Retro tech is cool. Retro tech that works is even cooler. When we can see technology working, hold it in our hand, and use it as though we’ve been transported back in time; that’s when we feel truly connected to history. To help others create small time anomalies of their own, [Dmitrii Eliuseev] put together a quick how-to for creating your own Advanced Mobile Phone System (AMPS) network which can bring some of the classic cellular heroes of yesterday back to life.
Few readers will be surprised to learn that this project is built on software defined radio (SDR) and the Osmocom-Analog project, which we’ve seen before used to create a more modern GSM network at EMF Camp. Past projects were based on LimeSDR, but here we see that USRP is just as easily supported. [Dmitrii] also provides a brief history of AMPS, including some of the reasons it persisted so long, until 2007! The system features a very large coverage area with relatively few towers and has surprisingly good audio quality. He also discusses its disadvantages, primarily that anyone with a scanner and the right know-how could tune to the analog voice frequencies and eavesdrop on conversations. That alone, we must admit, is a pretty strong case for retiring the system.
The article does note that there may be legal issues with running your own cell network, so be sure to check your local regulations. He also points out that AMPS is robust enough to work short-range with a dummy load instead of an antenna, which may help avoid regulatory issues. That being said, SDRs have opened up so many possibilities for what hackers can do with old wireless protocols. You can even go back to the time when pagers were king. Alternatively, if wired is more your thing, we can always recommend becoming your own dial-up ISP.
I often think we — or maybe the people who control our money — lack the audacity to take on really big projects. It is hard to imagine laying the transatlantic cable for the first time today, for example. When I want a good example of this effect, I usually say something like: “Can you imagine going to a boardroom of a major company today and saying, ‘We plan to run wire to every house and business in the world and connect them all together.'” Yet that’s what the phone company did. But it turns out, running copper wire everywhere was only one major challenge for the phone company. The other was printing phone directories. In today’s world, it is easy to imagine a computer system that keeps track of all the phone numbers that can spit out a printed version for duplication. But that’s a relatively recent innovation. How did big city phonebooks work before the advent of the computer?
Turns out, the Saturday Evening Post talked about how it all worked in a 1954 article. We aren’t sure there weren’t some computerized records by 1954, but the whole process was still largely manual. By that year, an estimated 60,000,000 directories went out each year in the United States alone. Some of these were small, but the Chicago directory — not including suburban directories — had over 2,100 pages. In New York City, the solution was to print a separate book for each borough. Even then. the Manhattan book was three inches thick and projected to grow to five inches by 1975.
Continue reading “Technical Audacity And The Phone Book”
Today the Nokia brand can be found on a range of well-screwed-together Androind phones and a few feature phones, but as older readers will remember that before their descent into corporate chaos and the Windows Phone wilderness, there was once a time when the Finnish manufacturer dominated the mobile phone landscape and produced some of the most innovative and creative handset designs ever created. It’s for some of these that [Michael Fitzmayer] has done some work providing tools revive the devices from an unfortunate bricking.
The N-Gage was the phone giant’s attempt to produce a handset that doubled as a handheld game console, and though it was a commercial failure at the time it has retained a following among enthusiasts. The flaw comes as its Symbian operating system fills its user partition, at which point the infamous “White Screen Of Death” occurs as the device can no longer reboot. Rewriting the flash chip used to be handled by Nokia service tools, but these can no longer be found. His fix substitutes a “Blue pill” STMF103-based dev board that connects to the Nokia FBus serial port and does its job. It’s possible that it could be used on other Symbian devices, but for now it’s only been tested on the N-Gages.
It’s easy to forget when a smartphone is defined by iOS and Android, that Symbian gave us a smartphone experience for the previous decade. For those of us who still pine for their miniaturised Carl Zeiss Tessar cameras and candybar form factors, it’s good to see them receiving some love.
Thanks [Razvan] for the tip.
The modern consumer is not overly concerned with their phone conversations being monitored. For one thing, Google and Amazon have done a tremendous job of conditioning them to believe that electronic gadgets listening to their every word isn’t just acceptable, but a near necessity in the 21st century. After all, if there was a better way to turn on the kitchen light than having a recording of your voice uploaded to Amazon so they can run it through their speech analysis software, somebody would have surely thought of it by now.
