Windows 95 On An Apple Watch

April 30, 2016 by Jenny List 26 Comments

What happens if the slick user interface and tight iOS integration of your Apple Watch leave you wanting more? A real operating system, from the days when men were men and computers were big grey boxes!

[Nick Lee] solved this unexpected problem with his Watch by getting a working copy of Windows 95 to run on it. On paper it shouldn’t be at all difficult, with a 520 MHz ARM, 512 MB of RAM, and 8GB of storage you might think that it would eclipse the quick 486s and low-end Pentiums we ran ’95 on back in the day with ease. But of course, the ability to run aged Redmond operating systems on a Watch was probably not at the top of the Apple dev team’s feature list, so [Nick] had to jump through quite a few hoops to achieve it.

As you might expect, the ’95 installation isn’t running directly on the Watch. In the absence of an x86 processor his complex dev process involved getting the Bochs x86 emulator to compile for the Watch, and then giving that a ’95 image to boot. The result is comically slow, with a 1-hour boot time and a little motor attached to the Watch to vibrate it and stop it going to sleep. It’s not in any way a useful exercise, after all who’d really want to use ’95 on a Watch? Internet Explorer 3 and The Microsoft Network, how handy! But it’s one of those “because you can” exercises, and we applaud [Nick] for making it happen. If you want to give it a try, his Bochs-forWatchOS code is on Github.

The video below the break shows the process of booting the ’95 Watch, opening the Start Menu, and running one of the card games. One can almost feel the lengthening shadows outside as it goes.

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The Gerber Behind Gerber Files

April 29, 2016 by Jenny List 12 Comments

When we create a printed circuit board, the chances are these days that we’ll export it through our CAD package’s CAM tool, and send the resulting files to an inexpensive PCB fabrication house. A marvel of the modern age, bringing together computerised manufacturing, the Internet, and globalised trade to do something that would have been impossible only a few years ago without significant expenditure.

Those files we send off to China or wherever our boards are produced are called Gerber files. It’s a word that has become part of the currency of our art, “I’ll send them the Gerbers” trips off the tongue without our considering the word’s origin.

This morning we’re indebted to [drudrudru] for sending us a link to an EDN article that lifts the lid on who Gerber files are named for. [H. Joseph Gerber] was a prolific inventor whose work laid the ground for the CNC machines that provide us as hackers and makers with so many of the tools we take for granted. Just think: without his work we might not have our CNC routers, 3D printers, vinyl cutters and much more, and as for PCBs, we’d still be fiddling about with crêpe paper tape and acetate.

An Austrian Holocaust survivor who escaped to the USA in 1940, [Gerber] began his business with an elastic variable scale for performing numerical conversions that he patented while still an engineering student. The story goes that he used the elastic cord from his pyjamas to create the prototype. This was followed by an ever-more-sophisticated range of drafting, plotting, and digitizing tools, which led naturally into the then-emerging CNC field. It is probably safe to say that in the succeeding decades there has not been an area of manufacturing that has not been touched by his work.

So take a look at the article, read [Gerber]’s company history page, his Wikipedia page, raise a toast to the memory of a great engineer, and never, ever, spell “Gerber file” with a lower-case G.

The Minimin Aims To Be The Simplest Theremin

April 26, 2016 by Jenny List 5 Comments

Hackaday.io user [eagleisinsight] is a high-school hacker whose dreams of becoming a Theremin virtuoso were thwarted by the high cost of a commercial instrument. His response is the Minimin, an affordable Theremin design using a 555 and an ATMega328.

The 555 is configured as an astable oscillator running at about 5MHz and with a loop antenna attached to its timing capacitor. The parasitic capacitance of the musician’s hand against the antenna varies the frequency of the oscillation, as you would expect. In a classic Theremin the signal from the 555 would be mixed with the output from a fixed 5MHz oscillator and the sound would be generated from the difference between the two oscillators, but in [eagleisinsight]’s design the 555 clocks the ATMega328’s timer. The processor can thus read the oscillator frequency and use that value to control a waveform generator.

There is something missing from this Theremin: a second antenna for volume. For now a potentiometer does that job, but [eagleisinsight] is working on a MkII device to correct this omission, along with plans to replace the ATMega with an XMega processor whose DAC can produce a sine wave output and whose USB port can be used to enable the Minimin as a MIDI controller.

