How were 70s versions of games like Pong built without a programmable computer? | Hacker News Reader

How were 70s versions of games like Pong built without a programmable computer?

retrocomputing.stackexchange.com

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There's a scene in "That 70's Show" where Kelso and Red bond over Pong and decide to mod the game to make it harder. And a few hours later with a soldering iron, smaller paddles!

The first time I saw that episode was at a friend's house. I felt so smart telling him that was impossible because you can't mod software with a soldering iron. Then his dad poked his head out from the kitchen and told me Pong didn't have software.

Turns out the only impossible part of that episode is the idea of it taking a few hours. Changing the paddle size was a mod already supported by the hardware and the manual gave details on how to do it. Though it wasn't necessarily intended as a difficulty setting, it was intended to support different sizes of TVs. iirc, all you need to do is solder 1 jumper.

Kind of amazed Kelso disassembled something and it worked after (I think was the surprising part) lol

That’s probably what Red was there for. To lend a foot every time Kelso needed it.

There was a downplayed running joke where Kelso was actually extremely skilled at engineering. In another episode, he repairs a car with Red and explains what he’s doing in high technical detail while Red just pretends to know what he’s talking about because he doesn’t want to admit that Kelso is smarter than him at something.

Idk. A few hours for Kelso to solder a jumper sounds about right.

I had no idea that scene was somewhat accurate! I just watched it and had the same feelings you did.

>I felt so smart telling him that was impossible because you can't mod software with a soldering iron.

Many old systems stored their software in a diode matrix, which could be modded with a soldering iron: https://www.cca.org/blog/20120222-Diode-Matrix.shtml

Well damn that's neat. I'm going to pretend you were popping your head out from the kitchen as you wrote this.

Also note that Dave's https://CCA.org deserves perusal.

My favorite page remains the one about his computer:

https://cca.org/dave/tech/machine.html

Awesome! I wonder what his electric bill is like.

I imagine this is how some sci-fi technology works. Certainly looks like a more low-tech version of some of it: Star Trek has both isolinear chips [0] in Federation technology and isolinear rods [1] in Cardassian technology that can be rearranged to change ship systems and Stargate has control crystals of various designs used similarly [2][3][4].

[0] https://memory-alpha.fandom.com/wiki/The_Naked_Now_(episode)...

[1] https://memory-alpha.fandom.com/wiki/Isolinear_rod?file=Isol...

[2] https://stargate.fandom.com/wiki/Control_crystal?file=Contro...

[3] https://stargate.fandom.com/wiki/Control_crystal?file=Door_c...

[4] https://stargate.fandom.com/wiki/Control_crystal?file=Contro...

Mind blowing; both ways I guess. I’d like a tv show where someone building this gets to interview a time traveller from the 2020s and the latter knows nothing useful about hardware but can provide many unhelpful details about having GBs of storage, or things like DRM, pentalobe screws or electron framework.

Here you go - https://pastebin.com/raw/dGP6W1m1 (story courtesy ChatGPT). Fed your comment into it, and got this story.

I’m pretty sure the GP was thinking of something having qualities such as "funny", "well-written", or "creative".

This is like the least helpful or useful kind of comment ever. Hey I got barfed on by an LLM wanna see?

I remember that!

I think I had thought it was possible. But in my mind there was no way Red or Kelso could possibly know how to do it.

The fact it was in the manual helps make that more possible. Don’t think the episode showed/implied that though.

Yeah in the episode they are definitely doing things that are not indicated in the manual. Makes for a much funnier bit though.

Haha, I felt so smart telling... that's HN in a nutshell!

Bold of you to assume it wouldn’t take me hours to solder one jumper!

> Changing the paddle size was a mod already supported by the hardware and the manual gave details on how to do it.

Amazing, that a manual would discuss resoldering a jumper. Today's manuals warn you not to open the case and not to eat the batteries.

I’m old enough to remember when there were some devices with schematics included inside or when you could order a complete service manual from parts vendors. Nowadays I’m happy to find replacement parts and if there’s no code inside them.

That's a great scene. I mostly remember it for the exchange the two had after they finished modding the game and it worked [0]:

Red: "Congratulations, son! You have seen the future!"

