Hackaday Links: March 15, 2026

March 15, 2026 by Tom Nardi 3 Comments

Some days, it feels like we’re getting all the bad parts of cyberpunk and none of the cool stuff. Megacorps and cyber warfare? Check. Flying cars and holograms? Not quite yet. This week, things took a further turn for the dystopian with the news that a woman was hospitalized after an altercation with a humanoid robot in Macau. Police arrived on scene, took the bot into custody, and later told the media they believed this was the first time Chinese authorities had been called to intervene between a robot and a human.

The woman, reportedly in her seventies, was apparently shocked when she realized the robot was standing behind her. After the dust settled, the police determined it was being operated remotely as part of a promotion for a local business. We’ve heard there’s no such thing as bad publicity, but we’re not sure the maxim holds true when you manage to put an old lady into the hospital with your ad campaign.

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Capacitor Memory Makes Homebrew Relay Computer Historically Plausible

March 5, 2026 by Tyler August 21 Comments

It’s one thing to create your own relay-based computer; that’s already impressive enough, but what really makes [DiPDoT]’s design special– at least after this latest video— is swapping the SRAM he had been using for historically-plausible capacitor-based memory.

A relay-based computer is really a 1940s type of design. There are various memory types that would have been available in those days, but suitable CRTs for Williams Tues are hard to come by these days, mercury delay lines have the obvious toxicity issue, and core rope memory requires granny-level threading skills. That leaves mechanical or electromechanical memory like [Konrad Zuse] used in the 30s, or capacitors. he chose to make his memory with capacitors.

It’s pretty obvious when you think about it that you can use a capacitor as memory: charged/discharged lets each capacitor store one bit. Charge is 1, discharged is 0. Of course to read the capacitor it must be discharged (if charged) but most early memory has that same read-means-erase pattern. More annoying is that you can’t overwrite a 1 with a 0– a separate ‘clear’ circuit is needed to empty the capacitor. Since his relay computer was using SRAM, it wasn’t set up to do this clear operation.

He demonstrates an auto-clearing memory circuit on breadboard, using 3 relays and a capacitor, so the existing relay computer architecture doesn’t need to change. Addressing is a bit of a cheat, in terms of 1940s tech, as he’s using modern diodes– though of course, tube diodes or point-contact diodes could conceivably pressed into service if one was playing purist. He’s also using LEDs to avoid the voltage draw and power requirements of incandescent indicator lamps. Call it a hack.

He demonstrates his circuit on breadboard– first with a 4-bit word, and then scaled up to 16-bit, before going all way to a massive 8-bytes hooked into the backplane of his Altair-esque relay computer. If you watch nothing else, jump fifteen minutes in to have the rare pleasure of watching a program being input via front panel with a complete explanation. If you have a few extra seconds, stay for the satisfyingly clicky run of the loop. The bonus 8-byte program [DiPDoT] runs at the end of the video is pure AMSR, too.

Yeah, it’s not going to solve the rampocalypse, any more than the initial build of this computer helped with GPU prices. That’s not the point. The point is clack clack clack clack clack, and if that doesn’t appeal, we don’t know what to tell you.

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Surviving The RAM Price Squeeze With Linux In-Kernel Memory Compression

January 31, 2026 by John Elliot V 42 Comments

You’ve probably heard — we’re currently experiencing very high RAM prices due mostly to increased demand from AI data centers.

If you’ve been priced out of new RAM you are going to want to get as much value out of the RAM you already have as possible, and that’s where today’s hack comes in: if you’re on a Debian system read about ZRam for how to install and configure zram-tools to enable and manage the Linux kernel facilities that enable compressed RAM by integrating with the swap-enabled virtual memory system. We’ve seen it done with the Raspberry Pi, and the concept is the same.

Ubuntu users should check out systemd-zram-generator instead, and be aware that zram might already be installed and configured by default on your Ubuntu Desktop system.

If you’re interested in the history of in-kernel memory compression LWN.net has an old article covering the technology as it was gestating back in 2013: In-kernel Memory Compression. For those trying to get a grip on what has happened with RAM prices in recent history, a good place to track memory prices is memory.net and if you swing by you can see that a lot of RAM has gone up as much as four times in the last three or four months.

If you have any tips or hacks for memory compression on other platforms we would love to hear from you in the comments section!

Post-rampocalyptic Chip-Swap Provides Desktop Memory At Laptop Prices

January 27, 2026 by Tyler August 21 Comments

When you can buy something at a low price in one location, and sell it at a higher price somewhere else, you’re engaged in what economists call “arbitrage”. We’re not sure if desoldering DDR5 chips from laptop SO-DIMMs to populate a custom PCB to create much-more-expensive desktop memory counts as arbitrage, but it certainly counts as a hack. [VIK-on], who built the cards, claims he’s getting DDR5 performance at almost DDR3 prices. Nice!

Installed, the RAM apparently works well, though [VIK-on] has not shared benchmarks.

Specifically, he’s put together a 32 GB UDIMM from donor chips from two 16 GB SO-DIMMs. The memory chips themselves aren’t enough to make a stick of RAM, however: the part where we wish we had more details was in the firmware. The firmware identifies this DIY DIMM as an ADATA AX5U6500C3232G-DCLARWH, specifically. [VIK-on] is still performing stability tests, if those go well, we’re told to expect a how-to guide.

