Rabbit Sighted In The Wild

April 13, 2024 by Jenny List 21 Comments

Here at Hackaday we’re suckers for old abandoned technologies, the more obscure the better. The history of the telephone has plenty to capture our attention, and it’s from that arena that something recently floated past our timeline. [IanVisits] reports a sighting of a Rabbit in a London Underground station. The bunny in question definitely isn’t hopping though, it’s been dead for more than three decades. It’s a base station for a failed digital mobile phone system.

We’ve had a look in the past at CT2, the system this Rabbit base station once formed part of. It was an attempt to make an inexpensive phone system by having the handsets work with fixed base stations rather than move from cell to cell. It was one of the first public digital mobile phone systems, but the convenience of a phone that could both receive calls and make them anywhere without having to find a base station meant that GSM phones took their market.

The one in Seven Sisters tube station is a bit grubby looking, but it’s not the only survivor out there in the field. We have to admit to being curious as to whether it’s still powered on even though its backhaul will be disconnected, as in our experience it’s not uncommon for old infrastructure to be left plugged into the wall for decades, unheeded. Does anyone fancy sniffing for it with a Flipper Zero?

A Dial Phone SIPs Asterisk

March 24, 2024 by Jenny List 8 Comments

An endless source of amusement for those of advancing years can come from handing a rotary phone to a teenager and asking them to dial a number with it. It’s rare for them to be stumped by a piece of technology, after all. [Mnutt]’s 4-year-old son had no such problems when he saw rotary phones at an art exhibition, so what was a parent to do but wire the phone to an Asterisk PBX with shortcut numbers for calls to family and such essential services as a joke line, MTA status, or even a K-pop song.

It’s possible to hook up a pulse dial phone with a SLIC module and a microcontroller, but in this case, a Grandstream SIP box did the trick. These are all-in-one devices that implement a SIP client with a physical connection, and older ones will talk to pulse dialers as well as the more usual tone dialing phones. The phone in question is a vintage American model. Writing this from Europe we were surprised to find a little simpler inside than its transatlantic counterparts of the same era.

An Asterisk install on a Raspberry Pi completed the project, and thus it became a matter of software configuration. It’s a useful run-through for Asterisk dilettantes, even if you haven’t got a 4-year-old. Perhaps you have an old payphone or two!

The FPC adapter shown soldered between the BGA chip and the phone's mainboard, with the phone shown to have successfully booted, displaying an unlock prompt on the screen

IPhone 6S NVMe Chip Tapped Using A Flexible PCB

March 3, 2024 by Arya Voronova 3 Comments

Psst! Hey kid! Want to reverse-engineer some iPhones? Well, did you know that modern iPhones use PCIe, and specifically, NVMe for their storage chips? And if so, have you ever wondered about sniffing those communications? Wonder no more, as this research team shows us how they tapped them with a flexible printed circuit (FPC) BGA interposer on an iPhone 6S, the first iPhone to use NVMe-based storage.

The research was done by [Mohamed Amine Khelif], [Jordane Lorandel], and [Olivier Romain], and it shows us all the nitty-gritty of getting at the NVMe chip — provided you’re comfortable with BGA soldering and perhaps got an X-ray machine handy to check for mistakes. As research progressed, they’ve successfully removed the memory chip dealing with underfill and BGA soldering nuances, and added an 1:1 interposer FR4 board for the first test, that proved to be successful. Then, they made an FPC interposer that also taps into the signal and data pins, soldered the flash chip on top of it, successfully booted the iPhone 6S, and scoped the data lines for us to see.

This is looking like the beginnings of a fun platform for iOS or iPhone hardware reverse-engineering, and we’re waiting for further results with bated breath! This team of researchers in particular is prolific, having already been poking at things like MITM attacks on I2C and PCIe, as well as IoT device and smartphone security research. We haven’t seen any Eagle CAD files for the interposers published, but thankfully, most of the know-how is about the soldering technique, and the paper describes plenty. Want to learn more about these chips? We’ve covered a different hacker taking a stab at reusing them before. Or perhaps, would you like to know NVMe in more depth? If so, we’ve got just the article for you.

We thank [FedX] for sharing this with us on the Hackaday Discord server!

The End Of Landlines?

