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Show HN: A retro video game console I've been working on in my free time (internalregister.github.io)
2690 points by pkiller on March 14, 2019 | hide | past | favorite | 210 comments

This is the coolest thing I've seen posted on HN in years, very cool work.

I've been playing with Atari 2600 programming on and off for the past few years and it is so fun programming directly against the specific hardware. I can't help but occasionally wonder if I could piece together a similar system, but I have 0 experience with electronics. I can only imagine how satisfying it must be to actually pull it off.

Thanks a lot :)

It really is super satisfying to get this far, I still turn it on sometimes just to check if it really works.

And I also had zero experience with electronics (and I still don't know as much as I should...), so yeah I think you could piece together something like this. :)

> I still turn it on sometimes just to check if it really works.

I feel this on a personal level, albeit on my much smaller, less complicated projects. Thanks for the amazing write-up, you are an inspiration to us all.

I was a tad skeptical when I saw the title. But it looks like you really pulled it off. It took Atari engineers like 4 years ;)

Is it fast enough for multi-input / multi-player?

Thanks :)

The only multi-input game I have right now is Tetris for 2 players. My girlfriend doesn't complaint while playing it (except when I win :P), so I'd say it's pretty responsive, even with the somewhat convoluted way the CPU communicates with the PPU and the double-buffering.

I think it will work for other types of games as well. With all the hardware, firmware for the 3 microcontrollers, bootloader software, compiler toolchain and tools, I still haven't gotten around to actually make a lot of games for it.

This is crazy dude! You're an inspiration! Awesome job!

I would totally pay (~$300) to jump on a pre-packaged MOOC like course that has a batch of students working together and the course fee would include the hardware needed and access to a TA like resource (when the batch of students can't solve a problem together).

I can even imagine a part II with modern components after learning this level of basics.

Wow! Thanks for making such an interesting and detailed writeup! And using my favorite CPU too :) Definitely bookmarked to read through more times.

Z80 rules!

Thanks :)

Out of curiosity, have you thought about trying to port "real" games over to it, as in running a ROM of something commercially released? This is already really cool, but it would be nerd-cred-for-life cool if you could say "Oh, you have a gameboy? Yeah, I built my own."

I love that there is a group of people who still love the Z80!

Such a beautifully designed chip.

I was doing a little bit of Z80 work a while back, but I didn't particularly seem to appreciate its design (compared to say MIPS). Why do you think it's beautifully designed?

Admittedly, I do not have a lot of experience in other CPUs, but to me its just the way its designed. A simple syntax for assembly and the way it maps to byte values is clever. It doesn't require a lot of work to make things happen, ie "hacks" for interacting with IO. I also like how there is a separate IO bus from the data bus, which means IO doesn't take up memory. The register naming convention is simple, and having "alternate" registers is cool.

Just seems simple and cool to me.

You can hand clock a Z80. There is a certain magic to that.

I'm sorry, but what does "hand clocking" a Z80 mean?

I think GP's use of "hand-clocking" to refer to the factthat the z80 can run on a very low clock rate, to the extent that you can have a hand switch that sends individual clock pulses to the processor. This can be useful for testing purposes as well as for low power operation in embedded applications.


As the Z80 doesn't use dynamic registers (I think basically the only "modern" CPU to make this decision) it doesn't need a minimum clock signal speed to refresh the registers as every other CPU does.

This means you can rig up a push button switch and manually advanced the clock one button press at a time.

To me that's super cool. It also makes them really easy to debug.

I used to do Z80 programming in the TI-82 in high school back in 2002. This seeing the code in the article brought back some good memories.

Just ordered Make: Electronics and a cheap electronics starter kit with a breadboard and some basic components. Thanks for the inspiration.

You should check out Adafruit and Sparkfun as well. They have a lot of solid tutorials to get you started, and a bunch of inexpensive microcontrollers that are easy to get going with, as well as all sorts of lights and sensers and switches to connect to them.

> I still turn it on sometimes just to check if it really works.

I know that feeling ;)

Awesome work, dude!

There is something weirdly satisfying about doing something purely for the sake of doing it. So many people start projects hoping they can turn it into a business or gain stars in Github - you see less and less people hacking stuff together just for personal enjoyment.

I think we need more of that too. Everyone seems to be on a quest for perfection: perfect code, 3D printed casing, everything intellectualised to the nth degree. There's a lot to be said for the "rough and ready" approach of experimentation. However to do that you really need to be on a pursuit for personal gratification because the internet is a harsh bitch for pointing out ones mistakes.

“One’s mistakes.”

Agreed, this is dank. The successful wiring alone is noteworthy.

As much as I enjoy quickly building circuits on a breadboard like in many of the photos, they’re hell to debug, because there’s so much that can go subtly wrong. It’s much easier with digital than analog circuits, of course, but it still can be crazy hard to logic-probe every connection to get it all to work. I have spent far too much time fixing little bugs in breadboarded circuits. The toughest issue I encountered was when someone melted through part of a big, expensive breadboard with a soldering iron and it caused shorts on the other side of the board. I couldn’t even trust that the holes that were supposed to be connected were in that case, and I sure wasn’t going to copy over the project onto a new breadboard.

However, I’m not sure if there is an easier way to get quickly prototype electronics. Opting for more ICs and a lower BoM count helps, because there’s less wiring to do in the first place.

I would argue that with the extremely low cost of PCB manufacturing (and... if you have access to it... assembly) it's easier now to just lay out a PCB and get it made. The trick is to build up a library of circuit "modules" (like... power supply section, battery charging, video output, etc) that get copy-pasted together. Of course there's the delay in waiting for the PCBs, which could be frustrating for a hobby project (I was lucky enough to live in SZ for a while where getting PCBs back 2 days after ordering is standard). But parallelising projects can be an effective way of dealing with that, and the variety on working on different things (and the joy of getting a PCB in the mail) can help to mitigate that.