Kelso: "Yeah, yeah, you're so right, Red! Home computers! That is the future!"

Red: "No, no, no. Not computers! Soldering! The future is soldering! [...]"

How often do we try to extrapolate from current technological improvements to predict the future, yet fail to grasp which changes are truly important.

[0] https://tvshowtranscripts.ourboard.org/viewtopic.php?f=936&t...

About 25 years ago! I was helping a friend/client look for something in his basement store room. He pulled out a huge multi-page schematic and said "look at this." It turned out to be the controller for a medical device he had designed in the early 70's. All discrete logic, no CPU at all. Blew my mind.

As a Computer Science graduate without an Electrical Engineering background, I was trying to wrap my head around how that was even possible.

I wish more CS curricula would start with digital logic and stay there for a little longer before going into the full stored-program computer. That used to be the norm.

One of the first Pong ICs, the AY-3-8500, is reverse-engineered in this series of articles: https://nerdstuffbycole.blogspot.com/2018/01/reverse-enginee...

Indeed, back in the 90's our software engineering degree had lots of shared lectures with electrical engineering.

Digital logic would go all the way from boolean logic to designing our own toy CPU, with implementation using discrete logic components left as optional for those that felt like going for the top score on the assignment.

Additionally we also had stuff like EEPROM programming as optional selection for the total credits.

Interestingly enough, stuff like Prolog and LP, was also a required lecture for both engineering degrees.

In Sweden, rather than a "computer science", there's a "computer engineering" degree that also retains a lot of the electrical engineering stuff such as building a computer starting with a diode, building a flip-flop, a shift register, etc etc. Karnaugh Maps and everything.

I always have problems after all these years understanding US concept of CS being mostly theory, because in Portugal that isn't something we have as such, that is rather a specialisation of Maths degree (Maths applied to Computation, loosely translated), which only math nerds take, not those into computing.

Even if we translate our degree names to CS, the contents of those 3 to 5 years are very much hands on, with many lectures requiring successful delivery of project assignments before attending respective exams.

We have both options in the UK, CE is what I studied.

Computer engineering degrees are also a thing in the US. I used to joke with friends it was 2/3rds Computer Science and 2/3rds EE.

https://catalog.utdallas.edu/2024/undergraduate/programs/ecs...

It's no joke - my Computer Engineering degree overseas was literally that. The average completion time was 6 years, I speed ran it and completed in 5 1/2. Nobody AFAIK could ever do it in less than 5.

Nobody did it in 6 either… we all changed after first year into with comp sci or the arts

In Portugal, before Bologna changes, a degree would take 5 years by law, but on average would be around 7.

After Bologna, no one really takes the plain three years version, as the old degree was upgraded to include Msc, and everyone with the old degree also got equivalence to the new one with Msc, and no one wants to search for a job having only the lowest level degree.

We had a course like that and I absolutely loved it. It's the most fun I've ever had in an educational setting.

It followed such a lovely flow, starting with the absolute lowest level of computing (binary maths, diodes, transistors, and building logic gates with these) and kept on combining these building blocks until we arrived at modern computers and software.

Even if you're just a "modern age" developer that only ever uses modern programming languages, just understanding how everything is built makes you make better decisions all around.

Any books/courses like that out in the open?

Go through the Ben Eater channel on YouTube. It'll get you up to speed with early 80s computing. Computers quickly stop feeling like magic after you grasp the basics. Watching him build a VGA card should be enough to intuit how Pong was made.

One which gets mentioned often is NAND 2 Tetris, which starts with basic logic gates and progresses to produce a simple computer:

https://www.nand2tetris.org/

Also try nandgame.com

https://www.nand2tetris.org/ starts making logic gates until you build a language in assembly, which you implement Tetris with.

Pong doesn't have an ALU. The image and scoring emerge directly a forest of logic gates - mostly by timers and counters that scan the display, read the input controllers, and trigger logic events at various points in the scan cycle.

Memory used to be ridiculously expensive, and it was cheaper to build a board full of dedicated logic than a simple CPU with a full-screen frame buffer.

That’s crazy when you read it like that in 2024!

