Games

749 Articles

Tetris On An Oscilloscope, The Software Way

October 6, 2023 by 8 Comments

When we talk about video games on an oscilloscope, you’d be pardoned for assuming the project involved an analog CRT scope in X-Y mode, with vector graphics for something like Asteroids or BattleZone. Alas, this oscilloscope Tetris (Russian language, English translation) isn’t that at all — but that doesn’t make it any less cool.

If you’re interested in recreating [iliasam]’s build, it’ll probably help to be a retro-oscilloscope collector. The target instrument here is a Tektronix TDS5400, a scope from that awkward time when everything was going digital, but CRTs were still cheaper and better than LCDs. It’s based on a Motorola 68EC040 processor, sports a boatload of discrete ICs on its main PCB, and runs VxWorks for its OS. Tek also provided a 3.5″ floppy drive on this model, to save traces and the like, as well as a debug port, which required [iliasam] to build a custom UART adapter.

All these tools ended up being the keys to the kingdom, but getting the scope to run arbitrary code was still a long and arduous process, with a lot of trial and error. It’s a good story, but the gist is that after dumping the firmware onto the floppy and disassembling it in Ghidra, [iliasam] was able to identify the functions used to draw graphics primitives on the CRT, as well as the functions to read inputs from the control panel. The result is the simple version of Tetris seen in the video below. If you’ve got a similar oscilloscope, the code is up on GitHub.

Care for a more hardware-based game-o-scope? How about a nice game of Pong? Or perhaps a polar breakout-style game is what you’re looking for. Continue reading “Tetris On An Oscilloscope, The Software Way” →

Computer Space Replica Is Up And Running

October 2, 2023 by 8 Comments

You never forget your first time — watching someone pour several quid’s worth of 10p pieces into a Space Invader machine in 1978, upsetting for a youngster who wanted to have a turn. We’re still waiting, but [Alston] has found an interesting way to get around those arcade video game hoggers by building a replica of Computer Space, the first commercial arcade video game.

Released in 1971, the groundbreaking game was designed by gaming legends [Nolan Bushnell] and [Ted Dabney], and came in a striking curvy fiberglass case that was molded by a manufacturer of swimming pools. [Alston] hasn’t built the case yet, but he does have the electronics up and running.

The electronics of Computer Space are interesting, because there is no microprocessor in there. Instead, it is built from discrete components. [Nolan] had originally planned to use a mini computer called the Data General Nova 800. However, he realized that he could make it cheaper by building it out of discrete components. As [Nolan] described it in an oral history at the Smithsonian [PDF link], the idea came to him after a post-Thanksgiving dinner nap:

“Screw the minicomputer. Get rid of it. Do it all in hardware. Make the game out of this collection, just make it a simple state machine. And the minute that happened, it was like knife through butter. Not only did I get the cost down, but what was budgeted for $1,500 worth of minicomputer, the whole damn computer cost me less than $300 in glue parts. So, I knew that I had something.”

That decision makes it an interesting project to build a replica. Although you can emulate it on a modern computer easily (there is even a version that runs in CSS in the browser). [Alston] is going the hard route, building replica PCBs and using the same components where possible, helped by people who have documented it. So far, the boards are and running and displaying a grainy, pixelated image on a portable TV.

The next step is to take the replica electronics box he has built and make a cabinet to put it into. That’s a big project, and [Alston] is looking for someone with an original cabinet that he can examine and document.

A handheld computer made on a piece of prototyping board running a Tetris clone

Tetris Clone Uses 1000 Lines Of Code, And Nothing Else

September 25, 2023 by 18 Comments

If you’re programming on a modern computer, you typically make use of lots of work done by other people. There’s operating systems to abstract away the complexities of modern hardware, standard libraries to implement common tasks, and tons of third-party libraries that prevent you from having to reinvent the wheel all the time: you’re definitely not the first one trying to draw graphics onto a screen or store data in a file.

But if it’s the wheels you’re most interested in, then there’s nothing wrong with inventing new ones now and then. [Michal Zalewski], for instance, has made a beautiful Tetris clone in just 1000 lines of C, without using anyone else’s code.

The purpose of this exercise is to show that it’s possible to make a game with graphics comparable to modern, complex computing systems, without relying on operating systems or third-party libraries. The hardware consists of not much more than an ARM Cortex-M7 MCU, a 240×320 LCD screen and a few buttons soldered onto a piece of prototyping board, all powered by a set of AAA batteries.

The software is similarly spartan: just pure C code running directly on the CPU core. Graphic elements, some generated by AI and others hand-drawn, are stored in memory as plain bitmaps. They are manipulated by 150 lines of code that shuffles sprites around the display at a speed high enough to generate smooth motion. Game mechanics take up about 250 lines, while sound consists of simple square-wave chiptunes written in just 50 lines of code.

