TechyMagThings

Although e-paper displays are famous for being low-power and lasting essentially forever if not damaged physically, the recent push to drive even cheaper e-paper displays at a framerate like 30 FPS for a decent monochrome gaming experience does raise a few questions. The first being what this does to the power usage of these displays, and the second whether this will wear out the display in short order. To investigate this, [Bo Made It] set up a few experiments.

Subject of this test was a Waveshare ESP32-S3-ePaper board, which had previously been demonstrated running a Game Boy emulator at 30 FPS. With this software running, the board consumed on average about 115 mA, which would run down the device’s 400 mAh battery in about 3.5 hours. From here key was to isolate the power consumption of the display itself, with the system minus the display updates consuming about 90 mA.

Running the frame calculations for the greyscale mode without rendering to the screen pushed that up to 107.6 mA, with even in the 30 FPS greyscale mode the display thus only consuming about 7.4 mA, which is vanishingly small. Clearly the low-power claims of e-paper remain intact even at higher framerates.

As for lifespan, one datasheet gives the typical lifespan as one million updates. This would translate to about 9.3 hours at 30 FPS, though that assumes a full display refresh. Since a smart driver only updates changed pixels, obviously this will be longer, but the question is how much longer, and what will degradation look like?

After running 2.16 million frames of a custom endurance test featuring repeating patterns, some ghosting was apparent, but repeated refreshing made this go away again. This means that so far no permanent damage has been detected within the no doubt conservative limit provided by e-paper manufacturers.

It should be noted that Waveshare itself also recommends against running such high-FPS applications on their device, meaning that this is definitely one big longevity experiment. If actual damage occurs, this means that obviously this won’t be covered under any warranty.

If you’ve got an MX-style keyboard and want some retro charm, you might like a recent project from [Levente Szabadkai]. It’s a set of C64-style keycaps that you can print yourself at home!

The project started as an attempt to produce a set of C64 keycaps for an Ajazz 75% keyboard layout, but [Levente] kept pushing until it developed into a universal set. The keys have C64 legends, plain legends, or blank, and work for ANSI boards from 60% to full size. There are a few ways they can be printed. — you can do two-color printing with an FDM machine, or you can print the caps alone and fill the legends with paint, either in FDM or resin.

As a part of this work, [Levente] had to obviously create the glyphs to print upon all the keycaps. He thus decided to release that as the C64 keyboard font, in fact. It’s available in TTF and OTF formats, and you can preview the font in your browser, if so desired. It includes the function key labels, the 63 PETSCII graphic font legends, and various symbols, punctuation, and selected accented letters, too.

We’ve seen lots of vintage C64 parts recreated from scratch. It’s been at the point for a while where you can build a new machine with what’s available off the shelf. They said Amiga would never die, but it’s the earlier Commodore that really lives on today…

Having watched some fun videos on repurposed satellite dishes on YouTube, [Melan] wanted to get in on the action. She managed to source herself an Intellian i4, a dish built for marine use, and set about hacking it to do her bidding.

[Melan] first set about convincing the antenna that it was still on a boat by using an RP2040 microcontroller and an RS-422 module to send NMEA sentences. This was necessary to tell the i4 the “heading” of the “boat”, even though [Melan] was really using the rig on land. From there, she was able to get the Intellian software to run the antenna just by emailing the company.

However, she wanted to see if it could be controlled without it. She began by sniffing communications between the software and the Antenna Control Unit, and decompiling the code. It was relatively straightforward to put together a protocol description and figure out how to command the antenna where to point simply by issuing commands for azimuth and elevation.

We’ve featured other great bits of satellite equipment before, like this truck tracker teardown from a few years ago. If you’ve got some nice equipment on the bench that listens in on (or transmits out to) birds in space, don’t hesitate to let us know on the tipsline.

Airborne micro particles can be a significant health hazard in a workshop, and thus it’s important to maintain a high standard of ventilation. But monitoring their concentration is also important, and thus there exists a range of sensors to help keep you safe. [WeSpeakEnglish] has taken this idea to the MAX, with a PM2.5 sensor that drives a very large wall mounted display. You’ll never be uncertain what the level is now!

The standout feature of this thing is a huge addressable LED seven segment display PCB, upon the back of which sits a tiny Seeed Studio Xiao board to which the particle sensor is hooked up. The software displays the particle count, and handily changes the colour as the number creeps upwards. Meanwhile should you wish to log the readings, the USB exposes a serial port upon which they are placed.