Why start there?

I get that there's a timeline, and that following the timeline is a good way of building a base but...

But... you could also add it to the middle or end of a course. I feel students would be more likely to appreciate the material. Would also be good to have "easy" courses that aren't fluff.

> I wish more CS curricula would start with digital logic and stay there for a little longer before going into the full stored-program computer. That used to be the norm.

I remember sneaking[1] into a few of those courses during university. Loved them.

The problem is that most computer science students viewed them as useless. They wanted to take, what they thought of as, useful courses. If it wasn't C++, it wasn't useful. Even the computer science students who were interested in pure math, these were computer science courses after all and the university offered a separate software engineering degree, didn't see them as useful.

A slight tangent: one of the courses I had the most fun wasn't even a computer science course. It was a philosophy course that spent a lot of time on computability. Cramming a bunch of genuinely interested social sciences students into the same room as a bunch of genuinely interested computer science students made for an absolutely amazing course. In contrast, the computer science department version of the course was populated by a majority of students who were only interested in the mandatory credit. It made for an astoundingly terrible course.

(These thoughts are from the perspective of a mid-1990's physics graduate.)

[1] Sneaking may not be the right term here. People in the department knew that I was doing this, to the point where I managed to get access to department computers and even managed to take a course for credit, with special permission from the professor and without the prerequisites, but the administration certainly didn't know about it since I didn't even bother with the official "auditing a course" route.

This right here is what a university is for, and why it's useful to cram a bunch of people with widely-varied specialities into a shared physical location. It's about exploration of knowledge through cross-polination of ideas. Social science and computer science students in those classes learned things from each other that they wouldn't have otherwise.

We see over and over again through history (Renaissance Italy, Bell Labs, Romantic-period Berlin, early-Google's cafeterias) how cross-disciplinary conversation inspires innovation.

The "useful" classes are necessary, but if institutions (or students) stop there then they have missed the whole point. They're treating class-work as office-work, and making that the summit of their ambition.

You're certainly correct about learning from each other, but I think it went beyond the cross-pollination of ideas. I took several higher level courses in other departments that were intended for majors in the other department, yet attracted students from across the university. They were always more lively than the homogeneous courses, introductory courses, and "bird courses".

I am bringing that up because a lot of universities mandate interdisciplinary courses, yet sabotage their value by letting students limit themselves to introductory courses or even offer special courses directed towards non-majors. Students frequently attend those courses for an easy A, but never let their preconceptions be challenged or bothered to challenge the ideas of others.

(That said, I don't really blame students for treating universities as vocational schools. I'm pretty sure the ones who went straight for the grades found more success in their professional life simply because they didn't let intellectual curiosity interfere with their professional goals.)

I agree with all of that. I acquired a reputation at my (very small - maybe it only works there?) college for showing up for classes for which I wasn't (on paper) qualified, and sweet-talking professors into letting me attend (sometimes for credit, sometimes not. Some of those were among my best experiences, too.

I gestured at it, but didn't quite complete the thought, in my first comment: a cross-disciplinary culture is essential between professors and departments, not just students. If universities are to be engines of innovation, and not glorified job-training centers, then experts have to form social bonds, and have out-of-band conversations, and develop projects together, too.

"Didn't let intellectual curiosity interfere with their professional goals" is spot-on as an indictment of our entire culture, at the moment.

We've had a whole generation now of CS majors who don't really understand the underlying hardware and it shows.

We’ve had three decades of computers whose inner workings are shrouded in secrecy. So I’m not sure CS programs are entirely to blame.

Yeah, other than students who get interested in all the hardware stuff (for whom there would likely be dedicated courses), I don't see how general EE courses help computer science study or career. If anyone really needs that later in the career, it won't be hard to pick it up.

That’s not what I meant at all, but then this involves a general conflict between a university and a vocational school (the second should aim to be useful even at the expense of comprehensiveness; the first comprehensive even at the expense of usefulness), or a CS and an SE degree.

I’m just wondering… did none of your universities offer Computer Engineering? I did it for one year before switching to CS because I just couldn’t grok how a bloody OpAmp worked back then and didn’t want to spend the next 50 years doing that lol.