[Michal]’s code is very well documented, and his blog post gives even more details about all the problems he had to solve. One example is the length of keypresses: when do you interpret a keypress as a single “press”, and when does it become “press and hold”? Apparently, waiting 250 ms after the first press and 100 ms after subsequent ones does the trick. [Michal] is a bit of an expert on bare-bones game programming by now: he has previously pushed several 8-bit micros to their very limits. Third-party libraries can make your programming life a lot easier, but it’s good to reflect on the dangers of relying too much on other people’s code.

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Latency Meter For Accurate Gaming

September 19, 2023 by 17 Comments

The gaming world experienced a bit of a resurgence in 2020 that is still seen in the present day. Even putting aside the effects from the pandemic, the affordability and accessibility has arguably never been better. Building a gaming PC can have its downsides, though, and a challenging issue to troubleshoot is input lag or input latency. This is something that’s best measured with standalone hardware, and if this is an issue on your setup you may want to take a look at this latency meter.

Unlike other measurement devices that use the time between a mouse button input and the monitor’s display of a bullet or shooting event, this one looks at mouse movement and the change in the scene instead. This makes it much more versatile than other methods since it’s independent of specific actions, and can be used in any game without any specific events needed to perform the measurement. A camera phototransistor is placed on the monitor’s top edge and the Arduino-based device sends mouse commands to the computer while measuring the time between those commands and the shift in the image on the monitor.

The project is open source, so with the right hardware it’s possible to build one to troubleshoot latency issues or just to learn more about a particular hardware configuration’s behavior. Arduinos and other microcontrollers have been doing all kinds of things by pretending to be human interface devices like this for a while now. One of our favorites of late was this effects pedal that replicates musical effects on mice and keyboards.

Implementing MegaTextures On Real Nintendo 64 Hardware

September 19, 2023 by 20 Comments

As amazing and groundbreaking as the Nintendo 64 was, over the years it has also become synonymous with blurry textures and liberal use of Gouraud shading as its most strongly defining visual features. In a recent video, [James Lambert] covers how the system’s minuscule 4 kB texture memory (TMEM) can be circumvented using mipmapping. By loading progressively more detailed textures (each in 4 kB chunks) in a level-of-detail (LoD), the visual fidelity can be maximized while keeping rendering speeds relatively zippy, as the real-time demo proves.

Determining which textures are visible to the player.

This project was made for the N64brew 2023, with the source code available on [James]’s GitHub account. Although impressive, it bears noting that mipmapping was not an unknown approach in 1996, and many approaches were used to work around the N64’s physical limitations.

In the case of mipmapping, [James]’s demo perfectly demonstrates the problematic nature of mipmapping, as it dramatically increases the storage requirements for the textures, hitting 40 MB just for this one single room, for a system that supports up to 64 MB cartridges.

Ultimately, this shows that the 4 kB TMEM was not the only issue with the N64, with the limited (and expensive) mask ROMs for the cartridges proving to be an insurmountable obstacle that systems like Sony’s PlayStation largely did not have to contend with. With roomy 650 MB+ optical storage, the PS1 got instead tripped up by the glacial access and loading speeds of optical media and its soggy-potato-powered GPU.

Seeing demonstrations like these manage to wonderfully highlight the bottlenecks in these old consoles, and makes one wonder about what could have been, even in an era before 1 TB solid-state drives and direct resource streaming between GPU and said storage.

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Atari Introduces A New Old Console

September 11, 2023 by 29 Comments

Readers of a certain age no doubt remember the Atari 2600 — released in 1977, the 8-bit system helped establish the ground rules for gaming consoles as we know them today, all while sporting a swanky faux wood front panel designed to make the system look at home in contemporary living rooms.

Now, nearly 50 years later, the Atari 2600 is back. The new system, imaginatively named the 2600+, looks exactly like the original system, albeit at around 80% scale. It will also work the same way, as the system will actually be able to play original Atari 2600 and 7800 cartridges. This is something of a surprise when compared to the previously released retro consoles from the likes of Sony and Nintendo, as they were all limited to whatever games the company decided to pack into them. Of course, this probably has something to do with the fact that Atari has been selling newly manufactured 2600 games for some time now.

Although it will play original cartridges, it’s still an emulated console at heart. There aren’t a lot of technical details on the product page, but it does say the 2600+ is powered by a Rockchip 3128 SoC with 256 MB of DDR3 RAM and 256 MB eMMC flash. Some quick searching shows this to be a pretty common board for set-top gadgets, and wildly overpowered considering the meager requirements for emulating a game console from 1977. We wouldn’t be surprised to find it’s running some kind of minimal Linux install and using one of the existing open source emulators.

While the 2600+ sports the same 9-pin D-sub controller connectors as the original console, it thankfully embraces modern display technology and outputs over HDMI. Each console will come with a “10-in-1” cartridge that contains some of the console’s most popular titles, as well as a modernized version of the original single-button joystick. (Unlike the original, the 2600+ comes with only a single joystick — the other is sold separately.)

Atari won’t start shipping the 2600+ until this fall, but they’re currently taking preorders for the $130 system. We’re eager to see somebody pull it apart, as the earlier “mini” consoles ended up being ripe for hacking.

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