Info Sought On A Forgotten Cuban Radio

March 21, 2023 by Jenny List 11 Comments

Some of the daily normalities of life in the Cold War seem a little surreal from our perspective in 2023, when nuclear bombers no longer come in to land just down the road and you can head off to Poland or Czechia on a whim. Radio amateurs were one of the few groups of civilians whose activities crossed the geopolitical divide, and even though an operator on the other side from ours couldn’t buy a shiny Japanese radio, their homebrew skills matched anything we could do with our Western soldering irons.

[Bill Meara N2CQR] is particularly interested in one line of Cold War-era Communist homebrew radios, the tube-based Cuban “Islander” and its solid-state “Jaguey” sibling. It’s a homebrew double-sideband transceiver design built using readily-available Soviet TV parts, and though he’s published what he can find, he’s on the lookout for more info about these interesting rigs.

The mechanics of a DSB transceiver are simple enough, in that an oscillator and balanced mixer can serve as both modulator and as direct conversion receiver. The fuzzy black and white photographs give frustratingly little detail, but we’re impressed by the quality of what we can see. We have readers all over the world (including we hope, some in Cuba), so perhaps if you know something about these radios you can give Joe a hand. It’s a design that deserves to be appreciated.

For more epic Cold War hackery on the Communist side, read our colleague [Voja Antonic]’s story of his personal computer odyssey.

Vinyl Sales Ran Circles Around CDs In 2022

March 21, 2023 by Kristina Panos 108 Comments

How do you take your music these days? For those in Camp Tangible, it seems our ranks are certainly growing, and in the analog direction. For the first time since 1987, vinyl record sales have outperformed CD sales in the US, according to a new report. The CD, which saved us all from the cassette, was a digital revolution in music. But for some, the love was lost somewhere among the ones and zeroes.

Those who prefer pure analog troughs of sound cut into wax have never given up on vinyl, and the real ones probably gobbled up a bunch of it in the 90s when everybody was CD-crazy. But mind you these aren’t used vinyl sales we’re talking about, which means that enough new vinyl has to have been readily available for purchase for quite some time now. Although it doesn’t really seem like that long, new vinyl’s been back for almost 20 years — and according to the report, 2022 was the 16th consecutive year of growth for record sales.

So Why Vinyl?

Nostalgia ain’t what it used to be, but there was a time in my 1980s childhood when vinyl was all this scribe had to listen to. I have historically been a bit slow to adopt new music formats — I didn’t have a CD player until 1998, and it was given to me for my birthday. I was excited to get the thing, mind you, especially since it had 10 seconds of anti-skip protection (which of course was a huge concern with portable CD players).

But CDs are way different from records. Sure, they’re both round, but the similarities sort of end there. For one thing, the artwork is disappointingly small compared to vinyl. And the whole gatefold album cover thing isn’t really possible with a CD, unless you forego the jewel case and release it in a chintzy little cardboard jacket. But then people will have this one disc that’s four times thinner than the rest and it throws everything off in the collection.

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The Rise And (Eventual) Fall Of The SIM Card

March 20, 2023 by Tom Nardi 109 Comments

There are few devices that better exemplify the breakneck pace of modern technical advancement than the mobile phone. In the span of just a decade, we went from flip phones and polyphonic ringtones to full-fledged mobile computers with quad-core processors and gigabytes of memory.

While rapid advancements in computational power are of course nothing new, the evolution of mobile devices is something altogether different. The Razr V3 of 2003 and the Nexus 5 of 2013 are so vastly different that it’s hard to reconcile the fact they were (at least ostensibly) designed to serve the same purpose — with everything from their basic physical layout to the way the user interacts with them having undergone dramatic changes in the intervening years. Even the network technology they use to facilitate voice and data communication are different.

Yet, there’s at least one component they share: the lowly SIM card. In fact, if you don’t mind trimming a bit of unnecessary plastic away, you could pull the SIM out of the Razr and slap it into the Nexus 5 without a problem. It doesn’t matter that the latter phone wasn’t even a twinkling in Google’s eye when the card was made, the nature of the SIM card means compatibility is a given.

Indeed there’s every reason to believe that very same card, now 20 years old, could be installed in any number of phones on the market today. Although, once again, some minor surgery would be required to pare it down to size.

Such is the beauty of the SIM, or Subscriber Identity Module. It allows you to easily transfer your cellular service from one phone to another, with little regard to the age or manufacturer of the device, and generally without even having to inform your carrier of the swap. It’s a simple concept that has served us well for almost as long as cellular telephones have existed, and separates the phone from the phone contract.

So naturally, there’s mounting pressure in the industry to screw it up.

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The X Macro: A Historic Preprocessor Hack

March 16, 2023 by Al Williams 45 Comments

If we told you that a C preprocessor hack dated back to 1968, you’d be within your rights to remind us that C didn’t exist in 1968. However, assemblers with preprocessors did, and where there is a preprocessor, there is an opportunity to do clever things. One of those things is the so-called X macro, which saw a lot of use in DEC System 10 code but probably dates back even earlier. You can still use it today if you like, even though there are, of course, other arguably better ways to get the same result. However, the X macro can be very efficient, and you may well run into it in some code, too.