February 8, 2024 by Al Williams 94 Comments

Imagine if, somehow, telephones of all kinds had not been invented. Then, this morning, someone entered a big corporation board room and said, “We’d like to string copper wire to every home and business in the country. We’ll get easements and put the wires on poles mostly. But some of them will go underground where we will dig tunnels. Oh, and we will do it in other countries, too, and connect them with giant undersea cables!” We imagine that executive would be looking for a job by lunchtime. Yet, we built that exact system and with far less tech than we have today. But cell phones have replaced the need for copper wire to go everywhere, and now AT&T is petitioning California to let them off the hook — no pun intended — for servicing landlines.

The use of cell phones has dramatically decreased the demand for the POTS or plain old telephone service. Even if you have wired service now, it is more likely fiber optic or, at least, an IP-based network connection that can handle VOIP.

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Your 1983 Video Phone Is Finally Ready

February 7, 2024 by Al Williams 8 Comments

If you read Byte magazine in 1983, you might have expected that, by now, you’d be able to buy the red phone with the video screen built-in. You know, like the one that appears on the cover of the magazine. Of course, you can’t. But that didn’t stop former Hackaday luminary [Cameron] from duplicating the mythical device, if not precisely, then in spirit. Check it out in the video, below.

While the original Byte article was about VideoTex, [Cameron] built a device with even more capability you couldn’t have dreamed of in 1983. What’s more, the build was simple. He started with an old analog phone and a tiny Android phone. A 3D-printed faceplate lets the fake phone serve as a sort of dock for the cellular device.

That’s not all, though. Using the guts of a Bluetooth headset enables the fake phone’s handset. Now you can access the web — sort of a super Videotex system. You can even make video calls.

There isn’t a lot of detail about the build, but you probably don’t need it. This is more of an art project, and your analog phone, cell phone, and Bluetooth gizmo will probably be different anyway.

Everyone always wanted a video phone, and while we sort of have them now, it doesn’t quite seem the same as we imagined them. We wish [Cameron] would put an app on the phone to simulate a rotary dial and maybe even act as an answering machine.

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Schematics, For A Modern Flagship Phone

February 7, 2024 by Jenny List 36 Comments

The mobile phone is an expensive and often surprisingly fragile device, whose manufacturers are notorious for making them as difficult to repair as possible. Glued-together cases and unreplaceable batteries abound, and technical information is non-existent. But amongst all that there’s one manufacturer with a different approach — Fairphone. Case in point, they’ve released the full service guide including schematics for their flagship Fairphone 5.

Fairphone’s selling point is the repairability and internal accessibility of their products and of course they’ve made hay with this as a marketing opportunity. But aside from that, it’s a fascinating chance to look in-depth at a modern smartphone from the inside out. We see the next-level PCB layout and how everything is so neatly packed into the minimum space, all without resorting to a heat gun.

It’s great to have another hackable phone, and fair play to Fairphone for releasing all this stuff, but perhaps the most interesting part from where we’re sitting is how and where this phone is being sold. There have been hackable phones before, for many the Pinephone will spring to mind, but they have always been sold to an audience who buy to hack. Here in Europe where this is being written, the Fairphone is being sold as a consumer device. It won’t shake Apple or Samsung from their perches, but for a hackable device to be so generally available to those who wish to do things with it can never be a bad thing.

We took a quick look at Fairphone back in 2015, when they launched.

A Crossbar Telephone Switch Explained

February 4, 2024 by Jenny List 14 Comments

There’s an old adage about waiting hours for a bus only for two to appear at once, and for Hackaday this month we’re pleased to have seen this in a run of analogue telephone projects. Latest among them is the video below the break from [Wim de Kinderen], who is demonstrating the workings of a mechanical crossbar switch with the help of a vintage Ericsson unit and an Arduino replacing the original’s bank of control relays.

It’s possible everyone has a hazy idea of a crossbar array, but it was fascinating from this video to learn that the relays are worked by metal fingers being inserted by the bars into relays with wider than normal gaps between electromagnet and armature. This extra metal provides a path for the magnetic flux to actuate the relay.

The machine itself then is an extremely simple and elegant electromechanical device with many fewer moving parts than its Strowger rotary equivalents, but surprisingly we seem to see less of it than its American competitor. The video below the break is definitely worth a watch, even if you don’t own any analogue phones.

We recently saw a similar exchange implemented electronically.

Continue reading “A Crossbar Telephone Switch Explained” →