I totally agree. The reason I stuck to DIP ICs was because I could fit them into breadboards and I thought that was easier than any alternative. I was incredibly lucky on how all the breadboards were functional. And there were a few times where I would accidentally disconnect a wire and spend the next 2 hours trying to figure out what was wrong. All this without having a logic analyser and not even an oscilloscope until much later in the build (they are not that cheap). And yes the project sure is complex, too complex, but I guess I was lucky, and I'm glad it's working :).

I had a few interesting experiences breadboarding for a project of my own, for a 6502-based project. Most notable were:

- Being able to detect noise from the system clock crystal oscillator all cross the breadboard (using my oscilloscope)

- Seeing certain I/O pins float to a bit too high of a voltage, when they were supposed to be "low", probably due to breadboard capacitance

- Accidentally making an AM radio when I forgot to connect a wire on an LM386 I was testing as an audio amplifier

Things got a lot cleaner when I went to a PCB, but I did make it all work on breadboards first.

FYI: saelae makes an affordable logic probe. chinese clones are available for ~$10 and usually work with saelae's official software or with sigrok. a logic analyzer is really a game-changing tool.

More power to you for being patient enough to fight through! I’m nowhere near that good.

I'm really not that special, don't sell yourself short.

And thanks :)

Copper tape on cardboard.

Cardboard is a fantastic material. You can draw the schematic on, and then run copper tape along the schematic. It's easy to annotate, since you just need to use a pen. It's able to handle much more current than a breadboard, since the copper tape has a lot more metal than thin wires. You can solder directly to it, and with tape (or some other insulating material) you can cross wires without having them short.

You can also work with SMT ICs. Using a pair of scissors, you can make your own pads and solder to them. I connected an SO8 to read off the SPI data using copper tape. I built an amplifier using a spare Novena amplifier IC on cardboard with copper tape. And I have a level shifter done on cardboard with copper tape.

Bunnie has a good article on it here, including an example power regulator that's handling 2A on cardboard: https://www.bunniestudios.com/blog/?p=5259

When I was a lad, wirewrap was the thing. You can prototype quickly, and make changes easily too.

(It seems like it's still a thing in fact http://www.nutsvolts.com/magazine/article/wire_wrap_is_alive...)

For those interested in working with wire wrap: ebay/aliexpress/whatnot all sell old-new-stock wire wrap wire and the manual wrapping tools. Wire wrap works perfectly on standard headers, but the extra-long headers you sometimes see on arduino shields and such give you a couple more connections per pin: 5 vs 3 if I recall correctly.

It's a really nice way to work, you solder your components onto one of those pcbs with a lot of holes, solder the pins next to em, and from that point on you can wire, unwire, and rewire to your hearts content. Its great to easily be able to undo a connection when you make a mistake.

I would love to try this at some point: http://cpuville.com/Projects/Z80-wire-wrap/Z80-wire-wrap-hom...

Learned this technique in uni ca. 2004 and still use it for hobby stuff. It's nice to have a more stable, noncommittal method!

If you wrote a book explaining how to do this, teaching the concepts, etc... I think a lot of people (or at least me) would be very interested!!!

Great job

Thanks :)

I've kept this project to myself and would only describe it occasionally to some coworkers and friends. I never thought that many people would find it cool. And always thought that people with more knowledge than me would find a lot of flaws. So it's really awesome to read yours and all the other comments. :)

I don't think I could write a book, but I have though in writing other posts, giving more detail in certain aspects of the console. There's really a lot I could say about it and I only realised how much there was to say when I started writing this.

>And always thought that people with more knowledge than me would find a lot of flaws.

Firstly, anyone who nitpicks on a totally handbuilt computer has almost certainly not built their own, so their criticisms can be taken with a pinch of salt (that is to say while they may be valid, can probably be ignored... they're bust criticizing other people's work while you are actually getting on with building something) secondly if they HAVE designed/built their own computer (not just built up an arduino into a thing) then they are probably more likely to help you ("Hey, have you tried.... to get around..." etc.) than try and fault you. so the only reason to hide your project is to protect it from someone "stealing" it. but I don't think that is a concern, nor is anyone planning on releasing a new design of 8-bit computer/console that's not compatible with anything that's come before. what I'm trying to say in a long-winded way, is that this is an amazing project, and keep at it as it obviously brings you a lot of joy. my electronics projects are all currently stalled and finding the motivation to carry them forward it hard right now, so I applaud you!

> I don't think I could write a book

That's what you thought about building a video game console from scratch, and look how that turned out :) Awesome work!

Plus the blog post is effectively a draft of said book.

Just adding to the chorus saying they’d buy a kit and/or book. For branding, play on your introduction for PGG: Portuguese Guy Gaming. Either way though, you definitely should write more posts if it’s something you’d be interested in, you definitely have an excited and willing audience.

Thanks a lot :).

A kit for this console would be crazy though, too many components, too much complexity. But for a smaller version, it could be done.

Branding...yeah, I could never get a name for it, til this day I don't know what to call it, I'm terrible with names. Maybe I'll take your suggestion :).

Well, I'm glad the response has been so positive! And I'm always afraid of that too, but getting something done and out there is better than not doing anything. Plus, I think most people are supportive, and if there is any constructive feedback, hopefully it's coming from a place of just wanting to help rather than tear down.

I think most people are just amazed at what you accomplished :) I am!

Please consider writing a book or blog posts or at least something! But if you don't I totally understand, don't feel bad about not doing something requested, or anything else either. It's your life and your project :D

We are here just to support you and say thanks for inspiring us!

This is amazing. I'd also love to read a book on this. Electronics is always something i've thought was cool and played around with a little bit, but never really thought something like this was possible with a bunch of slapped together parts. I feel I learned a bunch just reading the bit od your process described in your article and it really made it feel like something accessible for the average person with a bit of technical knowledge and patience. Thanks for sharing that.

