Nice, I ended up just using sticky paper and my regular printer, I figure it works fine too. Less spending! I like when I figure out cheaper solutions like this.

My feature set is actually pretty tough to compare to the vga card sequence, but when I say VGA I was more referring to the output video/monitor standard.

The 10/10 at the start makes me think this is a complement, so thanks!

@@weirdboyjim it is, don't worry, heheheh! I'm just messing around, this is great stuff. I always like to see people making these kinds of things. Makes me wonder what I could do if I had the knowledge. This alone seems like a wonderful learning experience.

As in having 2 ram chips that are switched between video and CPU access

Probably would need cloning to happen at vblank through some blitter

See what you think of the system I implement in the next vga video.

I've been releasing bits of schematic as I make the pcb's, you can see a number of them on by easyeda profile (link in the about section of the channel).

35 teraflops? Just as soon as I can get the observer down the gravity well of a nearby blackhole.

Actually many vga cards do have support for both of those but the need was very much reduced for it when CPU’s and clock rates got so fast it became easy to redraw everting.

@@weirdboyjim Ah, do you have an example for a vga card supporting pixelwise hardware scrolling and more than one sprite?

@@alexany4619 simple hardware scrolling just requires the ability to set the display base address and I think they can all do that. Sprite(s) are usually just exposed for the mouse cursor these days so maybe not plural in the common case.

Did it even exist one single VGA-card which supported more than one sprite? Was hoping to find a card with the Yamaha V9990 which should fill this gap but it seems, this VDP didn´t make its way into PCs.

You joke, but I have thought of writing hashing routines for the cpu as a demo of how they work.

Thanks Kipper!

I haven't touched FORTH since university but the kind of implementation you would put on an 8-bit cpu would not be suited to the kind of cycle precise programming I need to do here for the early VGA implementation.

@@weirdboyjim good point, I was thinking more of general hardware development. Just the ability to interact with a live system is extremely useful. The code, burn a ROM and test cycle gets old very quickly. Having said that, you hardware is outstanding.

My breadboards bring all the nerds to the yard!

Hallo! :-D

It’s more complex now 🤣

It's not as easy as it sounds, the protocol maybe simple but the clock rates involved are much higher (As it's a serial protocol, for 24bpp it will be at least 24x higher) and that puts you in a frequency range where it's just not possible on a breadboard.

@@weirdboyjim It's not 24x higher, but only 10 (DVI and HDMI have 3 separate data lanes for R, G and B). It's 10x and not 8x due to 8b/10b encoding. But there are transceiver chips like TI's TFP410, which handle all of it internally, accepting a simple parallel in at pixel rate (25 MHz in your case for 480p) and sync signals. 25 MHz is probably a tad too fast for a breadboard anyway (especially for 24 bit parallel bus), but it's about as slow as it gets for full-blown 480p and it's a single-chip solution. You can build a breadboardable adapter for that chip if you insist on a breadboard (even though your final solution seem to involve a custom PCB, so such frequency is not a problem). And data lane speed (250 Mbps) for DVI/HDMI is not very high so you don't have to worry about exact trace impedance match either. I've seen 1080p transmitted over loose jump wires with my own eyes! :) Anyways, thanks for the great videos! You have a new sub!

@@asmi06 Ahh fair, I hadn't looked close enough at the spec to see the 3x lines. But a specialist encoder chip would put me off it as I'm trying to keep the BOM short and simple.

@@weirdboyjim Of course it's your call, but I don't see how else you can achieve full 480p in true color, which you stated as the end goal. Unless you resort to FPGA like Artix-7, which can do TMDS natively, but using it will kind of make the rest of your CPU redundant, as you can stuff it inside the very same FPGA :) And it will likely run a lot faster too. BTW - have you considered going for something like Risc-v ISA, which seems to be all the rage currently in the hipster community?

You know how to give a compliment flarn!

@@weirdboyjim Actually I was referencing Ben Eater's series, but a compliment is certainly deserved!

Not sure what you mean. Are you asking where in America I am? The answer to that is that I'm not, I live in England.

Lol, Wikipedia says that is designed for 64bit machines. Might be a little out of scope.

It won't be very simple by the time I'm done ;-)

Not sure who you mean by Kevin but Ben and Luni are great creators! Honored to be named alongside them.

Lets walk before we run, like maybe try for more than 26 pixels across the screen first before we set too lofty a goal ;-)

@@weirdboyjim I was being rhetorical. I'm self taught in C++ for 3D Graphics and Game Engine Design, to Hardware Emulation, to Circuit Design to CPU and ISA Design. I was being sarcastic and dramatic about it. I have a very good idea the amount of complexity that goes into making the top of the line modern GPUs. They are far more complex than a multi-core CPU!

I actually just bought a vga to hdmi convertor so hopefully I can capture the output to add in as an overlay. Actually generating hdmi from a breadboard I don't think could work, it's a serial protocol so the clock rate would be far higher than is practical on a breadboard, at least in my understanding.

The parrots are cropped from "Kodac Image 23" from the Kodak image set, a group of images that have been widely used for display and image processing tests for since the early 90's. I think I first used this particular parrot about 25 years ago for a university project on palate mapping and dithering. I have a lot of respect for Ben's work, I've mentioned it several times in my videos but I have more than 100 videos out now and it wouldn't be practical to mention it in every video. My CPU project probably wouldn't have happened without Ben's but the design is very different. The VGA project here was roughed out before Ben's first video on the subject (There are passing references in my earlier videos) but my progress has been slow.

@@weirdboyjim Oh that makes sense. Thank you for the answer, and sorry for the accusation. I didn't know that you have mentioned him before, as I just found this video, and it seemed pretty interesting. Actually, as it turns out, it is interesting, and I really like the EEPROM for decoding the sync counter, that would have been my choice too, if I had money and time to make such a project. I'm very interested in the progress, especially the RAMs and how the CPU is gonna handle it. So keep up the good work!