My CE course was essentially an Electrical Engineering course with power distribution subjects replaced with programming subjects

PCs of the 90s were pretty open. Mid-2000s and then the rise of locked-down mobile devices was when it started closing up.

I mean there's only so much time in the day. The world of software alone is already so vast. It's literally a full-time job.

The fundamentals don't change. Computers still essentially work the same way. All of these languages eventually end up as machine code at the end of the day.

Dude those were different times. I remember building half adders and full adders with nand gates. Computing poles and residues by hand for 2nd order butterworth filter. There was so much depth to that!

of course nowadays i do the dumb shit everyone else is doing. import numpy as np, np.ones(arr), on and on. i once came across really convoluted business logic. rewrote that as a giant boolean expression and then simplified it using k maps. but when i tried to explain that in the kt session, they were like - what is k map ? what does that mean ? i thought wow i can explain it nicely and win the day. After all, in the kingdom of the blind, one eyed man is king. Instead, when i gave many examples and asked if they had any questions, they were like - what if a truck hits you on your way home ? then who will do this k map minimizing for us ? that’s when I suddenly recalled what actually happened in country of the blind. Nunez doesn’t become King. Instead, the blind fuckers chase Nunez to poke his eyes out. so in order to survive on the H1B, i had to forget all about the k map. pretend i am also blind and continue importing that numpy. otherwise i can forget about putting food on table.

I got my undergrad degree over 30 years ago and I was EE, not CS but I remember the CS students had an analog computing lab in addition to the digital logic lab. Even back then I remember thinking it seemed like a waste of time :-)

What you're asking for is already part of most CS programmes in Germany.

This site has a simulation of the hardware logic used to build Pong: https://www.falstad.com/pong/ball.html

Notably that is Atari's clone/rip-off. Magnavox's Table Tennis used diodes and transistors and was technically purely analog.

And of course Tennis For Two was also purely analog pre-dating ICs completely.

Yes, and it links to:

http://www1.cs.columbia.edu/~sedwards/papers/edwards2012reco...

Unrelated but important. Whatever you do if you end up in Berlin for whatever reason.

Go to the computer spiele museum https://www.computerspielemuseum.de/

Looks awesome, now I have another reason to visit Berlin.

If you're ever in the area of Milton Keynes in the UK, TNMOC at Bletchley Park is awesome.

https://www.tnmoc.org

I once wrote about this on the example of Computer Space (1971) — the very first coin-op video game and also the first one using this technology — and how this relates to the Atari VCS / 2600 and its TIA chip.

https://www.masswerk.at/rc2017/04/02.html#basics

A big similar discussion two years ago https://news.ycombinator.com/item?id=31511719

I watched this video on Youtube a few months ago that's very insightful!

It's about an arcade game from the 70's called Sega JET ROCKET:

https://www.youtube.com/watch?v=D0qlfEuzj6U

NTSC composite video isn't all that hard, you have voltages for VSync, HSync, VBlank, HBlank, Black and White. Generate the correct voltages at the correct times and you have a TV picture.

But TVs then didn't have composite video inputs, so you also needed an RF modulator.

I haven't heard these terms in years. My college Digital Design had a project to create pong and output to a VGA monitor.

Don't forget you need a balun to convert the RF from the coax output to the parallel-pair antenna input. Of course, the antenna input was already in use by the rabbit ears so you have to double up.

A very nice book is "Designing Video Game Hardware in Verilog" by Steven Hugg and is part of a series of books that is supported by

http://8bitworkshop.com/

I am writing a book somewhat similar to this (currently in Portuguese, but later in English and other languages) using the Digital simulator in Java for the examples as schematics, though they can be exported as Verilog for implementation in FPGA boards.

https://github.com/jeceljr/LivroComputadoresEVideogames

Each chapter represents a video-game console generation, with hardwired Pong and Soccer in the first chapter. I am now working on replacing the game logic in Soccer with a 16 bit version of RISC-V for the second chapter and then improving the video and sound to Colecovision levels. In chapter 3 we will have a 32 bit RISC-V with NES level graphics and sound, with a pipelined RISC-V with something like the Gameduino for chapter 4. The 8 Bit Workshop will let readers program the actual consoles from each era and not just our retro designs.

