The Descendants Of Ancient Computers

May 31, 2020 by Bryan Cockfield 13 Comments

Building computers from discrete components is a fairly common hobby project, but it used to be the only way to build a computer until integrated circuits came on the scene. If you’re living in the modern times, however, you can get a computer like this running easily enough, but if you want to dive deep into high performance you’ll need to understand how those components work on a fundamental level.

[Tim] and [Yann] have been working on replicating circuitry found in the CDC6600, the first Cray supercomputer built in the 1960s. Part of what made this computer remarkable was its insane (for the time) clock speed of 10 MHz. This was achieved by using bipolar junction transistors (BJTs) that were capable of switching much more quickly than typical transistors, and by making sure that the support circuitry of resistors and capacitors were tuned to get everything working as efficiently as possible.

The duo found that not only are the BJTs used in the original Cray supercomputer long out of production, but the successors to those transistors are also out of production. Luckily they were able to find one that meets their needs, but it doesn’t seem like there is much demand for a BJT with these characteristics anymore.

[Tim] also posted an interesting discussion about some other methods of speeding up circuitry like this, namely by using reach-through capacitors and Baker clamps. It’s worth a read in its own right, but if you want to see some highlights be sure to check out this 16-bit computer built from individual transistors.

Breathing New Life Into Old School ThinkPad Keyboards

May 26, 2020 by Tom Nardi 6 Comments

The ThinkPad is generally considered the unofficial laptop of hackerdom, so it’s no surprise that we see plenty of projects focused on repairing and modifying these reliable workhorses. But while we usually see folks working on relatively modern incarnations of this iconic line of computers, this project by [Frank Adams] and [Brian Chan] shows that the hacker’s love affair with the ThinkPad stretches back farther than many might realize.

As explained on the project’s Hackaday.io page, the duo have produced an open hardware board that will allow you to take the keyboard and trackpoint from a late ’90s ThinkPad 380ED and use it as a standard USB input device on a modern computer. According to [Frank], the keyboards on these machines are notable for having full-size keys rather than the “chicklet” boards that are so common today.

Now you may be wondering why this is significant. After all, we’ve seen plenty of projects that hook up an old keyboard to a USB-equipped microcontroller to get them speaking the lingua franca. Well, the trick here is that the trackpoint on these older ThinkPads actually required additional circuitry on the motherboard to function. The keyboard features three separate FPC connections for the matrix, the trackpoint buttons, and the analog strain gauges in the trackpoint itself.

After a considerable amount of reverse engineering, [Frank] and [Brian] have developed a board that uses the Teensy 3.2 to turn this plethora of pins into something useful. In the video after the break, you can see the new composite USB device working perfectly on a modern Windows computer.

It will probably come as little surprise to find that [Frank] is no stranger to hacking ThinkPad keyboards. In 2018 we covered a similar adapter he built for the far more modern T61, which was an absolute cakewalk by comparison.

Continue reading “Breathing New Life Into Old School ThinkPad Keyboards” →

A 4-bit Random Number Generator

May 23, 2020 by Jenny List 43 Comments

Randomness is a pursuit in a similar vein to metrology or time and frequency, in that inordinate quantities of effort can be expended in pursuit of its purest form. The Holy Grail is a source of completely unpredictable randomness, and the search for entropy so pure has taken experimenters into the sampling of lava lamps, noise sources, unpredictable timings of user actions in computer systems, and even into sampling radioactive decay. It’s a field that need not be expensive or difficult to work in, as [Henk Mulder] shows us with his 4-bit analogue random number generator.

One of the simplest circuits for generating random analogue noise involves a reverse biased diode in either Zener or avalanche breakdown, and it is a variation on this that he’s using. A reverse biased emitter junction of a transistor produces noise which is amplified by another transistor and then converted to a digital on-off stream of ones and zeroes by a third. Instead of a shift register to create his four bits he’s using four identical circuits, with no clock their outputs randomly change state at will.

A large part of his post is an examination of randomness and what makes a random source. He finds this source to be flawed because it has a bias towards logic one in its output, but we wonder whether the culprit might be the two-transistor circuit and its biasing rather than the noise itself. It also produces a sampling frequency of about 100 kbps, which is a little slow when sampling with he Teensy he’s using.

An understanding of random number generation is both a fascinating and important skill to have. We’ve featured so many RNGs over the years, here’s one powered by memes, and another by a fish tank.

IMac G4 Reborn With Intel NUC Transplant

May 19, 2020 by Tom Nardi 25 Comments

Released in 2002, Apple’s iMac G4 was certainly a unique machine. Even today, its hemispherical case and integrated “gooseneck” display is unlike anything else on the market. Whether or not that’s a good thing is rather subjective of course, but there’s no denying it’s still an attention grabber nearly 20 years after its release. Unfortunately, it’s got less processing power than a modern burner phone.

