This Computer Is Definitely Not A Toy

September 30, 2022 by Jenny List 6 Comments

If you’ve ever eyed up a kids laptop and wondered whether it could take an upgrade with a single board computer, you’re not alone. [Labz] have taken a couple of Brazilian Max Steel toy computers from a decade or more ago, and made them into usable if unconventional portable computers (Brazilian Portuguese, but YouTube’s subtitle translation is your friend).

The computers are similar to the ones you may be familiar with from the likes of VTech, a QWERTY keyboard and fairly conventional form factor but with a tiny monochrome LCD and a few built-in games. In the video below the break we see both the laptop and desktop variants butchered with a rotary tool to receive new larger screens, with the laptop getting a Raspberry Pi and the desktop getting a small form factor PC. The laptop needed a 3D printed extension to make extra space, while the desktop received a PCI Express extension cable for a video card. Finally, an Arduino took care of the keyboard.

The cherry on the cake for this video comes at the end, when they find the now-grown-up kid from the original advert. Meanwhile, kids computers have featured here before a few times.

Continue reading “This Computer Is Definitely Not A Toy” →

Hackaday Prize 2022: An Old (and Distinguished) Camera Learns New Tricks

September 29, 2022 by Jenny List 4 Comments

In the 1950s the major Hollywood studios needed impressive cinematic technologies for their epic movies, to both see off the threat from television, and to differentiate themselves from their competitors. For most of them this meant larger screens and thus larger frame film, and for Paramount, this meant VistaVision. [Steve Switaj] is working on one of the original VistaVision cameras made for the studio in the 1950s, and shares with us some of the history and the work required to update its electronics for the 2020s.

VistaVision itself had a relatively short life, but the cameras were retrieved from storage in the 1980s because their properties made them suitable for special effects work. This mostly analog upgrade hardware on this one had died, so he set to and designed a PIC based replacement. Unexpectedly it uses through-hole components for ease of replacement using sockets, and it replaces a mechanical brake fitted to the 1980s upgrade with an electronic pull back on the appropriate reel motor.

The whole thing makes for an interesting delve into some movie history, and also a chance to see some tech most of us will never encounter even if we have a thing for movie cameras.

IBM Made A MIPS Laptop. Will It Make You WinCE?

September 29, 2022 by Jenny List 26 Comments

We’re used to our laptop computers here in 2022 being ultra-portable, super-powerful, and with impressively long battery lives. It’s easy to forget then that there was a time when from those three features the laptop user could usually expect only one of them in their device. Powerful laptops were the size of paving slabs and had battery lives measured in minutes, while anything small usually had disappointing performance or yet again a minuscule power budget.

In the late 1990s manufacturers saw a way out of this in Microsoft’s Windows CE, which would run on modest hardware without drinking power. Several devices made it to market, among them one from IBM which [OldVCR] has taken a look at. It makes for an interesting trip down one of those dead-end side roads in computing history.

In the box bought through an online auction is a tiny laptop that screams IBM, we’d identify it as a ThinkPad immediately if it wasn’t for that brand being absent. This is an IBM WorkPad, a baby sibling of the ThinkPad line intended as a companion device. This one has a reduced spec screen and an NEC MIPS processor, with Windows CE on a ROM SODIMM accessible through a cover on the underside. For us in 2022 MIPS processors based on the open-sourced MIPS ISA are found in low-end webcams and routers, but back then it was a real contender. The article goes into some detail on the various families of chips from that time, which is worth a read in itself.

We remember these laptops, and while the IBM one was unaffordable there was a COMPAQ competitor which did seem tempting for on-the-road work. They failed to make an impact due to being marketed as a high-end executive’s toy rather than a mass-market computer, and they were seen off as “real” laptops became more affordable. A second-hand HP Omnibook 800 did the ultra-portable job on this bench instead.

The industry had various attempts at cracking this market, most notably with the netbooks which appeared a few years after the WorkPad was produced. It was left to Google to reinvent the ultra-portable non-Intel laptop as an internet appliance with their Chromebooks before they would become a mass-market device, but the WorkPad remains a tantalizing glimpse of what might have been.

Windows CE occasionally makes an appearance here, and yes, it runs DOOM.

Current Loop Extends Wired Microphones Past 1 Km

September 27, 2022 by Jenny List 22 Comments

A problem which beset early telephone engineers was that as the length of their lines increased, so did the distortion of whatever signal they wanted to transmit. This was corrected once they had gained an understanding of the capacitance and inductance of a long cable. The same effects hamper attempts to place microphones on long lines, and [Leo’s Bag of Tricks] has a solution for doing that using Cat5 cable. The application is audio surveillance, but we think the technique is useful enough to have application elsewhere.