You won't know until you start. It's not about writing book, it's just about putting your hardwork in words. You mentioned in your writeup that you used to think same way about building a console.

I have zero knowledge about electronics, consoles, or any of this and I am fascinated by what you did with your free time. Please write a book and publish it here. I'm sure lot and lots of people would love to read it.

You should do both! :)

Start writing a book and keep writing posts on some of the details and use them to collect emails of people interested in buying the book once it comes out. Also, get on twitter for the same reason.

Those other Articles will help you turn it into a book :)

Great work!

I can highly recommend nand2tetris. It doesn't go as far as this post but it covers a lot and is a ton of fun to work through.

Check out the XGameStation that Andre Lamothe created about 15 years ago. There’s an eBook that goes along with it.

He wrote a handful of game programming books in the 90’s as well.

He wrote a great, thick book called The Black Art of Video Game Console Design. It walks you through making your own game console from scratch. It's a mini EE/CE program in a book. Definitely a great jumping-off point for those looking to learn this stuff.

It is sad that TAB books is no longer a thing, they totally would have published the "BUILD YOUR OWN VIDEO GAME" book. That said, I bet that you could get NoStarch Press to publish it.

Yeah, absolutely. Especially coming from a modern software developers POV. I always think it would be fun to get into electronics, but it just seems so much to take in.

Hmm. What do people reckon the price point and market is like for this? Are people still willing to pay $30 for a book, or is it more of a $3 ebook?

I would pay up to around $50 for a well-produced, high quality, and comprehensive hard copy book that documented the entire process. $30 feels reasonable for an ebook version of same high quality. What would be even cooler is if he partnered with a seasoned EE, who could chime in with contextual commentary on what they would’ve done differently and why. That would be even more valuable to me.

I would definitely buy one. And also buy the companion DIY kit.

Oh to built 20Mhz systems again! ... no picosecond timing skews to stress over, no ground plane worries, no trace-related design rule violations, no harmonic noise issues, no dynamic bus inversions to prevent victim/attacker degradation, no thermal issues... I spend so much time debugging GHz multi-layer circuit boards that I forget how "easy" 20MHz digital circuits can be. This guy's project is truly inspiring!

Thank you :)

I would love to learn more and be able to work with faster circuits like you. Yes it's way easier to work with "slow" digital circuits I had very little issues using breadboards and really long wires, that probably look cringy to you and others.

Note I put "easy" in quotes because your project was by no means "easy", especially with no tools at your disposal but the internet!

Can I ask how you incrementally tested the video circuit as you built it? Did you have a test pattern generator or something? I know very little about TV signals, I spent some time trying to wire up an analog camera and just ragequit because I lacked a good fundamental debug process.

I knew what you meant by "easy" and I agree.

Well, I think it isn't that hard to get an analog video signal going. Having a TV that took an RGB analog signal, meant that I could connect the microcontroller directly to the TV (using resistors to convert the voltage and for the color DAC).

Then all I did was get the timing right, especially with the sync signal. Along with other resources, I used this image ( http://martin.hinner.info/vga/pal_tv_diagram_non_interlace.j... ) to understand when to set the Sync signal to 0 or to 1. When using a microcontroller you can use interrupts or you can have well-timed instructions to set the sync signal on or off at the correct time, I chose the latter. The micros I used are AVR 8-bit architecture based, so most instructions always take 1 cycle, others take from 2 to 4 cycles to execute, simply by looking up in the manual I could calculate when certain instructions would execute and build a program in assembly that would generate the sync signal successfully. And if everything was right, my TV picture would switch to black, meaning it detected a valid PAL signal.

Of course, it wasn't always this easy, for example, I had a bug when I started, I wasn't setting one of the registers correctly and it took me a day to solve it, I had to look at the code over and over until I figured out what was wrong. Not having an oscilloscope nor a logic analyzer certainly made it harder.

Another lucky thing for me, was that the TV I have (an old CRT TV) is actually quite forgiving and even if I don't feed the timings exactly, it will still show a picture, so that helped.

Once I had a valid signal going I tested sending pixels to the screen, and I did use patterns to see if I had the timing right for each pixel, if I took too long switching pixels they would get wide. So I tried some checker patterns and stuff like that, but nothing fancy. I hope this answers your question. It really isn't that difficult to generate a video signal and also I was quite lucky to get it working early on.

I probably didn't do things like they should be done, but it worked for me. I would say that best thing is have a logic analyzer or oscilloscope to check if the signal you're generating corresponds to what it should be, that makes it a lot easier.

No pesky compliance issues eating into your precious timing margins...

Okay, this is cool as hell.

I've reading up about the architectures and programming of computers and consoles from the 80s and early 90s lately, and have been itching to do a similar project of my own, but have been kind of floundering on where to get started. The fact that you pulled this off inspires that this sorta thing can be done.

Have you considered doing a series of blog posts going into more detail on each section of the console and your journey in getting each bit working, describing failures and successes both? I think such would be instructional to other people who want to do some similar homebrew computer/console hacking.

I was kind of surprised that your PPU design was frame buffered instead of line buffered, but I suppose I perhaps shouldn't be. I imagine the PPU chips of old were line-buffered because RAM was expensive in the 80s, and it was a good enough interface to control a scanline-based display. In my recent reading about the architecture of 3rd, 4th, and 5th gen consoles, I noticed that the 5th gen systems became fully frame buffered, as memory had become cheap and fast enough in the early-mid 90s. And a frame buffer certainly feels a bit simpler and more intuitive to think with than a scanline buffer.

Thank you :)

I am considering doing a series of blog posts, I don't know how often I could write them or if I could keep them going, but I will try. I'm not big in social media and I have never written any posts or anything like before this one, which is weird, I'll admit it, so all this is kind of new, but I think I'll give it go.