Apparently Dave Nutting https://www.youtube.com/watch?v=UzkGNL2AxP0 's reimplementation of Taito's 1975 Western Gun/Gun Fight for Midway was the first arcade video game to use a microprocessor, though I don't know if the original implementation was as 'hard-wired' as Pong or if it had evolved more towards being a full computer in TTL. https://en.wikipedia.org/wiki/Gun_Fight

Simmilarly, when the IBM 1401 https://www.ibm.com/history/1401 launched in 1959 it replaced large numbers of plugboard-based tabulating systems http://www.columbia.edu/cu/computinghistory/plugboard.html in offices.

Blip is a digital game, because you use your fingers to play it, and it used that cool BYTE Magazine computer font.

BLIP video game by Tomy commercial 1979:

https://www.youtube.com/watch?v=lPA7SQbwDOQ

Blip - 1977 Mechanical Pong:

https://www.youtube.com/watch?v=BSvZbcwqlTw

Basically by doing in hardware the same kind of logic decisions as we do in software.

Naturally this doesn't scale beyond basic games, due to the hardware requirements.

I have somewhere on my parents home a book from the 70's, from my father, dedicated to this kind of games, the precursor of BASIC games books from the 80's.

If you want to experiment this today, there are companies that sell such kits still,

https://www.ic0nstrux.com/products/gaming-systems/game-conso...

Thinking about what you wrote… an llvm2electronics compiler would be cool -compile source down to analog electronics!!

This is called "HLS" (high-level synthesis) and exists. The emitted RTL is atrocious.

Anything but the simplest programs will require way too much logic to implement with discrete components.

A friend's Dad has Wozniak's old VCR. We used to watch movies on that all the time as kids. Interestingly this person was also working on Pong, specifically on the ball device that used to move the paddle around.

some early video games were from Commodore; they had a box that generated a TV signal.. the box had knobs or perhaps a joystick. The games played by assigning a TV channel on the box, then changing the TV channel (with a knob on the TV) to that channel. The video game is now playing.

If you still have access to an analog tuner, you can do this trick with the ESP8266!

https://news.ycombinator.com/item?id=41740978

Even in the days of Super Nintendo we had the option of hooking it up the TV like this.

This was common on every console through the 2000s, composite cables were not the norm in my experience.

While the PlayStation 2 shipped with composite cables, even it had a coaxial adapter available for tuning to channel 2 or 3.

The original PlayStation didn’t come with an RF modulator. Neither did the Xbox or the N64.

The Super Nintendo was the last console I remember having one. The Genesis must have too.

But by 95 (PS in US) there were no longer the default. They may have still been available, I don’t know. Kind of doubt it but maybe I just didn’t notice.

I think it depends on market, at least some European / PAL PlayStations did come with an RF modulator[1]. The Dreamcast also did (UK at least), but that was an outlier, other consoles of that generation had RCA composite cables and an RCA to SCART adaptor.

You (nearly) always had to buy the RGB SCART cable you actually wanted for a good picture separately.

[1] random eBay listing, with RFU Adaptor pictured / listed in contents: https://www.ebay.co.uk/itm/364907339156 (Note Europe uses Belling-Lee connectors for TV antennas, so the connector is probably different to North American style RF boxes).

I don't know about other regions, but in the US console-specific RF adapters were available separately up to the Dreamcast/PS2/GameCube/Xbox generation, i.e. until HD over HDMI became the prevailing standard (Wii notwithstanding).

For the RF switch part, Nintendo actually recycled the NES design for all of them. It's kind of funny seeing that chunky gray box next to a GameCube logo.

I definitely bought an RF adapter for the N64 to be able to plug it into my old crusty TV at the time. But indeed, it was something you deliberately had to buy at that point and composite inputs were the norm.

Olimex just released a 1 euro game ‘computer’ based around a tiny RISC-V microcontroller. It drives a monochrome VGA display by bit-banging a couple of GPIO lines in software. Obviously the use of a microcontroller is cheating a little, but likely makes the system cheaper than anything which could be built with discrete logic or FPGA.

https://www.olimex.com/Products/Retro-Computers/RVPC/open-so...