Background

Preprocessing used to be a staple of programming. The idea is that code is manipulated purely at the text level before it is compiled. These days, languages with a preprocessor usually handle it as part of the compiler, but you can also use an external preprocessor like m4 for more sophisticated uses.

Modern languages tend to provide other ways to accomplish many of the tasks handled by the preprocessor. For example, if you have a constant you want to set at compile time, you could say:

int X = 32;
y = X;

But then you’ve created a real variable along with the overhead that might entail. A smart compiler might optimize it away for you, but you can be sure by writing:

#define X 32
y = X;

A modern compiler would prefer you to write:

const int X=32;
y = X;

But there are still some common uses for macros, like including header files. You can also make more sophisticated macros with arguments so you don’t incur a function call penalty, although modern usage would be to mark those functions as inline.

The Problem

Which brings us to the X macro. With all great hacks, there is first a problem to solve. Imagine you have a bunch of electronic parts you want to deal with in your code. You don’t want a database, and you don’t want to carry a bunch of strings around, so you define an enumerated type:

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Review: XHDATA D-219 Short Wave Radio Receiver

March 15, 2023 by Jenny List 112 Comments

As any radio amateur will tell you, the world of radio abounds with exciting possibilities. Probably the simplest pursuit of them all is that of the SWL, or short wave listener, who scours the airwaves in search of interesting stations. SWLs will often have fully-featured setups with high-end general-coverage communications receivers and tuned antenna arrays, but it can start with the cheapest of radios at its bottom end. Such a radio is the subject of this review, the XHDATA D-219 is a miniature portable receiver that costs under ten dollars, yet is currently the talk of the town in SWL circles. This interest is in no small amount due to its being an especially low-price way to get your hands on a shortwave radio using one of the SIlicon Labs integrated software-defind radio receiver chips. We don’t often review a consumer radio here at Hackaday, but with an avid eye for unexpected gems at the cheaper end of the market this one’s worth a second look.

What Do You Get For Your Tenner?

A picture of the radio on my bench — This form factor is very typical for cheap “world band” radios.

I ordered my D-219 from the XHDATA website, spending about £10 including the postage from China. The usual wait ensued before the package landed on my doormat, and inside was the radio in its box with an instruction leaflet. It’s a small unit about 135 mm x 75 mm x 30 mm, and it follows closely the form factor of other similar radios.

On the top is the extensible antenna with an on-off switch and sockets for headphone and 5 V power, on the side are side-on knobs for tuning and volume, while on the front is the speaker and old-style multi-band tuning display.

On the back is a flip-up stand and a hatch for a pair of AA cells. There’s a band switch covering AM, nine different shortwave bands from 4.75 MHz to 22 MHz, the east Asian FM band from 64 MHz to 87 MHz, and the international FM band from 87 MHz to 108 MHz. The tuning indicator is very old-school, a vertical bar that moves across a frequency scale with the tuning knob. Continue reading “Review: XHDATA D-219 Short Wave Radio Receiver” →

PCIe For Hackers: The Diffpair Prelude

March 14, 2023 by Arya Voronova 35 Comments

PCIe, also known as PCI-Express, is a highly powerful interface. So let’s see what it takes to hack on something that powerful. PCIe is be a bit intimidating at first, however it is reasonably simple to start building PCIe stuff, and the interface is quite resilient for hobbyist-level technology. There will come a time when we want to use a PCIe chip in our designs, or perhaps, make use of the PCIe connection available on a certain Compute Module, and it’s good to make sure that we’re ready for that.

PCIe is everywhere now. Every modern computer has a bunch of PCIe devices performing crucial functions, and even iPhones use PCIe internally to connect the CPU with the flash and WiFi chips. You can get all kinds of PCIe devices: Ethernet controllers, high-throughput WiFi cards, graphics, and all the cheap NVMe drives that gladly provide you with heaps of storage when connected over PCIe. If you’re hacking on a laptop or a single-board computer and you’d like to add a PCIe device, you can get some PCIe from one of the PCIe-carrying sockets, or just tap into an existing PCIe link if there’s no socket to connect to. It’s been two decades since we’ve started getting PCIe devices – now, PCIe is on its 5.0 revision, and it’s clear that it’s here to stay.

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The Curious Etymology Of The Elements

March 13, 2023 by Jenny List 34 Comments

It’s not often that the worlds of lexicography and technology collide, but in a video by the etymologist [RobWords] we may have found a rare example. In a fascinating 16-minute video he takes us through the origins of the names you’ll find in the periodic table. Here’s a word video you don’t have to be on the staff of a dictionary to appreciate!

Etymology is a fascinating study, in which the scholar must disentangle folk etymologies and mistaken homophones to find the true root of a word. Fortunately in the case of most elements they bear a name bestowed on them by the scientists who discovered them, so their etymologies are rarely in dispute.

The etymologies split neatly into categories, with among them such distinctions as Latin or Greek descriptions, places including the Swedish village of Ytterby which has more elements named after it than anywhere else, elements named for mythological figures, and those named for people.

He artfully skates over the distinction between aluminium and a curiously similar metal the Americans call aluminum, because etymologists are used to deflecting controversy when language differences colour, or even color, people’s emotions. Thank you, Noah Webster!

It’s an entertaining diversion for anyone with a love of both science and of language, and should remind us that the study of language has just as much scientific rigour in its research as any of those elements.

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