Old systems used line-buffers like the Neo Geo or no buffers like the NES, for example. So yeah, going with a frame-buffered approach was definitely easier, but this was not the only reason I chose this way. I had a lot of restrictions, I was learning a lot of stuff, I didn't know how to work with FPGAs and I stuck with DIP package ICs that I could put on breadboards and experiment. And that's why I picked the AVR microcontrollers, which are awesome but have their disavantages. They have good performance (20Mhz), but not many pins and I had to bit-bang things like external RAM access (actually the PPU accesses 3 RAMs with only 32 IO pins available), which meant that it takes "some time" to access external memory. That's why I chose 2 microcontrollers for video instead of just one, one of them could take "all the time in the world" (one frame) to fetch information and write a frame to the frame buffer while the other would generate the video signal and dump the a frame to the TV. Connecting the two, I felt a double buffer was better.

I definitely would have preferred doing a more "traditional" non-buffered render system, but this was the solution I found with what I had to work with.

I hope serves as a good explanation and maybe I'll get to explain these details better in another post :).

I know this has been said before but this is one of the coolest things I've seen posted here on HN. My undergrad is in computer engineering and this post brought back a flood of writing VHDL and doing design in Mentor Graphics.

I'm going to read this a few more times. It's like reading a good book about my hopes and dreams.

Thanks :) (I don't mind people saying it over and over again, believe me :P)

I actually started building a much smaller video game console with a cheap Cyclone II FPGA board (a friend of mine wanted one and I tried to figure it out how I could make something smaller and cheaper but still retro and cool) and I'm using VHDL, it's not exactly easy to learn but it's pretty cool, and I find it really hard to find good resources to learn from.

If I was to start all over again, I would use an FPGA for the graphics, for sure, at the time I just didn't know how.

And thanks again for the comment :)

You could use a Zynq FPGA that has a built-in dual core ARM processor. It has 512K of L2 cache and 256K of memory, more than enough to basically copy the same architecture into that design. It also has ADCs built in so you can implement analog joysticks too. It's also probably fast enough to build a graphics processor in logic. Only thing you may want to keep is the sound processor because there is no built-in DAC so you would need to implement that anyway.

Port it to MiSTer?

This is a wonderful project. Well done. You might just inspire this software engineer to take his first crack at hardware. :)

One somewhat personal question, if you don't mind. You say you are Portuguese. Is English a second language for you? I don't see the telltale signs of a Portuguese -> English speaker (I have a lot of experience interacting with Portuguese speakers, and their English mistakes are pretty uniform due to the specific differences between the languages, esp regarding prepositions and tense). Your article, as many have noted, is beautifully written even for a native English speaker.

Thank you, if it's something you like, you should try a hardware project, for sure :)

And yes I am Portuguese, born and raised and I do know what you mean, there are mistakes that are somewhat common for Portuguese speaking English and I do make an effort not to make the same mistakes. However I know my English is far form perfect and it's always easier when it's in written form. I think that the fact that I've always spent too much time watching american/british movies and TV shows made me pay more attention to how English should be spoken :).

But anyway, thank you for saying I speak perfect English, it's actually a great compliment. :)

It's almost like Portuguese people are not a uniform block, right?

I can see how that remark could have felt bad, but there are plenty of opportunities not to take it that way. This is why we have a site guideline that asks all of us to "Please respond to the strongest plausible interpretation of what someone says, not a weaker one that's easier to criticize. Assume good faith."


Who said anything about Portuguese people as a uniform block? That doesn't even make any sense as it's not only Portuguese people that speak Portuguese lol. I only referenced those who have either chosen or were involuntarily exposed to English as a second language who speak Portuguese natively.

> and their English mistakes are pretty uniform due to the specific differences between the languages, esp regarding prepositions and tense

This is not the case. Different people make different mistakes, as any exposure to a high-school level English class will allow you to discover. There's a case for clusters of similar errors, but then again any generalizing statement is true for a sufficiently high level of clustering.

That's a very strange view. Of course people with a native language will make similar mistakes when learning a new language. Swedish speakers have issues pronouncing "jump" ("yump" ) and cheap ("sheep") because the language doesn't really have those sounds. Because were and was is the same word in Swedish, that's also a common mistake.

"Their" referring to the group of Portuguese speakers that I know, not Portuguese people as a block. That implication came about due to you alone. The observation that you quoted is based on both my interaction with them, but also their interpretation and observation of themselves relayed to me in conversation(many of them are in the field of linguistics, so this type of thing comes up a good bit).

I can see how you could draw that conclusion from my post, however. I assure you there was no intent to generalize.

> I assure you there was no intent to generalize.

My apologies for misunderstanding, then. And thanks for making that clear.

It's interesting how this kind of project has come into the realm of possibility of an individual's pet project (a smart individual, sure, but not a company).

I guess that the availability of information and materials through the internet has helped a lot. And also more people have knowledge in electronics and programming.

Great job, Sérgio. É muito giro.

I agree (and thanks for calling me a smart individual :) )

Nowadays is so much easier to get information on how to build something apparently very complex. You don't need to go to a library or seek out and go talk to experts, you actually have access to all that through the internet in forums, articles, posts and videos.

Also it's easy nowadays to order all the things you need for a project online.

Thanks :)

Also the access to a massive library of freely shared code libraries and examples. While working with arduino stuff its amazing how when I buy some random part off ebay I can find someone who has already spent a week writing a library that makes everything super easy to use. If I had to do it all myself this would take forever.

Interestingly enough, looking at the HW, there is not much there that wouldn't have been feasible for hobbyist a decade ago. But of course the community and information has absolutely exploded during that period

Interesting perspective. I wonder what kinds of projects a motivated individual would be able to tackle say, 20-30 years from now.

Perhaps building a world where the occupants don't realize they're in a simulation....

I reckon that with 3d printing and more components, people with little knowledge in electronics will be able to put together something useful.

You're a top notch hacker, from high to low level. Not many people can do what you do. I know this is a hobby/fun project, but I really hope your current employer/clients appreciate and reward you commensurately!