"Original Pong did not have any code or even a microprocessor" : https://news.ycombinator.com/item?id=31511719

VM's just provide the software version of asic boolean logic

------------------

a) Boolian logic / explicit constructions to generate results. aka pong on specific purpose computation device.

b) Programmable computing / general purpose computer uses constructive logic (process of construction of mathematical objects aka programming languages)

c) "compiling"/"interpreting" b sets up the path through a to generate 'results' vs. a's fixed path/hard wired path transition/state table aka compiler generated type punning![0]

-----

[0] : https://en.wikipedia.org/wiki/Type_punning

    : punning with character : gawk chapter "11.3.11 And Now for Something Completely Different" program 

    : nil-punning : https://ericnormand.me/article/nil-punning

Pong isn’t that complicated. If you go even further back it gets even simpler. There’s a good example here: https://www.eevblog.com/forum/projects/oscilloscope-pong-for...

It looks complicated but it’s really not if you break it down into small bits and think of it like you would with a piece of software I.e. abstractions.

Did you RTFA?

It covers some things that are rather counterintuitive, especially if you come from a modern programming background.

Now is it complicated? No not really, I read the answer and immediately understood what was going on.

But no modern programmer would ever come up with the solution of addressing x and y positions by setting timers to wake at the times when the point in the scan-line or the scan-line in the frame was reached (although sleep-sort does exist).

If anything, the point of the post is the fact that it's very easy to understand, despite how counterintuitive it may be.

>>Pong isn’t that complicated.

>Now is it complicated? No not really, I read the answer and immediately understood what was going on.

Seems like you agree? Not sure why you asked if the parent poster RTFA.

> If anything, the point of the post is the fact that it's very easy to understand, despite how counterintuitive it may be.

Much like he seemed to have missed the point of the post, you seem to have missed my point about him seeming to miss the point of the post.

As a side note: I find the usage of RTFA and TFA pretty impolite and don’t like to see it on HN a lot.

Many come here just for the comment section and the discussions, not the article per se.

Thanks for calling it out, I feel the same.

If you're generating a PAL/NTSC/composite signal it's pretty intuitive to think of lighting up point X as turning on the signal (and this the electron gun) at a specific time because that's the way the "protocol" works. There's only one "wire" and the data is purely serial and synchronized to a specific scan speed.

This is also how the video hardware on CPU based consoles and home computers worked. They had counters and used them to either index into a frame buffer or look up hardware sprites, or both. Some machines did it more or less entirely in software (e.g. the ZX-80).

http://blog.tynemouthsoftware.co.uk/2023/10/how-the-zx80-gen...

Of course there are modern programmers who still do this today, bit-banging VGA on little microcontrollers and the like.

Ehm, now I feel really old. I just did a comment about this in some other thread. It's one of those timing things where it is hard to use a debugger. The scanlines scan in whatever frequency they are set to. You can influence the frequency and what color it should hit but you don't have exact control of the speed and have to set a timer or interrupt to fire when the electron beam is on the location you want to paint red. There are many programmers still alive that knows how this stuff works and now I feel like a dinosaur. :-)

How do you debug it?

I'm guessing you'd need to solder on your debugging tools (oscilloscopes?) in parallel, since anything else would completely invalidate anything that you were trying to do.

It honestly sounds like a recipe for Heisenbugs.

> But no modern programmer would ever come up with the solution of addressing x and y positions by setting timers to wake at the times when the point in the scan-line or the scan-line in the frame was reached

I would say it’s only fairly recently we stopped needing to do this - when we moved to graphics mode operation systems (oh god I say fairly recently but thinking now it’s probably close to 30 years ago yikes). I’m thinking Garmin app developer may still need to do it

If you want to learn more about this, I strongly recommend reading the 1978 book "How to Design and Build Your Own Custom TV Games": https://forums.arcade-museum.com/threads/how-to-design-and-b...