As you might expect, we’ve covered numerous Theremins over the years here on Hackaday. You can browse them all, but we’d like to draw your attention to a typical breadboard instrument using a soda can antenna, people using Theremins as Guitar Hero controllers, and Léon Theremin’s terpistone, a full-body instrument.

Pillaging The Wealth Of Information In A Datasheet

April 26, 2016 by Jenny List 33 Comments

It’s a fair assumption that the majority of Hackaday readers will be used to working with electronic components, they are the life blood of so many of the projects featured here. In a lot of cases those projects will feature very common components, those which have become commoditized through appearing across an enormous breadth of applications. We become familiar with those components through repeated use, and we build on that familiarity when we create our own circuits using them.

All manufacturers of electronic components will publish a datasheet for those components. A document containing all the pertinent information for a designer, including numerical parameters, graphs showing their characteristics, physical and thermal parameters, and some application information where needed. Back in the day they would be published as big thick books containing for example the sheets for all the components of a particular type from a manufacturer, but now they are available very conveniently online in PDF format from manufacturer or wholesaler websites.

Datasheets are a mine of information on the components they describe, but sometimes they can be rather impenetrable. There is a lot of information to be presented, indeed when the device in question is a highly integrated component such as a DSP or microprocessor the datasheet can resemble a medium-sized book. We’re sure that a lot of our readers will be completely at home in the pages of a datasheet, but equally it’s a concern that a section of the Hackaday audience will not be so familiar with them and will not receive their full benefit. Thus we’re going to examine and explain a datasheet in detail, and hopefully shed some light on what it contains.

The device whose datasheet we’ve chosen to put under the microscope is a transistor. The most basic building block of active semiconductor circuits, and the particular one we’ve chosen is a ubiquitous NPN signal transistor, the 2N3904. It’s been around for a very long time, having been introduced by Motorola in the 1960s, and has become the go-to device for a myriad circuits. You can buy 2N3904s made by a variety of manufacturers all of whom publish their own data sheets, but for the purposes of this article we’ll be using the PDF 2N3904 data sheet from ON Semiconductor, the spun-off former Motorola semiconductor division. You might find it worth your while opening this document in another window or printing it out for reference alongside the rest of this article.

Let’s take a look at all the knowledge enshrined in this datasheet, and the engineering eye you sometimes need to assign meaning to those numbers, diagrams, and formulas.

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Retrotechtacular: MONIAC

April 26, 2016 by Jenny List 26 Comments

There is an argument to be made that whichever hue of political buffoons ends up in Number 10 Downing Street, the White House, the Élysée Palace, or wherever the President, Prime Minister or despot lives in your country, eventually they will send the economy down the drain.

Fortunately, there is a machine for that. MONIAC is an analogue computer with water as its medium, designed to simulate a national economy for students. Invented in 1949 by the New Zealand economist [WIlliam Phillips], it is a large wooden board with a series of tanks interconnected by pipes and valves. Different sections of the economy are represented by the water tanks, and the pipes and valves model the flow of money between them. Spending is downhill gravitational water flow, while taxation is represented by a pump which returns money to the treasury at the top. It was designed to represent the British economy in the late 1940s as [Philips] was a student at the London School of Economics when he created it. Using the machine allowed students and economists for the first time to simulate the effects of real economic decisions in government, in real time.

So if you have a MONIAC, you can learn all about spectacularly mismanaging the economy, and then in a real sense flush the economy down the drain afterwards. The video below shows Cambridge University’s restored MONIAC in operation, and should explain the device’s workings in detail.
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Workshops For Timid Solderers

April 25, 2016 by Jenny List 35 Comments

As a hackspace member, it’s easy to fall into the belief that your own everyday skills are universal. Soldering for example. You’ve handled an iron since you were a youngster, the solder bends to your will as a matter of course, and since you see your fellow makers doing the same thing you might imagine that it’s a universal hackspace skill. Everyone can do it, can’t they?

Of course, they can’t. If you weren’t lucky enough to have a parent who tolerated your occasional propensity for acquiring burns on your fingers then you probably won’t have that innate experience with an iron. This extends to people you might expect to have those skills, indeed as an electronic engineering student a couple of decades ago your scribe was surprised to find that the ability to solder was her hotly tradeable skill, amazingly even a lot of EE students couldn’t solder.