I never comment on here. This was cool enough for me to try to figure out my password and log in and say that you are the tinkerer/creator I wish I could be.

Thank you so much :)

I'm actually a bit overwhelmed with all the comments and I'm trying to answer at least a few of them.

Just wanted to say that, even without knowing you, I think you could absolutely be a tinkerer or creator, just choose something you would like to build, start small and go from there. :)

This is something I wish I'd be able to do one day, but every time I look into getting into electronics I get overwhelmed.

Can you recommend the materials you used when learning? Books or resources etc.

This was a really interesting read, thanks for sharing.

Thanks :)

Well nowadays there's a lot of material online, I did find a book interesting, though: "Make: Electronics", it teaches the basics in a very nice way.

Aside from that the key, I guess, is to start small and incrementally go for more and more complex stuff going towards things you like (video games, robotics, etc). If you consistently achieve small victories I think it's enough to stay motivated. Everytime I managed to overcome something, I took it as a victory (generating the video signal, getting a program to run on the CPU, etc) and this helped me get to the next problem to solve.

I started with discrete logic and an Arduino, went on to programming microncontrollers similar to the one on the Arduino and moved from there to CPUs, RAMs, FPGAs, etc.

Also Youtube channels like EEVblog and GreatScott! are great learning resources.

People invariable ask a form of this question every time an impressive project like this is posted.

For what its worth(1), I think that "learn a bunch of stuff -> go build something cool on the first try" isn't quite the right approach. I think you have to set for yourself a series of tasks and then fight like hell to figure out how to accomplish them. Start with a single blinking led. Just google "how to blink an led" and try to do it a few different ways.

In short the only "material" you might use to get started is google, by typing in "how do I..." while chasing modest goals that look like they might be in roughly the right direction. If there is a magic book out there that will "teach you electronics", I haven't found it yet. It sounds a lot like the sort of book that might "teach you astronauting".

"Electronics" is broad enough that it might be more like learning a language than learning a skill.

(1)My own meandering opinion

> For what its worth(1), I think that "learn a bunch of stuff -> go build something cool on the first try" isn't quite the right approach.

There might be also some kind of misconception in the way that you're seeing something cool and now also want to get this cool stuff. But if you aren't interested in the fundamentals - in this case electronics - and don't have fun learning these by simple experiments - like you described - then it's neither worthwhile for you nor you will get to the cool projects.

The first half of nand2tetris[1] (projects 1-6), which corresponds to their first Coursera course[2] is a great introduction to the digital side of electronics. The second half is more general purpose computer and OS specific but probably still pretty useful. I've only finished up to chapter 5 as of right now, so I can't say anything definite.

[1] https://www.nand2tetris.org/

[2] https://www.coursera.org/learn/build-a-computer

I quite enjoyed Ben Eater's playlist on building a breadboard computer, made a lot of electronic concepts click for me.


Start with an Arduino. Really simple circuits and you get to learn on a microcontroller. It's fun too. For instance learn how to turn on and off an LED then go from there


There's the xgamestation boards that you put together yourself, that give you a helping hand in the initial steps of building your own retro console: http://www.ic0nstrux.com/products/gaming-systems/game-consol...

Has anyone here actually built one of these? I've eyed this project for forever, but I've always been a bit reticent for whatever reason. I think I'm nervous that either things are sufficiently put-together before I get it that I won't learn, or that they won't have time to go into everything, so it'll just be a soldering-based LEGO.

I’m no expert whatsoever, but I’d recommend getting an Arduino (the cheap knockoffs aren’t horrible, but if you get one, be sure to donate a couple of dollars to the legit Arduino people), a couple of big breadboards, a jumper wiring kit (preferably with all of the different inch fractions so your wiring stays neat), and some basic components (resistors, capacitors, LEDs, buttons, simple ICs, etc).

Once you have all that, get the Arduino do turn on an LED when you press a button on the breadboard. Incorporate some kind of sensor, if you want. After that experience, you should be ready to tackle a bigger project. Now that you have a test bed, you can incrementally build circuits from books and the Internet and actually understand what’s going on.

Start small. Here's a shift register: http://www.ti.com/product/SN74LV8153

It turns serial signal into parallel output.

They are often found in kits like this: https://www.amazon.com/Smraza-Breadboard-Resistors-Mega2560-... (research a better one than this)

Get a Raspberry Pi (Any controller really, get what you what)

Build something useless like this: https://www.youtube.com/watch?v=Lgnopk1qmkk

There are lots of learning kits available on Amazon. That's how I "taught myself" hobby electronics. I don't know much, but this stuff is magic! So it's impressive to most just to implement a simple shift register! Blinkenlights for the win!

+1 from me. I am a lot interested in getting into hands on electronics and most of the times I end up falling a little too short as there is no support around where I live and I never really got a start. Would definitely love some inputs from people who are good at this.

It's dense but the Art of Electronics is the one book I keep coming back too. Better as a reference than a tutorial, once you've played around with an Arduino or the like I found it great to opening up the "what next?" part of EE.

Shine on, dude, shine on. Inspiring! I love the fact that you've been working on this for a long time, yet 60 seconds ago I was completely unaware of it. What other amazing things are amazing people working on out there?


It's like other people are real, or something.

Impossible, I am the hero and everyone else is an NPC. It’s just a very good algo.

NPC's to inspire you to start doing that thing you were thinking about.

This is simply incredible. I teach high school and elementary kids, and the thing I'm always telling them and parents is how the added complexity and modern design of software and hardware have made it so challenging for kids to take a "peak" under the hood. Projects like this are such a wonderful way to really spark that curiosity between hardware and software. So inspirational!

You see this with grown up devs too. Many of them have only ever learnt to code with a full suite of build tools such as web pack, grunt and npm. They seem lost without these things and only a few really know what's going on under the hood. The best devs I've worked with are feel comfortable getting things done even when those tools are taken away.

