Version 1.8 of the 80386 ISA SBC in its assembled glory. (Credit: Alexandru Groza)

Building Your Own 80386DX ISA Single Board Microcomputer

March 30, 2022 by Maya Posch 36 Comments

Having grown up with 386-level systems during the early 90s like so many of us, [Alexandru Groza] experienced an intense longing to experience the nostalgia of these computer systems from an interesting angle: by building his own 80386DX-based single board computer. Courtesy of the 16-bit ISA form factor, the entire system fits into a 16-bit ISA backplane which then provides power and expansion slots for further functionality beyond what is integrated on the SBMC card.

Having started the project in 2019, it is now in the home stretch towards completion. Featuring an 80386DX and 80387DX FPU alongside 128 kB of cache and a grand total of 32 MB of RAM, an OPTi chipset was used to connect with the rest of the system alongside the standard 8042-class PS/2 keyboard and mouse controller. A large part of the fun of assembling such a system is that while the parts themselves are easy enough to obtain, finding datasheets is hard to impossible for some components.

Undeterred, some reverse-engineering of signaling on functional mainboards was sufficient to fill in the missing details. Helpfully, [Alexandru] provides the full schematics and BOM of the resulting board and takes us along with bootstrapping the system after obtaining the PCBs and components. After an initial facepalm moment due to an incorrectly inserted (and subsequently very dead) CPU and boot issues, ultimately [Alexandru] gave up on the v1.6 revision of the board

Fortunately the v1.8 revision with a logic analyzer led to a number of discoveries that has led to the system mostly working, minus what appears to be DMA-related issues. Even so, it is a remarkable achievement that demonstrates the complexity of these old systems.

Retro Portable Computer Packs Printer For The Trip

March 28, 2022 by Tom Nardi 10 Comments

Looking like it dropped out of an alternate reality version of the 1980s, the Joopyter Personal Terminal is a 3D printed portable computer that includes everything you need for life in the retro-futuristic fastlane: a mechanical keyboard, a thermal printer, and the obligatory tiny offset screen. It’s a true mobile machine too, thanks to it’s onboard battery and a clever hinge design that lets you fold the whole thing up into something akin to a PLA handbag. You won’t want to leave home without it.

This gorgeous machine comes our way from [Gian], and while the design isn’t exactly open source, there’s enough information in the GitHub repository that you could certainly put together something similar if you were so inclined. While they might not serve as documentation in the traditional sense, we do love the faux vintage advertisements that have been included.

The upper section of the Joopyter holds a Raspberry Pi Zero W (though the new Pi Zero 2 would be a welcome drop-in upgrade), an Adafruit PiTFT 2.8″ display, a CSN-A2 panel mount thermal printer, and a Anker PowerCore 15600 battery to keep it all running. On the opposite side of the hinge is a hand wired keyboard powered by a Raspberry Pi Pico running KMK.

Speaking of that printed hinge, [Gian] says it comes on loan from [YARH.IO], which Hackaday readers may recall have produced a number of very slick 3D printed portable Linux machines powered by the Raspberry Pi over the last couple of years.

Continue reading “Retro Portable Computer Packs Printer For The Trip” →

Copper Modding Helps Cool A Toasty GPU

March 24, 2022 by Lewin Day 35 Comments

[DandyWorks] had an NVIDIA RTX 3070 Ti GPU, and found it was running incredibly hot, with the card’s memory hitting temperatures of 110 °C. He decided to try “copper modding” to solve the problem, and made some impressive improvements along the way.

Copper modding is where small copper shims are used to connect hot chips on the GPU to the heatsink more effectively than the standard thermal pads used by the manufacturer. Copper has much better thermal conductivity than thermal pads, and thus can help improve cooling of components when used in this fashion.

With the GPU carefully disassembled, [DandyWorks] notes the design uses a sub-heatsink specifically for the memory chips. He then sets about removing the thermal pads from the chips with isopropyl alcohol to help. They’re replaced with copper shims of a precise thickness, with a thin layer of thermal paste to ensure good heat flow. [DandyWorks] also shields all surrounding parts of the board with Kapton tape to avoid shorts if the copper shims happen to shift at any point.

Running the same hashing operation, the GPU now operates with its memory at a much cooler temperature of just 64 °C. [DandyWorks] ran the test for hours and temperatures didn’t climb beyond there. It’s evidence that the copper shims do a far better job of conducting the heat out of the memory chips versus the stock thermal pad setup.

We’ve seen some other interesting mods in this vein before, such as CPU die lapping for better thermal performance. Video after the break.

Continue reading “Copper Modding Helps Cool A Toasty GPU” →

Clockwork DevTerm R-01 Takes RISC-V Out For A Spin

March 19, 2022 by Tom Nardi 23 Comments

If you’re anything like us you’ve been keeping a close eye on the development of RISC-V: an open standard instruction set architecture (ISA) that’s been threatening to change the computing status quo for what seems like forever. From its humble beginnings as a teaching tool in Berkeley’s Parallel Computing Lab in 2010, it’s popped up in various development boards and gadgets from time to time. It even showed up in the 2019 Hackaday Supercon badge, albeit in FPGA form. But getting your hands on an actual RISC-V computer has been another story entirely. Until now, that is.

Clockwork has recently announced the availability of the DevTerm R-01, a variant of their existing portable computer that’s powered by a RISC-V module rather than the ARM chips featured in the earlier A04 and A06 models. Interestingly the newest member of the family is actually the cheapest at $239 USD, though it’s worth mentioning that not only does this new model only include 1 GB of RAM, but the product page makes it clear that the RISC-V version is intended for experienced penguin wranglers who aren’t afraid of the occasional bug.