So the ability to solder is not as universal as we might expect, and your hackspace will attract plenty of people for whom it is an as-yet-unknown art. What do you do about it? If you are Vancouver Hackspace, you run a workshop whose participants are introduced to soldering through building a simple AM radio. The kit itself is not too special, it looks like one of the Elenco educational kits, but it is what the workshop represents that is important. A hackspace lives or dies by how it shares its skills, and Vancouver’s workshop is a fantastic piece of community engagement. We’d like to see more spaces doing this kind of thing.

So, perhaps it’s time to put our money where our mouth is. How difficult would it be to run a hackspace soldering workshop for the uninitiated? Assuming your space is used to the mechanics of running events, the challenge is to find for each participant a soldering iron, some solder, and a radio or other kit without breaking the bank. An ideal budget from where this is being written in the UK would be £20 (about $29), into which a Chinese kit from AliBaba or similar and a cheap iron kit could be fitted. Some work to decipher the Chinese instructions with the help of an overseas student member and to write an English manual, and we’d be ready to go. If this comes together we’ll report back on whether the non-solderers of our hackspace successfully learned the craft.

We recently featured a similar educational initiative, a course at Swansea Hackspace teaching robotics through an Arduino robot. We would like to encourage this kind of thing, what is your hackspace doing in this line?

Fail Of The Week: Don’t Tie Those Serial Lines High

April 25, 2016 by Jenny List 56 Comments

Fail Of The Week is a long-running series here at Hackaday. Over the years we’ve been treated to a succession of entertaining, edifying, and sometimes downright sad cock-ups from many corners of the technological and maker world.

You might think that we Hackaday writers merely document the Fails of others, laughing at others’ misfortunes like that annoying kid at school. But no, we’re just as prone to failure as anyone else, and it is only fair that we eat our own dog food and tell the world about our ignominious disasters when they happen.

And so we come to my week. I had a test process to automate for my contract customer. A few outputs to drive some relays, a few inputs from buttons and microswitches. Reach for an Arduino Uno and a prototyping shield, divide the 14 digital I/O lines on the right into 7 outputs and 7 inputs. Route 7 to 13 into a ULN2003 to drive my relays, tie 0 to 6 high with a SIL resistor pack so I can trigger them with switches to ground. Job done, and indeed this is substantially the hardware the test rig ended up using.

So off to the Arduino IDE to write my sketch. No rocket science involved, a fairly simple set of inputs, outputs, and timers. Upload it to the Arduino, and the LED on pin 13 flashes as expected. Go for a well-deserved lunch as a successful and competent engineer who can whip up a test rig in no time.

Back at the bench refreshed by the finest British pub grub, I started up the PC, plugged the shield into the Arduino, and applied the power. My sketch worked. But wait! There’s a slight bug! Back to the IDE, change a line or two and upload the sketch.

And here comes my fail. The sketch wouldn’t upload, the IDE reported a COM port error. “Damn’ Windows 10 handling of USB serial ports”, I thought, as I’m not a habitual Windows user on my own machines. Then followed something I’ve not done for quite a while; diving into the Windows control panel to chase the problem. Because it had to be a Windows problem, right?

The seasoned Arduinisti among you probably spotted my fail four paragraphs ago. We all know that pins 0 and 1 on an Arduino are shared with the serial port, but who gives it a second thought? I guess I’d always had the good fortune to drive those pins from lines which didn’t enforce a logic state, and had never ended up tying them high. Hold them to a logic 1, and the Arduino can’t do its serial thing so sketches stay firmly in the IDE.

I could have popped the shield off every time I wanted to upload a new sketch, but since in the event I didn’t need all those inputs I just lifted the links tying those pins high and shifted the other inputs up the line. And went home that evening a slightly less competent engineer whose ability to whip up a test rig in no time was a bit tarnished. Ho hum, at least the revised sketch worked and the test rig did its job exactly as it should.

So that’s my Fail Of The Week. What’s yours?

Header image: pighixxx.com, CC-BY-ND via MarkusJenkins

Fail of the Week is a Hackaday column which celebrates failure as a learning tool. Help keep the fun rolling by writing about your own failures and sending us a link to the story — or sending in links to fail write ups you find in your Internet travels.