I know that I am echoing the same sentiment, but how cool is this! In the video where you demo'd BASIC and had that ball bounce across the screen, my jaw literally dropped, and my mouth stayed open the whole rest of the page. Amazing :)

This is incredibly impressive! You should be very proud of yourself for not only having the knowledge to work through a project like this but also the discipline to see it through to fruition. Hats off!

THIS kind of project is why I've replaced ./ with HN in my favorites bar. Thanks for sharing, this is an incredibly cool project!

In case you don't know about it, see also: https://hackaday.com/

It finally happened. I had to sign up for Hacker News just to give props. Very cool and inspiring project. Thanks so much for posting.

This is both amazing and terrifying.

Seeing all these breadboard cables going into a scart lead fills me with dread. One bump of the table and the chunky scart lead flexes in an unpredictable direction and rips out a subset of 4 hours of carefully set jumper cables. Not to mention the EM interference that so many wires must be generating.

This is very cool.

At risk of being more "me too" about this, I am in awe of the hard-earned multi-disciplinary skills that went into making this. You should be proud of yourself :) Great project, and a great read.

Thanks for the comment :)

I am proud and honestly reading all these comments of people like you saying awesome stuff and also saying this inspires them makes me even prouder :)

You should talk to the 8bits guy, he's on the process of creating his own dream 8 bits machine, and it looks like you've beaten him :)

I agree! I was just watching one of his videos the other day on creating a brand new 8-bit computer and I think he would be super interested in your work.


Retro gaming in general is about re-enacting the consumption of games, I have never though that you can also re-enact the development/production of them :) Good work!

This is super cool. Do you have plans to make the emulator public? If so I'd be very interested in developing software for the console.

This is so badass! Not only are you a good hacker, but your writing was a pleasure to read. I wish that I could upvote this more than once.

This is very cool. Doing this all on your own, especially since you're not a computer engineering professional, is astonishing.

The one thing that irks me about the console design is the amount of RAM it needs. In the age where 8-bit consoles were actually being built, RAM was the most expensive part of the devices by a far margin. It is no accident that the Atari 2600, for example, only had 256 bytes of main memory, and even the very popular NES/Famicom ran on only 2kB of main memory. This "retro" design, by contrast, employs a lot of RAM chips in a variety of places, even where they are not actually needed: the CPU and PPU can be connected with different technologies (as the article hints at), and double buffering via a second VRAM chip is the kind of feature that classical home consoles would never do due to cost reasons.

Don't get me wrong though, it's still an amazing project!

Yeah I did put more memory than the old school consoles had, absolutely, however the RAM in those days was only used for data mostly because they also had the cartridge ROM (or ROMs) to store the code. In my case I need to load the code to RAM, so I would always need a larger RAM.

But yeah, they also had less colors to work with and palettes (which were costier to implement in a software renderer). And this CPU is also faster than of those consoles. I did give myself a more confortable system in terms of RAM and computational power.

But my aim was for a machine that would sit somewhere between the 3rd and 4th generation.

The double buffering I understand as well, if I was working with an FPGA I would not have gone with frame buffers, for sure, but that was the solution I found at the time using the components I was using and it worked.

The attention this has gotten, especially here in HN is still a bit unbelievable to me (and amazing of course). I don't want people to think this is an optimal console design or anything. This is by no means a perfect project or "the way to go" in terms of homebrew video game consoles, it's just the way I found to do one while learning electronics along the way.

And thanks :)

If you're interested in this you might be interested in 8-bit Guy's new computer: https://www.youtube.com/watch?v=ayh0qebfD2g

Yeah, his project was the first thing that came to mind when I saw this.

Great project and kudos to you for seeing it through to completion. In our spare moments this is often the greatest challenge. I read the whole blog post, really cool to see the architecture diagram, would love to see more.

I would like to express my deep admiration and esteem for you. The tenacity, competence and intelligence that your project demonstrates is what this planet needs. You are a great hacker and you have all my admiration.

I'm surprised you didn't implement a simple 8k bank switching scheme to utilise the rest of the 128K chip, it's really just a handful of 74244 buffers and a 74138 decoder stuck on an IO port.

I thought about it, I really did, however, I really felt I didn't need the extra RAM, especially for the kinds of programs and games I was aiming for.

And in this case "a handful of 74244" is a lot more complexity and it got a to a point where I really wanted to minimize the amount of ICs I used.

Also I was felt bank switching added complexity when developing for it. This way I can write a C program have it access data and I don't have to worry about the code being split in more than one bank or having the data be in a different bank than the code, etc.

It's a nice catch though, thanks for the comment.

I was expecting to see an article about yet another retro pi but I’m seriously impressed by this. Not only is the hardware really cool but your tooling and software setup is equally impressive. Great job.

This is so awesome, a righteous hack built from chips up. Just what we need more of on a site called Hackernews.

Wow! I was impressed to start with, but then the article and the build kept going, and going, and going .....

This is a brilliant project. I've toyed around with electronics and microcontrollers and I once wanted to build a full "desktop" PC with an STM32 and a PS/2 keyboard input and a VGA output. Unfortunately, school took over me and I left it.

One thing that I am curious about though is whether you could use such a big project as yours for employment. E.g. if you had absolutely no formal qualifications and applied to a (relevant) company by using such projects in your CV, would they consider you?

First of all thanks :) And if you do find some time that project seems really cool, I never really got to work with the STM32 micros, but they are really powerful and cool.

Answering your question, well, even thought this is an electronics engineering project, I don't feel qualified to work with electronics professionally, for example, there's a lot of knowledge I lack. I do work as a software engineer and I have done a couple of interviews myself to hire people and I do believe this helps when applying to a job, I'm not saying it completely replaces your qualifications but it might at least give you an edge. I'm seeing this as someone who would want to hire someone skillful. A technical project certainly is on the very least a nice thing to have in a CV. Of course this is just my opinion. And if you are feeling like applying for a job based on your projects, just give it a go.