Newbies are persona non grata for the R-01.

Beyond the RISC-V CPU and slimmed down main memory, this is the same DevTerm that our very own [Donald Papp] reviewed earlier this month. Thanks to the modular nature of the portable machine, this sort of component swapping is a breeze, though frankly we’re impressed that the Clockwork team is willing to go out on such a limb this early in the product’s life. In our first look at the device we figured at best they would release an updated CPU board to accommodate the Raspberry Pi 4 Compute Module, but supporting a whole new architecture is a considerably bolder move. One wonders that other plans they may have for the retro-futuristic machine. Perhaps a low-power x86 chip isn’t out of the question?

A small circuit board glowing purple inset with computer code

Power Cycling Museum Computers On The Cheap

March 18, 2022 by Chris Wilkinson 32 Comments

Flicking a circuit breaker to power cycle hundreds of desktop computers inside interactive museum exhibits is hardly ideal. Computers tend to get cranky when improperly shutdown, and there’s an non-zero risk of data loss. However, financial concerns ruled out commercial computer management solutions, and manually shutting down each exhibit at the end of the day is not practical. Tasked with finding a solution, [Jeff Glass] mixed off-the-shelf UPS (uninterruptible power supply) hardware, a Featherwing and some Python to give the museum’s computer-run exhibits a fighting chance.

Without drastically changing the one-touch end-of-day procedure, the only way to properly shutdown the hundreds of computers embedded in the museum exhibits involved using several UPS units, keeping the PCs briefly powered on after the mains power was cut. This in itself solves nothing – while the UPS can trigger a safe shutdown via USB, this signal could only be received by a single PC. These are off-the-shelf consumer grade units, and were never intended to safely shut down more than one computer at a time. However, each 300 watt UPS unit is very capable of powering multiple computers, the only limitation is the shutdown signal and the single USB connection.

To get around this, the Windows task scheduling service was setup to be triggered by the UPS shutdown signal, which itself then triggered a custom Python script. This script then relays the shutdown signal from the UPS to every other computer in the museum, before shutting itself down for the evening.

While many computers can be enabled to boot on power loss, the UPS and safe shutdown scripts meant that this wasn’t an option. To get around this, an ESP32 Featherwing and a little bit if CircuitPython code sends out WOL (wake-on-LAN) signals over Ethernet automatically on power up. This unit is powered by a non-UPS backed power outlet, meaning that it only sends the WOL signal in the morning when mains power is restored via the circuit breaker.

There are undoubtedly a variety of alternative solutions that appear ‘better’ on paper, but these may gloss over the potential costs and disruption to a multi-acre museum. Working within the constraints of reality means that the less obvious fix often ends up being the right one. How would you have tackled this problem? Sound off in the comments below. And while you’re here, make sure to check out our coverage of other UPS solutions, like this supercap UPS.

An Old Typewriter Speaks To The World

March 17, 2022 by Jenny List 20 Comments

Typewriters are something which was once ubiquitous, yet which abruptly faded away and are now a rare sight. There was a period of a few years in which electric typewriters and computers existed side-by-side though, and it’s one of these which [Jonah Brüchert] has experimented with connecting to a computer for use as a printer or terminal.

The machine in question is a SIGMA SM 8200i typewriter, which is a rebadged version of the East German Erika S3004. It has an intriguing 26-pin connector on its side which provides access to a 1200 baud serial port. It uses its own character encoding dubbed “gdrascii”, for which there is a Python library that he could port to Rust. The result is a terminal in the old style, from the days when access to a computer was through a teletype rather than a screen. All that’s missing is a punched tape reader at its side!

We’ve featured a lot of typewriters here over the ears, but this isn’t the first that has received a terminal conversion.

Mini PC with the mod described, a large tower fan sticking out of a hole in the top cover

MiniPC Surgery Makes It 50% Cooler

March 13, 2022 by Arya Voronova 27 Comments

[G3R] writes to us about a mod they did on a HP ProDesk/EliteDesk 400 G3 miniPC they use as a home emulation center. The miniPC would overheat as soon as the CPU load increased, resulting in frame drops and stutters, as well as throttling CPU. [G3R] took the original cooling solution, threw out half of it and modified the remaining half to accept a tower CPU cooler.

The modification is invasive in all the right ways. [G3R] shows how to de-fin the current heatsink and smooth it over with a… welder? Our guess is that the heatsink fins were soldered to the heatsink base, and in that case, a heat gun should also work. Afterwards, you’re supposed to cut a hole in the upper case, then re-wire the fan connections, and create custom brackets to attach the tower fan – [G3R] explains how to do it all and what to watch out for.

The results are fascinating. After performing the mod, both idle and under-load temps got cut down by 50%! Idle temps went from 50 to 25 °C, and under-load temps dropped from 79 to 40 °C – surely, with way less throttling involved. Not only this lets [G3R] play Breath Of The Wild without hiccups, it also certainly improves overall lifespan of the mini-PC, despite the intervention being mechanically harsh.

Making our devices, quite literally, cooler is a venerable tradition of hackers. Just a few weeks ago, we covered a simple 3D printable LGA 1700 CPU bracket which can gain you some much-desired thermal contact. Sometimes we encounter proprietary and weird cooling fans that fail, and then we understand their workings and build a substitute. And, even if your GPU was never meant to have a fan, you can add one anyway!