[VIK-on] is in Russia, so SO-DIMM rates may differ in your local market, but he claims walkaway costs of 17,015 ₽ — about $218 or €188, an astounding price for DDR5 in these dark days.

Some say soldering SIMMs seems severe, but hardly strange to Hackaday, and desperate times call for desperate measures. It’s ether that or optimize software, and who wants go to that effort?

RAM Prices Got You Down? Try DDR3. Seriously!

January 20, 2026 by Tyler August 44 Comments

DDR3 seemed plenty fast when it first showed up 19 years ago. Who could say no to 6400 Mb/s transfer speeds? Of course compared to the modern DDR5 that’s glacially slow, but given that RAM is worth its weight in gold these days– with even DDR4 spiking in price– some people, like [Gheeotine], are asking “can you game on DDR3“? The answer is a shocking yes.

[Gheeotine] builds two budget-friendly PCs for this video, using some of the newest DD3-supporting motherboards available. That’s not exactly new: we’re talking 12 to 15 years old, but hey, not old enough to drive. We certainly didn’t expect to hear about an x79 motherboard hosting an Ivy Bridge processor in 2026, but needs must when the devil dances. The only concession to modernity is the graphics cards: the x79 mobo got an RX6600XT 8GB, and the other build, using a z97 motherboard got an NVIDIA RTX 4060. The z97 motherboard allowed a slightly newer processor, as well, an i7 4790, with the new and exciting Haswell architecture you may have heard of. Both boards are maxed out on RAM, because at less than one USD/GB, why not?

[Gheeotine] puts a few new titles through their paces on these boxen, and while the results aren’t amazing, everything he tries comes out playable, which is amazing in and of itself. Well, playable unless you’re one of those people who can’t stand playing at resolutions under 4K or FPS under 100. Those of who spent their formative years with 29.7 FPS or 25 FPS in NTSC or PAL regions aren’t going to complain too loudly if frame rates dip down into the 30s playing at 1080p for some of the more demanding titles. Ironically, one of those was the five-year-old Crysis Remastered. Given the age of some of this hardware “Can it Run Crysis” is a perfectly reasonable question, and the answer is still yes.

If you want modern games, you’re much better off with a z97 chipset motherboard if you chose to go the DDR3 route, since you won’t run into issues related to the AVX2 instruction, which first appeared with the Haswell microarchitecture. Here at Hackaday our preferred solution to the rampocalypse is software optimization, Since holding your breath for that would probably be fatal, cost-optimizing PC builds is probably a good plan, even if some might balk at going all the way back to DDR3.

Of course if you’re going to use nearly-retro hardware like DDR3, you might as well go all-out on retro vibes with a nostalgic 80s-style, or even 50s-style case.

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Making RAM For A TMS9900 Homebrew Computer

October 29, 2025 by John Elliot V 7 Comments

Over on YouTube [Usagi Electric] shows us how to make RAM for the TMS9900.

He starts by remarking that the TI-99/4A computer is an excellent place to start if you’re interested in getting into retro-computing. Particularly there are a lot of great resources online, including arcadeshopper.com and the AtariAge forums.

The CPU in the TI-99 is the TMS9900. As [Usagi Electric] explains in the video this CPU only has a few registers and most actual “registers” are actually locations in RAM. Because of this you can’t do much with a TMS9900 without RAM attached. So he sets about making some RAM for his homebrew TMS9900 board. He uses Mitsubishi M58725P 16 kilobit (2 kilobyte) static RAM integrated circuits; each has 11 address lines and 8 data lines, so by putting two side-by-side we get support for 16-bit words. Using six M58725Ps, in three pairs, we get 6 kilowords (12 kilobytes).

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Mushrooms As Computer Memory

October 28, 2025 by Bryan Cockfield 35 Comments

Fungi make up a massive, interconnected part of Earth’s ecosystems, yet they’re vastly underrepresented in research and public consciousness compared to plants and animals. That may change in the future though, as a group of researchers at The Ohio State University have found a way to use fungi as organic memristors — hinting at a possible future where fungal networks help power our computing devices.

A memristor is a passive electronic component whose resistance changes based on the voltage and current that has passed through it, which means it can effectively remember past electrical states even when power is removed. To create these circuit components with fungus, the researchers grew shiitake and button mushroom mycelium for these tests, dehydrated their samples for a number of days, and then attached electrodes to the samples. After misting them briefly to restore conductivity, the samples were exposed to various electrical wave forms at a range of voltages to determine how effective they were at performing the duties of a memristor. At one volt these systems were the most consistent, and they were even programmed to act like RAM where they achieved a frequency of almost 6 kHz and an accuracy of 90%.

In their paper, the research group notes a number of advantages to building fungal-based components like these, namely that they are much more environmentally friendly and don’t require the rare earth metals that typical circuit components do. They’re also easier to grow than other types of neural organoids, require less power, weigh less, and shiitake specifically is notable for its radiation resistance as well. Some work needs to be done to decrease the size required, and with time perhaps we’ll see more fungi-based electrical components like these.