One advice I can give is: if you do have projects of your own, big or small, don't do it like me and keep them to yourself for years :P. I really had no idea so many people would appreciate my pet project.

Wow! What an achievement. Putting it all together, including the YM3438 FM chip, great work!

This is awesome. Congratulations. Have you considered turning this into a book, or a MOOC, or something you could sell? Many people would be interested.

This is awesome inspiring. All from discrete ICs and fully hand optimised. You could always make it into a kit and do a Kickstarter though.

Muito bom! I'm not sure I understood more than 10% of this but I love the concept and the determination to follow through on it.

Cool hack! I'd like more details about how you removed the wires (custom board or otherwise) or got the IC equivalents.

Ideally I'd like to see as few dangling wires when making something like this, because I have fat finger syndrome. :) I prefer joint wires with headers in them (like ATA cables) but that's just me.

Lemme hijack this opportunity to request someone to make the console I have always fantasized about, as a gamer and a developer:

• TL;DR: Basically an iPad with detachable controllers and open-source OS, SDK, app store and sideloading. OR: Basically a Switch with fewer OS limitations, sideloading and lower barriers to development and publishing.

• Nintendo Switch form factor.

• Capable of connecting to external displays and using wireless controllers, mice and keyboards.

• A semi-multitasking OS, where only one app has screen focus but you can have messaging etc. apps in the background, notification overlays and use a web browser at any time. (I'm mostly thinking of the dear old PS Vita here.)

• A single, centralized app store while still allowing users to run apps downloaded from anywhere else.

• An SDK that lets you write games in the language of your choice (but if we had to choose: Swift, please.)

Very impressive. My first thought is, why? Just use a Pi with Retro-pi. However, you wanted to be down at the metal. That's quite a challenge, particularly when you work alone.

I'm always impressed when someone is skilled at both hardware and software to make a finished product. It's Woz-like.

Very impressive work.

Because the journey is more important than the destination.

Yes the journey was very important, absolutely.

Also I had set myself a specific set of goals that obviously are not going to make sense to most people and I understand that.

It could seem like a daunting task at first, but breaking it into milestones actually makes it easier and makes the journey a lot better.

The same reason people run a marathon instead of just driving the route.

This is so far above my head that I really don't have anything to add to the discussion that hasn't been said by people who know a lot more about this stuff but I really just have to say this is insanely cool and inspiring.

This is so very cool. It really took me back to the late 70's when I was a kid and my dad built a "computer" that took up an entire 4'x6' workbench. We played lunar lander on it, but I never knew what we were doing because it was just a numerical LED display. It looked very similar. Just breadboards of modules connected by hundreds of wires. One day, my little brother was playing in the garage where the "computer" was, and discovered the wire cutters... 2 years of work gone in a few minutes. Yes, he's still alive. How, I don't really know lol. Epoxy that thing!


Incrível e inspirador! Thanks for sharing this and congratulations for this amazing accomplishment!

Very impressed and you come across as such a nice person too! All the best to you.

(I'm actually secretly a horrible person :P)

Thanks for the comment :)

This is something I have set out to begin (or similar) and ended up giving up on, multiple times. Maybe this will motivate me to finally pull something off!

This is awesome work, as someone else mentioned, I would totally buy the book.

Awesome work! Here’s a similar project (done using an fpga) I saw on github: https://fotino.me/consolite-fpga/

As someone who grew up using an Z80 powered MSX, this brings back a lot of memories.

It's amazing how "accessories" can make even an 8-bit processor go far

Projeto fixe demais!

If you made a kit and put it on Kickstarter I’d buy one. Just sayin’

I can't remember the video post, but something similar was here few years ago and the guy decided to make a video series for the project.

Can you do the same for a new project from start to finish?

This post makes the failure of micropayments poignant: if one-click payments were possible, its creator would be enjoying a unexpected inflow of cash. Real soon now, like cold fusion.

Just awesome!!!

I built a 68k machine (no video, just CPU, Serial I/O, RAM/ROM) in high school and it was really nostalgic to see your incredible and awesome project!

Congrats on such an awesome build!!!

This is outstanding work. You should feel proud that you created something this complex from scratch over a number of years and did not give up! I'm in awe

I'm myself a self taught electronic hobbyist who followed the same path you did I guess (eevblog and such). I'm nowhere that good at the moment and you sir are an inspiration to what can be achieved with dedication !

Thank you for making such a project and for putting it online for the world to see. Your friends were right ;)

If you haven't already you should definitely add your project to hackaday.io (the community driven part of hackaday).

Great work! I wondered what resource you have used when you started learning electronics. I'd be really appreciated if you share them

Like I wrote in another comment. There's a great book called "Make: Electronics". And you can get started with an Arduino kit, it comes with a book and several components. After this when you feel comfortable, you can move one to more advanced stuff, depending on what you're interested in.

There are plenty of videos online for almost any topic in electronics, and projects online using all kinds of components and for all kinds of purposes.

Check out EEVblog, the forums are good, and there are some videos for beginners and also the Youtube channel GreatScott!.

And thanks :)

Thank you for your reply!

I hope Woz sees this and says a word or three here.

Wozniak is a legend and this no where near the quality of his work. The way he designed the Apple II was just amazing.

Thanks for the comment :)

Nevertheless, I just emailed and tweeted him the link. You never know with Woz.... About 10 years ago, I posted a link about him on my blog. In it I wrote that he wasn't much of an athlete in HS. Within a couple hours he posted a comment correcting me, noting that he was a varsity pole vaulter on the Homestead High School track and field team. OMG

Thank you for sharing, this is a very cool project!

This is so freaking cool!!

I’ve been dreaming of building a Z80 computer for literally 20 years. I think you inspired me to stop dreaming and start doing.

I'm really impressed - what a great project!

I've considered trying a project like this in the past. You've given me a little inspiration to go do it! Great read!