But perhaps more importantly, there’s a general understanding that the nature of telephony has changed to the point that few outside of three letter agencies can realistically intercept a phone call. Sure we’ve seen the occasional spoofed GSM network pop up at hacker cons, and there’s a troubling number of StingRays floating around out there, but it’s still a far cry from how things were back when folks still used phones that plugged into the wall. In those days, the neighborhood creep needed little more than a pair of wire strippers to listen in on your every word.
Which is precisely why products like the TA-1356 Tap Trapper were made. It was advertised as being able to scan your home’s phone line to alert you when somebody else might be listening in, whether it was a tape recorder spliced in on the pole or somebody in another room lifting the handset. You just had to clip it onto the phone distribution panel and feed it a fresh battery once and awhile.
If the red light came on, you’d know something had changed since the Tap Trapper was installed and calibrated. But how did this futuristic defender of communications privacy work? Let’s open it up and take a look.
Continue reading “Teardown: Tap Trapper”
Do you remember when smartphones had real physical keyboards? Working the command line on some remote machine over SSH was a breeze, and you could even knock out a few lines of code if you were so inclined. But these days you’ve either got to lug around an external keyboard, or suffer through pecking out a few words per minute on a piece of glass. Doesn’t sound much like progress to us.
By the looks of it, [James Williams] doesn’t think so either. He’s designed a physical keyboard add-on that snaps onto the back of the PinePhone to deliver a proper, albeit condensed, typing experience. This is no repurposed BlackBerry board either; he’s created a custom mechanical keyboard that manages to fold into an incredibly small size thanks to resin printed keycaps and Kailh low profile switches. Other than the hand-drawn legends, it’s probably not a stretch to say this is a better keyboard than what many people have on their actual computers.
In addition to the 3D printed frame and Kailh switches, there’s also an Arduino Pro Micro onboard to communicate with the phone. Rather than use USB, the keyboard is wired to the I2C accessory port on the rear of the PinePhone. It sounds like [James] needs a little more time to polish his QMK build before its ready to release, so you might want to wait a bit before you start printing off your own copy of the parts.
Those following along with the development of the PinePhone know there’s supposedly an official keyboard accessory in the works, but who wants to wait when we’re so close to mobile Linux nirvana? Besides, we doubt it will be nearly as pleasant to type on as the board [James] has put together.
Phones used to be phones. Then we got cordless phones which were part phone and part radio. Then we got cell phones. But with smartphones, we have a phone that is both a radio and a computer. Tiny battery operated computers are typically a bit anemic, but as technology marches forward, those tiny computers grew to the point that they outpace desktop machines from a few years ago. That means more and more phones are incorporating technology we used to reserve for desktop computers and servers. Case in point: Xiaomi now has a smartphone that sports a RAM drive. Is this really necessary?
While people like to say you can never be too rich or too thin, memory can never be too big or too fast. Unfortunately, that’s always been a zero-sum game. Fast memory tends to be lower-density while large capacity memory tends to be slower. The fastest common memory is static RAM, but that requires a lot of area on a chip per bit and also consumes a lot of power. That’s why most computers and devices use dynamic RAM for main storage. Since each bit is little more than a capacitor, the density is good and power requirements are reasonable. The downside? Internally, the memory needs a rewrite when read or periodically before the tiny capacitors discharge.
Although dynamic RAM density is high, flash memory still serves as the “disk drive” for most phones. It is dense, cheap, and — unlike RAM — holds data with no power. The downside is the interface to it is cumbersome and relatively slow despite new standards to improve throughput. There’s virtually no way the type of flash memory used in a typical phone will ever match the access speeds you can get with RAM.
So, are our phones held back by the speed of the flash? Are they calling out for a new paradigm that taps the speed of RAM whenever possible? Let’s unpack this issue.
Continue reading “Does Your Phone Need A RAM Drive?”
The Android phone that you carry in your pocket is basically a small computer running Linux. So why is it so hard to get to a usable Linux environment on your phone? If you could run Linux, you could turn your cell phone into an ultra-portable laptop replacement.
Of course, the obvious approach is just to root the phone and clean-slate install a Linux distribution on it. That’s pretty extreme and, honestly, you would probably lose a lot of phone function unless you go with a Linux-specific phone like the PinePhone. However, using an installer called AnLinux, along with a terminal program and a VNC client, you can get a workable setup without nuking your phone’s OS, or even having root access. Let’s see what we can do. Continue reading “Linux Fu: The Linux Android Convergence”