A System Board For The 8008

May 27, 2024 by 26 Comments

Intel processors, at least for PCs, are ubiquitous and have been for decades. Even beyond the chips specifically built by Intel, other companies have used their instruction set to build chips, including AMD and VIA, for nearly as long. They’re so common the shorthand “x86” is used for most of these processors, after Intel’s convention of naming their processors with an “-86” suffix since the 1970s. Not all of their processors share this convention, though, but you’ll have to go even further back in time to find one. [Mark] has brought one into the modern age and is showing off his system board for this 8008 processor.

The 8008 predates any x86 processor by about six years and was among the first mass-produced 8-bit processors even before the well-known 8080. The expansion from four bits to eight was massive for the time and allowed a much wider range of applications for embedded systems and early personal computers. [Mark] goes into some of the details for programming these antique processors before demonstrating his system board. It gets power from a USB-C connection and uses a set of regulators and level shifters to make sure the voltages all match. Support for all the functions the 8008 needs is courtesy of an STM32. That includes the system memory.

For those looking to develop something like this, [Mark] has also added his development tools to a separate GitHub page. Although it’s always a good idea for those interested in computer science to take a look at old processors like these, it’s not always the easiest path to get original hardware like this, which also carries the risk of letting smoke out of delicate components. A much easier route is to spin up an emulator like an 8086 IBM PC emulator on an ESP32. Want to see inside this old chip? Have a look.

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Reinventing Rotary Switches With Stepper Motors

May 27, 2024 by 22 Comments

When you need to make very tiny measurements, even noise in closed relays can throw you off. [Marco] was able to observe this effect and wanted to build a switch that didn’t have this problem. He found a technical paper that used rotary switches operated by stepper motors instead of relays. So he decided to try making his own version. The video below shows how it turned out.

The first part of the video talks about why relays sometimes inject a tiny voltage into a closed circuit. He then looks at costly switches that would work. However, since he needed many switches, he decided to roll his own.

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So What’s All This HaLow Long-Range WiFi About Then?

May 26, 2024 by 18 Comments

We’re all used to wireless networking, but if there’s one thing the ubiquitous WiFi on 2.4 or 5 GHz lacks, it’s range. Inside buildings, it will be stopped in its tracks by anything more than a mediocre wall, and outside, it can be difficult to connect at any useful rate more than a few tens of metres away without resorting to directional antennas and hope. Technologies such as LoRa provide a much longer range at the expense of minuscule bandwidth, but beyond that, there has been little joy. As [Andreas Spiess] points out in a recent video though, this is about to change, as devices using the so-called HaLow or IEEE 802.11ah protocol are starting to edge into the realm of affordability.

Perhaps surprisingly, he finds the 5 GHz variant to be best over a 1km test with a far higher bandwidth. However, we’d say that his use of directional antennas is something of a cheat. Where it does come into its own in his tests, though, is through masonry, with far better penetration across floors of a building. We think that this will translate to better outdoor performance when the line of sight is obstructed.

There’s one more thing he brings to our attention, which seasoned users of LoRA may already be aware of. These lower frequency allocations are different between the USA and Europe, so should you order one for yourself, it would make sense to ensure you have the appropriate model for your continent. Otherwise, we look forward to more HaLow devices appearing and the price falling even further because we think this will lead to some good work in future projects.

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Hackaday Links: May 26, 2024

May 26, 2024 by 5 Comments

Another day, another crop of newly minted minimal astronauts, as Blue Origin’s New Shepard made a successful suborbital flight this week. Everything seemed to go according to plan, at least until right at the end, when an “unexpected foliage contingency” made astronaut egress a little more complicated than usual. The New Shepard capsule had the bad taste to touch down with a bit of West Texas shrubbery directly aligned with the hatch, making it difficult to find good footing for the platform used by the astronauts for the obligatory “smile and wave” upon exiting. The Blue Origin ground crew, clad in their stylish black and blue outfits that must be murderously impractical in the West Texas desert, stamped down the brush to place the stairway, but had a lot of trouble getting it to sit straight. Even with the impromptu landscaping, the terrain made it tough to get good footing without adding random bits of stuff to prop up one leg, an important task considering that one of the new astronauts was a 90-year-old man. It seems pretty short-sighted not to have adjustable legs on the stairway, but there it is.

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How Do You Fill The 1N34 Void?

May 26, 2024 by 31 Comments

The germanium point contact diode, and almost every semiconductor device using germanium, is now obsolete. There was a time when almost every television or radio would have contained one or two of them, but the world has moved on from both analogue broadcasting and discrete analogue electronics in its lower-frequency RF circuitry. [TSBrownie] is taking a look at alternatives to the venerable 1N34A point-contact diode in one of the few places a point-contact diode makes sense, the crystal radio.

In the video below the break, he settles on a slightly more plentiful Eastern European D9K as a substitute after trying a silicon rectifier (awful) and a Schottky diode (great in theory, not so good in practice). We’ve trodden this path in the past and settled on a DC bias to reduce the extra forward voltage needed for a 1N4148 silicon diode to conduct because, like him, we found a Schottky disappointing.

The 1N34 is an interesting component, and we profiled its inventor a few years ago. Meanwhile, it’s worth remembering that sometimes, we just have to let old parts go.

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Weird Old Stereo Accessories

May 26, 2024 by 25 Comments

Some people trick out their cars. Some, their computers. There are even people who max out their audio systems, although back in 1979, there was more of that going on, probably, than today where you discresionary income is split so many ways. Case in point: [Alan Cross] remembers how excited he was to get the Radio Shack catalog that year. He was working at a grocery store, saved his money, and — over time — picked up a haul ranging from an equalizer to a strobe light.

Who didn’t need a power meter or a “light organ?” These gadgets seem cheap until you realize it was 1979 and [Alan] was a student working at a grocery store. He points out that the $20 power meter is about the same as $80 today.

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Homebrew Computer From The Ground Up

May 26, 2024 by 12 Comments

Building a retro computer of some sort is a rite of passage for many of us, with some building replicas or restorations of old Commodores, Ataris, and other machines from decades past. Others go even further back, to the time of the Intel 8008 or earlier, and a dedicated few will build something completely novel. This project from [3DSage] falls squarely in the latter category, with his completely DIY computer built component by component from scratch, including the machine code needed to run it.

[3DSage] starts with the backbone of every computer: the clock. He first demonstrates how a pair of NOT gates with a set of capacitors can be used as a rudimentary clock pulse, then builds a more refined version with a 555 timer and potentiometer for adjustable rates. Then, it’s on to creating a binary counter, which is a fundamental part of the memory system for this small computer, and finally, allows this circuitry to behave like a normal computer. Using a set of switches to store values in memory and stepping through them with the clock, the computer can be programmed to do plenty of tasks just like a modern microcontroller.

[3DSage] built this project a few years ago and has used it for real-world applications such as controlling servos, LED arrays, playing music, and other tasks. Although he has to program it using his own machine code by hand, it’s a usable computer in many ways. If you want to eschew modernity and build a retro computer in the style of the 1960s, though, this piece goes through what it would have been like to build a similar system in the era when these computers were more common. If you have a switch fetish, you might like to see how real computers worked back then, too.

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