IMO you can only be confused by this if you think computers are magic. They aren't magic! Build your own computer on a breadboard! I did this and it finally got rid of the last bit of magic in computers for me. Now I can appreciate the beauty fully.

https://eater.net/8bit

Sometimes we do overuse programmable devices, where simpler logic would be even better (read no corrupted memory, instant boot, etc.).

One beat tool are the shift registers -- https://bobek.cz/traffic-light/

Cortex M0 chips are 10 cents and boot instantly.

I've seen a schematic of a Pong like game made with digital circuits like counters and comparators.

Each player has a Y position controller. So and Y1 and Y2 register. Then the ball has an x and y position. The game logic is controller by comparators to detect events like reaching borders or within the paddle width range. So for example if you reach the left border and is within left paddle range then bounce the ball back right otherwise the left player loses.

In terms of drawing to the screen, again compare the screen pixel position to each of the two paddles and ball position. Drawing the score was a little more complex but your have a counter for each players score and that determines which lines to draw. So you OR together the output from many comparator logic to determine the pixel should be lit or not.

One additional obstacle for modern audiences is that the TV sets themselves are computers running software. They take a MPEG-2 or MPEG-4 file coming in some network port and send it to some mixed parallel/serial interface to a LCD or similar panel.

If you understood how a 1970s TV worked (specially the simpler black and white ones used in the first video-games) then imagining a circuit that would generate the needed signals was a bit easier.

How were pinball machines built without a programmable computer? https://www.youtube.com/watch?v=ue-1JoJQaEg I think the arcade industry was already comfortable dealing with complexity to make the mechanical games. The Rube Goldberg nature of the early video games probably weren't that much of a jump in effort/engineering.

It is more like a pinball machine than a video game.

Now that I think of it it is really a rather unexplored field. Much more should be possible.

Imagine a car printed in the center of some transparent foil then you rotate the foil to turn. For the background you could have a giant map by projecting a tiny part of a rolled up slide. You could put the road logic on a large drum or hurdy-gurdy punch card roles.

Lots of possibilities.

This is exactly what EM (electro-mechanical) arcade games were, which were eventually replaced by video games. There were driving games, flight simulators of sorts, bombing missions, shooters, etc. Some of the earlier video games were directly copying/recreating earlier EM games. Video games eventually won, because they were lower maintenance. Also, video games allowed for what was hardly possible with EM technology, namely player to player competition, like in Pong. (This was probably the true revolution of video games: a competitive game, where players could match on equal ground, regardless of age, sex, size, physical strength, etc.)

Searching for "EM arcade game" on a video platform like YouTube may be worth it…

That really seems to draw on how radars are engineered. Is there any historical connection with defense contracting and Atari?

Have a look at Tiny Tapeout which is running a demoscene competition - essentially building hardware just like this (making hardware counting scan lines and pixels to make VCA)

We used to mess around with making video output from hardware in electronics class… it’s definitely old school cool in my mind

You can build logic circuitry with pure hardware circuitry is the simple answer, you don’t need a cpu.

Fascinating thread, thanks.

Somehow related pinball machines were way more complex than I'd ever imagine.

Technology Connections on yt has a great series on dissecting a nice electromecanic model, highly recommended

Truly a precursor to games like pong. It's just that relays turned into transistors and so we're able to operate at speeds that made manipulation of a TV signal possible.

On paper. I remember my cousin who is 50 now writing me letters, handwritten with entire programs in it. All i had to do was writing it and compile it. It often worked out of the box and was never longer than a few pages. I dont know how he did it.

That's not the question. There was essentially no computer at all in those videogames

You still use paper. Instead of writing the game in a general purpose programming language you write it using logic gates. You get abstraction and modularity by designing larger components (adders, flip-flops, timers, shift registers) on separate pieces of paper and then including them as named black boxes in a higher-level diagram.

The good news for the Pong developers is that most of those larger components were already available off-the-shelf. Common families of these chips, such as the venerable 4000-series and 7400-series logic families, began to appear on the market in the mid-1960's.

Edit just to add another bit of nuance. If it still seems like an extremely difficult task without much precedent, I think the lineage of these early arcade games can be traced back through their older arcade siblings: pinball machines. People had been building more and more sophisticated pinball machines over the decades since their inception in the early 1930s. For a look into pinball machines, some of their history, and an amazingly deep dive into the workings of a 1970's model, check out Alec's pinball series on Technology Connections [1].