Fantastic and really inspiring, with a great presentation and narrative to boot! I am impressed and a bit thrilled :)

Very cool project, I just wish the images on the website weren't many megabytes a piece. They can't even all load on my slow internet connection without timing out.

It's unfortunate how often people share files directly from their camera without first compressing and resizing them appropriately these days.

Thanks :)

And yeah you're right...my bad...

(EDIT) It should be a bit better now, thanks for the warning

"""Even though I had no experience, I said to myself “why not?”, bought a few books, a few electronics kits and started to learn what I felt I needed to learn. """

Would you mind sharing what books (and kits) you decided to buy? I'd like to work on my electronics a bit as well :)

Like I've said in a few other comments (I've been trying to answer some of the comments, everyone has been really nice and really interested), one book that got me started was "Make: Electronics", I believe there's a second one now, I really like how the book explains the very basics in a pratical way. Other than that there's a lot of info online nowadays. EEVblog aside from the forums has a nice youtube channel with videos with topics that range from beginner to advanced, GreatScott! is another one that explains things really well. Ben Eater has also a very interesting channel. Also check other people's projects similar to things you would like to make. As for kits, I started with the Arduino starter kit, it comes with a project book and a few varied components, after that I started buying components locally or from major international component shops and going towards the things that interested me the most in electronics. I hope this helps :).

I think this should give everyone the motivation to continue working on side projects till they are finished.

Wow. This is incredible. Bookmarked and will be a lot interested if you could do a series of blog post, man.

This is amazing.

Thanks :)

I'm gonna try and keep posting.

Congrats Sérgio! Such a cool project.

ok, this is the most awesome hacker news of the year so far. Really interesting, nice to see that you were able to make it work.

Sometimes I talk to people about some ideas and they say "too dificult, find a simpler project". Sending your post to these lazy devs.

Thanks for sharing. This looks awesome! Post likes this are the reason I follow Hacker News.

All those wires! You should checkout dirtypcb.com to get yourself a cheap pcb for your boards, that will make the it very special and longer lasting for you. Designing PCB with eagle on mac or kicad on linux are great software to design PCBs.

Nice job! Are you going to do more designs in the future? Maybe Verilog/VHDL based?

Thanks :)

Yeah, I already have another ongoing project based on a cheap FPGA board with a Cyclone II (quite old but it does the job), the idea is to keep it cheaper and much less complex.

The FPGA has a Z80 implementation, video, sound and handle the game controllers. An external Atmega328 is used to handle the SD Card and then just RAM, an ICs for composite video and an op-amp.

I also have some ideas for a better console, maybe a generation forward and an 8-bit computer, but...these are just ideas, I doubt I'll actually get around to do them.

I also made a Cyclone II FPGA implementation :] It looked like this and supported very primitive line rendering:

https://github.com/niedzielski/swankmania/blob/master/DSC057... https://github.com/niedzielski/swankmania/blob/master/DSC057... https://github.com/niedzielski/swankmania/blob/master/DSC057...

Unfortunately, the physical hardware and later the code were both stolen in separate incidents. I was able to recover some version of the latter I had shared with a peer. It's posted in the same repo but probably not worth reviewing as it's from my college days and a total mess.

It looks awesome, congrats :)

I'm sorry the hardware and code were stolen.

And of course it's always worth reviewing, I got inspiration out of projects just like that and besides my code is a mess too, don't worry about that.

Have you seen Project IceStorm? I don't know if ICE40 FPGAs would be good fit here, but they could definitely be more hobbyist friendly.


I've found it pretty easy to use the IceStorm toolchain. You can do everything from the command line without a funky proprietary IDE.

This is incredibly cool... I've thought about playing with some of the software emulators, but wouldn't have even thought to tinker with replicating or creating with real hardware.

similar project from december (using an oscilloscope)


Wow is that like creating a separate shell for running the games.

Amazing work :) It's very passionating to read also.

This is incredible! Thank you for posting and outlining all your work! As a fellow 80s/90s kid, this is extremely my shit.

Follow-up — you’ve inspired a colleague and I to do something similar! I read this, iMessaged her the link and said “we have to do this” (she has significant hardware experience. I do not.) and she’s in total agreement!

So thank you again b/c this is legit inspiring and exciting!

This is such a clool project.

I would be really curious for:

A porting guide

An fpga tutorial

This is absolutely amazing, well done!

Great achievement! Muito bom!

Obrigado :)

amazing indeed, what a great read, and inspiration to go build something...

Now pour coffee over the console!

(surprised by the lack of Bandersnatch jokes)

Great job on this!

dude, this is not a human, not belong to our universe, sollute

You sir, are awesome.

One word, awesome.

This is fantastic


beautiful project.

how does one obtain a z80 if it's not manufactured anymore?

Thanks :)

Actually they are still being manufactured to this day, that's one thing I didn't mention in the blog post is that you can get a brand new Zilog Z80 today, the 6502 (the CMOS version, 65C02) is also available. You can probably get them from all the major electronic components stores (Digikey, Mouser, etc).

Oh wow! This is so cool!

Awesome work. Parabens


Way more impressive than various fantasy consoles that typically involve a lua programming environment and an artificially limited screen. Here the limitations actually stem from the hardware being used. This is something that only huge companies could attempt to design not that long ago.

I once made a virtual machine for a console designed from scratch as "fantasy hardware", with its own architecture, assembly language, CPU, and so on. I'd like to be able to bring it to life some day as you have.

I love these posts of new retro consoles. I would love to see one that maintains the audio-visual aesthetics i.e. FM chip tunes, sprite-based 2D graphics yet otherwise pushes the hardware to the absolute max of what is possible today. I think the zenith of 2D gaming was consoles like Neo-Geo and Sega Saturn (and possibly a 2D arcade board whose name escapes me?) and I'm thinking of something along those lines. Does such a thing exist?

It's not really "retro" if you've been building it in $current-year.


Retro doesn't mean "old." It is a style.

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