The solution which you can see in the video below the break will be familiar to teletype aficionados who have encountered current loops, in that it creates an analogue current loop. There is a standing DC current in the tens of miliamperes, and this has the audio imposed upon it by an amplifier and shunt transistor. The audio can be easily retrieved using a pair of small transformers, leading to efficient transfer over as much of a kilometer of Cat5 cable. We’re guessing it’s not quite audiophile quality, but it’s useful to know that a current loop can be just as useful in the analogue domain as in the digital. If the subject interests you, we did a feature on them a few years ago.

Continue reading “Current Loop Extends Wired Microphones Past 1 Km” →

Probably The Simplest Radiation Detector You Already Own

September 26, 2022 by Jenny List 78 Comments

Over the years we’ve featured quite a few radiatioactivity detectors, which usually include a Geiger-Muller tube, or perhaps a large-area photodiode. But in the event of radiation exposure from a nuclear attack, how does the man in the street gauge the exposure without owning a dedicated instrument? This was a question of note at the height of the Cold War, and it’s one that [Dr. Marshall Brucer] answered in a 1962 paper entitled “When Do You Leave A Fallout Shelter“. The full paper is behind a paywall but the part we’re interested in is on the freely available first page.

Dr. Brucer‘s detector is simplicity itself, and it relies on the erosion of a static electric charge by radiation. Should you rub a plastic comb in your hair it will accumulate enough charge to pick up a small piece of paper, and under normal background radiation the charge will ebb away such that it will drop the piece of paper after about 15 seconds. His calculation is that once the field reaches around 10 roentgens per hour it will be enough to erase the charge and drop the paper immediately. There’s a comtemporary newspaper report (Page 7, just to the left of the large advertisment) which tells the reader that since the exposure limit is 100 roentgens (one sievert), this test failing indicates that they have nine hours to create a better shelter. For obvious reasons we can’t test this at the Hackaday bench, but those of us who remember the days when such topics were a real concern will be searching for a handy comb anyway.

Thanks [Victor Matthew] for the tip.

An All-In-One Serial Printer Playground

September 22, 2022 by Jenny List 10 Comments

One of the peripherals of most desire for a microcomputer-obsessed youth in the 1980s was a printer, probably a dot-matrix device. In the decades since, printers have passed into being almost a piece of discardable junk as cheap inkjets can be found in any garage sale. That’s not to say that there’s not plenty of fun to be had hacking older types though, and there are plenty of small thermal printers out there to play with. [Tanmoydutta] has provided a platform that may help, in the form of an ESP32-C3-based serial printer controller.

On board is a level shifter for the 5 volt printer electronics and all the appropriate connectors for the printer, as well as the ESP and onboard USB interface. It’s a networked print server, but one which is entirely and completely hackable. We think the printer in question is this one sold by Adafruit.

So this board makes easier a whole host of printer-related projects, and should you try it you will no doubt finding yourself ankle-deep in little curly pieces of paper. This printer’s not the only one in town though, don’t forget the cheap Bluetooth printers!

Know Audio: Stereo

September 21, 2022 by Jenny List 16 Comments

In our occasional series charting audio and Hi-Fi technology we have passed at a technical level the main components of a home audio set-up. In our last outing when we looked at cabling we left you with a promise of covering instrumentation, but now it’s time instead for a short digression into another topic: stereo. It’s a word so tied-in with Hi-Fi that “a stereo” is an alternative word for almost any music system, but what does it really mean? What makes a stereo recording, and how does it arrive at your ears?

From West London Trains, To 3D Audio

A steam train passing through a station, from a distance in black and white — The driver of this Great Western Railway train had no idea that he was making audio history.

As most of you will know, a mono recording uses a single microphone and a single channel while a stereo one uses two microphones recording simultaneously a left and right channel. These are then played back through a pair of speakers, and the result is a sense of spatial field for the listener. Instruments appear to come from their relative positions when recorded, and the sense of being in the performance is enhanced.

Stereo recording as we know it was first perfected as one of the many inventions credited to Alan Blumlein, then working for EMI in London. We have one of his stereo demonstration films in “Trains at Hayes“, filmed from the EMI laboratories overlooking the Great Western Railway, and featuring a series of steam-hauled trains crossing the field of view with a corresponding stereo sound field. His work laid down the fundamentals of stereo recording, including microphone configurations and what would become the standard for stereo audio recording on disk with the channels on the opposite sides of a 45 degree groove. Continue reading “Know Audio: Stereo” →