[1] https://www.youtube.com/watch?v=ue-1JoJQaEg&list=PLv0jwu7G_D...

Wouldn't it be closer to say that the game was the computer?

A very simplistic and non-general purpose computer, but a computer nonetheless?

I believe this is correct, yes. It's not programmable but the term "programmable computer" exists because not all computers are programmable.

Bit heavy on the academic theory, but Claude Shannon's "Mathematical Theory of Communications" might help with the link between gated logic and modern computation.

CS builds/extends hardware based on Shannon's work. CS programming languages are classified according to the Cholmsky hierarch in theory of computation. Given topic of discussion, atari games implimented as logic gates are a form of state machine (autonoma) which can be represented at a higher level of abstraction by a programming language. ( https://www.geeksforgeeks.org/chomsky-hierarchy-in-theory-of...)

There are different frameworks / ways of implimenting/presenting 'logical computations'. aka ME physical, EE logic gates, math numerical computation, computer science programming languages.

Loosely ordered by various implied collision/response (XOR) for anaylzing/presenting "logic/type groupings" in physical spaces / virtual spaces.

Higher level/virtual logic/techniques of modern CS hids the 'logic bits' of things. aka gawk chapter "11.3.11 And Now for Something Completely Different" program -- where character fonts are higher order of logical groupings tied to a number of bits ( https://www.gnu.org/software/gawk/manual/gawk.pdf ) and pdf imaging ( https://github.com/tavinus/pdfScale )

Historical progression of display mechanics has less virtual abstraction relative to how programming languages produce/compute results.

No player movement, all autonoma state machine : https://www.youtube.com/watch?v=wiYTxjJjfxs

Progressing from "larger" implimentation to smaller implimentation details for equivalent amount of "logic states":

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A) mechanical logic devices and circuits : https://www.nacomm09.ammindia.org/NaCoMM-2009/nacomm09_final...

   zoetropes            : https://letstalkscience.ca/educational-resources/interactives/zoetrope

   kinomatic display    :

   babbage engine       : https://www.computerhistory.org/collections/catalog/X39.81  /  https://www.computerhistory.org/babbage/

   mechanical pixel art : https://www.youtube.com/watch?v=w1ks0Vy98KI

   mechanical clock     : https://www.youtube.com/playlist?list=PLiqrEMrfoE8pOmxFXpOTk7UyUK8hfkwLH

   water display        : https://www.youtube.com/watch?v=L0i-uTa4kv4

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B) electrical logic devices (smaller scale than mechanical devices, so no vaccum tubes / flip displays):

   light gun     : https://www.reddit.com/r/explainlikeimfive/comments/5crto3/eli5_how_does_an_arcade_shooting_machine_works/

   mechanical tv : https://en.wikipedia.org/wiki/Mechanical_television

   crt ram       : https://www.radiomuseum.org/forum/williams_kilburn_williams_kilburn_ram.html

   e-ink         : https://www.visionect.com/blog/electronic-paper-explained-what-is-it-and-how-does-it-work/

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C) virual stuff:

   pixel to spreadsheet : https://leondrolio.com/apps/pixel-spreadsheet/

   mindcraft computer   : https://minecraft.fandom.com/wiki/Tutorials/Redstone_computers  
                       
                          https://www.reddit.com/r/programming/comments/xecijm/someone_made_minecraft_in_minecraft_with_a/

   bash & postscript make it a lot easier to change the display mechanics : https://github.com/tavinus/pdfScale

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That was a miracle. I used to type in programs from magazines and books and nothing ever worked. That did however teach me how to fix things and was very productive in the long run!

Just the other day I was manually modding a json file, because damnit I know better.

Anyway one typo and it borked the whole deal. Lol it is truly difficult sometimes

Just imagine how fast llama3.2 would be without a computer

What do you mean by "programmable computer?"

Today it means: computer. But long long ago there were things called computers (something that computed) that weren't programmable. E.g the computer that aims battleship guns in WW1.

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