We can see this is a useful project for anywhere that is likely to have a high particle count, but it’s worth noting also that a large 7-segment display with an ESP32 board attached could have plenty of other uses. Meanwhile this is a nicely finished air quality monitor, but it’s certainly not the first we’ve seen.

If we care to cast an eye over the history of ubiquitous personal computing as we know it today, we might immediately point at the original IBM PC. After all, for most of us our machines share backward compatibility in some form through multiple generations back to that original box from 1981.

But if we look at the things we use today and take for granted, from laser printers to graphics cards to the routers which power most of the Internet, they’re not from IBM at all. At the recent Vintage Computing Festival Berlin, [Michael Engel] delivered a talk naming a surprising progenitor for much of that technology, none other than Sun Microsystems.

It all starts with [Andy Bechtolsheim], famously Sun’s co-founder, when at the end of the 1970s he was a postgraduate at Stanford University. Working on the Stanford University Network — SUN — project he designed a computer to be used as a workstation on the network. The processor of choice then was Motorola’s 68000, but it lacked the MMU that would be required to run UNIX. His design had an MMU implemented externally to the 68000, with a bank of SRAM serving as the page table. This design would form the CPU board of the first Sun workstation.

The story might end there, were it not that many other companies had the same requirement, and Sun could supply them a CPU board. Silicon Graphics, the distant ancestral progenitor of your GPU, was one of them, so the first SGI workstation also had the same CPU as the first Sun. It appeared in the early Imagen laser printers too, as well as commercial AppleTalk to Ethernet bridges. Perhaps the biggest surprise is that because the original Stanford board had also been used as a router, the software for that became part of Cisco’s first product.

The video is below the break, and it’s a fascinating watch.

The humble credit card reader — most of us have used hundreds, perhaps even thousands of them over the years. But even for folks like us, it’s not the sort of device we give a lot of thought to. It’s just a keypad, a display, and a magnetic stripe reader. How interesting could it possibly be?

That may be true in some cases, but at least for the 1990s-era TRANZ 330, there’s a bit more to the story than that. As [CharlesD] explains, these particular readers are essentially complete Z80 computers just waiting to do something more exciting than processing PINs. In the case of this particular unit, the addition of a GPS module and some new code has turned it into an interactive guide to the solar system.

Thanks to the UV erasable ROMs used in the TRANZ 330, loading new code on the device is easy enough. With a bit of educated poking around, [CharlesD] was able to map out what did what. Working from the basics of getting the display and keypad working, he moved onto the serial interface, which in turn let him communicate with a modern GPS module and era-appropriate thermal printer. From there it was just a matter of getting the math implemented to compute the azimuth and elevation of a given planet, and he had an offline map of the solar system for use with his telescope.

This is one of those projects which is awesome enough on its own merits, but it’s particularly exciting to see just how easy it is to repurpose one of these card readers, especially since [CharlesD] was kind enough to share his source code. If you end up picking one of these up and getting something running on it, be sure to let us know.

In the open source world we are used to software being compiled from source for our particular distro, so while in a few cases an ancient release may still be in use, it’s just going to run on the latest distro version. But in the Windows world it’s rare for software to come with the source, so you’re left with a binary that will only run if your Windows version has the right APIs for it. Since the more recent versions of Windows dropped 16-bit support a while back, that means there must be a hard date set on the earliest Windows GUI application that can still run today. [Enlyth] decided to investigate.

Given that the earliest API supported in WIndows 11 is the 32-bit version, the hunt led straight to either the first Windows NT release and ancestor of Windows 11, or the Win32s extension for WIndows 3.1. Thus a 1993 Win32S version of Freecell runs happily, but that want’s the end of the trail. Somewhere in the pre-release builds of Windows NT 3.1 would be the requisite binary, but there’s a snag. Early Windows NT 3.1 APIs were incompatible with later ones. This led through a lot of crashing binaries to a November 1992 version of the CD player app, that ran because it called a DLL which happens to still be present. The need for another DLL to emulate a CD drive speaks volumes about the progress of the PC world, back then they were the last word in storage but who’s got one now?

That’s the earliest official binary to run, but the story’s not quite over. Windows 11 may not have a VDM to run 16-bit apps, but there’s a WINE VDM for that. Behold, Reversi from Windows 1.01 in November 1985, in Windows 11. Your ancient software may yet be saved.