Which is why [Tom Hightower] figured it was the perfect candidate for a retrofit. Rather than being little more than a display piece, this Intel NUC powered iMac is now able to run the latest version of Mac OS. He even went as far as replacing the display with a higher resolution panel, though it sounds like it was dead to begin with so he didn’t have much choice in the matter.

Somewhere, an early 2000s Apple engineer is screaming.

The retrofit starts off with a brief teardown, which is quite interesting in itself. [Tom] notes a number of unique design elements, chief among them the circular motherboard. The two banks of memory also use different form factors, and only one of them is easily accessible to the end user. Something to think about the next time somebody tells you that Apple’s “brave” hardware choices are only a modern phenomena.

There was plenty of room inside the iMac’s dome to fit the NUC motherboard, and some extension cables and hot glue got the computer’s rear panel suitably updated with the latest-and-greatest ports and connectors. But the conversion wasn’t a total cakewalk. That iconic “gooseneck” put up quite a fight when it was time to run the new wires up to the display. Between the proprietary screws that had to be coerced out with a Dremel to the massive spring that was determined to escape captivity, [Tom] recommends anyone else looking to perform a similar modification just leave the wires on the outside of the thing. That’s what he ended up doing with the power wires for the display inverter.

If you like the idea of reviving old Apple hardware but don’t want to anger the goose, you could start on something a little easier. Like putting an iPad inside of a Macintosh Classic shell.

Help Us Throw More Cycles At The Coronavirus Problem

May 10, 2020 by Mike Szczys 45 Comments

The Hackaday community has answered the call and put their computers put to work folding proteins found in the coronavirus. Team_Hack-a-Day ranks #44 in the world so far this month, and I’ve seen us rank as high as #19 on 24-hour leaderboards.

Want to join the fight? Donate some of those computing cycles you’re not using to battling SARS‑CoV‑2. You’re probably not an epidemiologist or a vaccine researcher, but you can make their jobs easier by providing them with the data they need through the Folding@home Project.

As Dan Maloney explained in his excellent article on protein folding, understanding the incredibly complex folding behavior of the proteins in the virus will be key to finding treatments and possibly a vaccine. Folding@home connects countless computers via the internet and is now the largest supercomputer in the world, consisting of over 3.5 million CPUs and over half a million GPUs. The resulting data is freely available to researchers.

Let’s take a look at how easy it is to get up and running, how a GPU can supercharge a setup, and dip into the stats for Team_Hack-a-Day’s effort.

Continue reading “Help Us Throw More Cycles At The Coronavirus Problem” →

Old Laptop Gets New Lease On Life With Raspberry Pi

May 1, 2020 by Tom Nardi 35 Comments

It seems not a day goes by that we don’t see somebody cramming a Raspberry Pi into some unwilling piece of consumer electronics. But despite being a pretty obvious application for the diminutive ARM board, we don’t often see it installed in an actual computer. Which makes this very clean Raspberry Pi laptop conversion by [Sherbethead2010] all the more interesting.

The first step involved taking a Dremel to the Dell’s chassis and essentially leveling out the entire internal volume. The only component that got reused was the fan, and even that appears to be relocated, so all the mounting posts were just standing in the way of progress.

[Sherbethead2010] mounted the Raspberry Pi towards the rear of the case so its USB and Ethernet ports would be available from the outside, and installed a driver board for the original Phillips LP171 LCD panel in the old drive bay. Power is provided by two custom 18650 battery packs connected to dedicated buck converters, along with an onboard charge controller to safely top them off.

Rather than trying to adapt the original input devices, [Sherbethead2010] decided to take the easy route and installed a Rii K22 wireless keyboard with integrated track pad into the top of the laptop. It turned out to be an almost perfect fit, and beyond the keys being slightly off-center, at first glance it looks like it could be stock.

The last time we saw a Raspberry Pi so well integrated into a real laptop, it was to create a functioning version of one of the props from Hackers. While that build was a joy for its own reasons, it’s hard not to be impressed with how unassuming this computer looks after all the work that’s been done to it.

The United States Air Force Would Like You To Hack Into Their Satellite

April 30, 2020 by Al Williams 16 Comments

The Air Force is again holding its annual “Space Security Challenge” where they invite you to hack into a satellite to test their cybersecurity measures. There are actually two events. In the first one, $150,000 is up for grabs in ten prizes and the final event offers a $100,000 purse divided among the three top participants (first place takes $50,000).

Before you get too excited, you or your team has to first qualify online. The qualification event will be over two days starting May 22. The qualifying event is set up a bit like the TV show Jeopardy. There is a board with categories. When a team solves a challenge in a category it receives a flag that is worth points as well as getting to unlock the next challenge. Once a challenge is unlocked however, any team could potentially work on it. There are more rules, but that’s the gist of it. At the end of the event, the judges will contact the top 10 teams who will then each have to submit a technical paper.

Continue reading “The United States Air Force Would Like You To Hack Into Their Satellite” →