Building Video Pong With Discrete Components

Pong is a classic from the very dawn of the video game era. Recreating it remains a popular exercise for those new to coding. However, its simple logic makes this game particularly suited to an all-hardware build; something which [Glen] tackles with aplomb.

Not content to take the easy way out, [Glen] went for a particularly hardcore method of construction. The game uses absolutely zero integrated circuits in its construction. Instead, it relies upon the services of 431 bipolar transistors, 6 JFETs and 826 diodes. Everything is laced together on protoboard, connected with a neatly organised nest of colored wires. Schematics are available for the curious.

It’s a full featured build, too. Video output is in color, scores are displayed at the top of the screen, and there’s even stereo panning for the sound effects. It just goes to show what some humble components can do when put to work in the right way. We’ve seen some of [Glen]’s work before too, for example in this op-amp bouncing ball device. Video after the break.

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Logic And EEPROMs Bring VGA To Life, Sans Microcontroller

For whatever reason, the Video Graphics Array standard seems to attract a lot of hardware hacks. Most of them tend to center around tricking a microcontroller into generating the signals needed to send images to a VGA monitor. We love those hacks, but this one takes a different tack – a microcontroller-free VGA display that uses only simple logic chips and EEPROMs.

When we first spied this project, [PH4Nz] had not yet shared his schematics and code, but has since posted everything on GitHub. His original description was enough to whet our appetite, though. He starts with a 27.175-MHz clock and divides that by 4 with a 74HCT163, which has the effect of expanding the 160×240 pixels image stored in one of the EEPROMs to 640×480. Two 8-bit counters keep track of horizontal and vertical positions, while the other EEPROM takes care of generating the Hsync and Vsync signals. It’s all quite hackish, but it works. [PH4Nz] tells us that the whole thing is in support of a larger project: an 8-bit computer made from logic chips. We’re looking forward to seeing that one too.

This isn’t the first microcontroller-less VGA project we’ve seen, of course. Here’s a similar one also based on EEPROMs, and one with TTL logic chips. And we still love VGA on a microcontroller such as the ESP32; after all, there’s more than one way to hack.

Thanks to [John U] for the tip.

Discrete Pong Project Goes Big, Adds A Player

Some projects just take on a life of their own. What started as a pleasant diversion or a simple challenge becomes an obsession, and the next thing you know you’ve built a two-player color Pong game with audio completely from discrete components.

If this one seems familiar, it’s because we were dazzled by its first incarnation last year. As impressive as version 1.0 was, all the more so since it was built using the Manhattan method and seemingly over the course of a weekend, it did have its limitations. [GK] has been refining his design ever since and keeping accurate track of the process, to the tune of 22 pages on the EEVblog forum. We haven’t pored through it all yet, but the state of the project now is certainly worth a look. The original X-Y output to an oscilloscope was swapped out to composite video for a monitor, in both mono and color. This version also allows two people to play head-to-head instead of just battling the machine. It looks like [GK] had to add a couple of blocks worth of real estate to his Manhattan board to accommodate the changes, and he tidied the wiring significantly while he was at it.

It’s a project that keeps on giving, so feast your eyes and learn. We suspect [GK] doesn’t have any plans to finish this soon, but if he does, we can’t wait to see what’s next.

Thanks to [David Gustafik] for reminding us to check back on this one.

Hackaday Prize Entry: A Mess Of VGA On A Breadboard

Before all our video games came over the Intertubes, before they were on CDs, and before they were on cartridges, video games were all discrete logic. Pong was the first and you can build that out of several dozen logic chips. The great [Woz] famously built Breakout out of 44 simple chips.

For [Marcel]’s entry to the Hackaday Prize, he’s taking the single board microprocessor-less computer to the next level. He’s building a multi-Megahertz 64-color computer on a breadboard. What’s the capacitance of a breadboard? Just ask [Marcel].

The design of this disintegrated computer has just about everything you could want in a discrete CPU. There is no microcontroller or complex chips like the 74181 ALU, there’s pipelining with sometimes two instructions per clock, decoding with diodes, and a 60 Hz, 64 color VGA output and four sound channels. There’s only about 40 TTL chips on this board.

The project logs for this Hackaday Prize entry are a treat in themsleves, ranging from topics to the implementation of NES controllers to getting rid of the breadboard and turning this computer into something like a vintage game system, but with a custom CPU and instruction set. It’s an amazing build, and an awesome project for the Hackaday Prize.

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Relay Computer: You Can Hear It Think

Modern digital computers have complex instruction sets that runs on state-of-the-art ALUs which in turn are a consequence of miniaturized logic gates that are built with tiny transistors. These tiny transistors are essentially switches. You could imagine replacing with electromagnetic relays, and get what is called a relay computer. If you can imagine it, someone’s done it. In this case, [jhallenworld].

The Z3 was the first working programmable, fully automatic digital computer designed by Konrad Zuse. The board employs modern semiconductor devices such as memory and microcontrollers, however, the CPU is all relays. A hexadecimal keyboard allows for program entry and a segment display allows tracking the address and data. The program is piped into serial to the parallel decoder and fed to the CPU where the magic happens. Since the core is electromechanical it is possible to connect the output to peripherals such as a bell as demonstrated near the end of the video.

This project is a good balance of retro and modern to be useful to anyone interested in mechanical computers and should be a lot of fun for the geek kind. Hacking this computer to modify the instruction set should be equally rewarding and a good exercise for students of computing theory.

There is a SourceForge page dedicated to the project with the details on the project including the instruction set and architecture. Check out the video below and if you are inspired by the project, be sure to check out the [Clickity Clack]’a Videos on designing a relay computer bit by bit.

Dis-Integrated 6502 Running Programs; Acting Like Computer

[Eric Schlaepfer] tends to turn up to Maker Faire with projects you simply don’t want to miss. This year is no different. Twelve months ago we delighted in seeing his 6502 processor built from an enormous reel of discrete MOSFETs. At the time it was freshly built and running random code to happily blink the LEDs reflecting activity in the registers. This year he’s given that blinking meaning and is running real programs on his Monster 6502 processor.

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Relay Computer Starts With An Adder That Makes A Racket

Computers built using discrete logic chips? Seen it. Computers from individual transistors? Impressive, but it’s been done. A computer built out of electromechanical relays? Bring on the ozone!

The aptly named [Clickity Clack]’s new YouTube channel promises to be very interesting if he can actually pull off a working computer using nothing but relays. But even if he doesn’t get beyond the three videos in the playlist already, the channel is definitely worth checking out. We’ve never seen a simpler, clearer explanation of binary logic, and [Clickity Clack]’s relay version of the basic logic gates is a great introduction to the concepts.

Using custom PCBs hosting banks of DPDT relays, he progresses from the basic AND and XOR gates to half adders and full adders, explaining how carry in and carry out works. Everything is modular, so four of his 4-bit adder cards eventually get together to form a 16-bit adder, which we assume will be used to build out a very noisy yet entertaining ALU. We’re looking forward to that and relay implementations of the flip-flops and other elements he’ll need for a full computer.

And pay no mind to our earlier dismissal of non-traditional computer projects. It’s worth checking out this discrete 7400 logic computer and this all-transistor build. They’re impressive too in their own way, if a bit quieter than [Clickety Clack]’s project.

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