Getting Dial-Up To Work Over VOIP Isn’t Always Easy

December 19, 2024 by Lewin Day 23 Comments

Dial-up modems used to be the default way of accessing the Internet, but times have moved on. They’re now largely esoteric relics from a time gone by. With regular old phone lines rather hard to come by these days, [Peter Mount] decided to try getting a pair of dial-up modems working over VoIP instead.

The build started with a pair of Linksys PAP2T VoIP phone adapters, which were originally designed for hooking regular phones up to VoIP systems. He paired each US Robotics modem with a PAP2T, and then hooked both into a VoIP Private Branch Exchange which he set up using 3cx on a Raspberry Pi 3B+. The Pi also acted as a server for the modems to connect to. It took a lot of fiddly configuration steps, but he found success in the end. On YouTube, he demonstrates the setup—with that glorious modem sound—communicating successfully at a rate of 9600 baud.

It’s nice to see this vintage hardware communicating in a what is effectively a simulated world created entirely within modern hardware. We’ve seen similar projects before, like this attempt to get dial-up going over Discord. If you’re doing your own odd-ball screechy communications experiments, don’t hesitate to drop us a line!

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The Tsushin Booster – A PC Engine Modem Add-on With A Twist

November 2, 2024 by Dave Rowntree 5 Comments

Sometimes, hardware projects get cancelled before they have a chance to make an impact, often due to politics or poor economic judgment. The Tsushin Booster for the PC Engine is one such project, possibly the victim of vicious commercial games between the leading Japanese console manufacturers at the tail end of the 1980s. It seems like a rather unlikely product: a modem attachment for a games console with an added 32 KB of battery-backed SRAM. In addition to the bolt-on unit, a dedicated software suite was provided on an EPROM-based removable cartridge, complete with a BASIC interpreter and a collection of graphical editor tools for game creation.

Internally, the Tsushin booster holds no surprises, with the expected POTS interfacing components tied to an OKI M6826L modem chip, the SRAM device, and what looks like a custom ASIC for the bus interfacing.

It was, however, very slow, topping out at only 1200 Baud, which, even for the period, coupled with pay-by-minute telephone charges, would be a hard sell. The provided software was clearly intended to inspire would-be games programmers, with a complete-looking BASIC dialect, a comms program, a basic sprite editor with support for animation and even a map editor. We think inputting BASIC code via a gamepad would get old fast, but it would work a little better for graphical editing.

PC Engine hacks are thin pickings around these parts, but to understand a little more about the ‘console wars’ of the early 1990s, look no further than this in-depth architectural study. If you’d like to get into the modem scene but lack original hardware, your needs could be satisfied with openmodem. Of course, once you’ve got the hardware sorted, you need some to connect to. How about creating your very own dial-up ISP?

A Brand New USB Modem In The 2020s

September 17, 2024 by Jenny List 11 Comments

The dulcet tones of a modem handshake may be a thing of the distant past for most of us, but that hasn’t stopped there being a lively hacking scene in the world of analogue telephones. Often that’s achieved using old devices resurrected from a parts bin, but sometimes, as with [Brian]’s USB modem, the devices are entirely new.

A surprise is that modem chips are still available, in this case the SkyWorks IsoModem chips. It uses an M.2 module format to allow the modem and support circuitry to be separated enough to place it in another project if necessary, along with a clear warning on the PCB not to put it in the identical-looking PC slot. It also comes with tips for experimenting if you don’t have access to a landline too, given that POTS is fast becoming a thing of the past itself in so many places.

If you’ve got nowhere to show off your modem, we’d like to suggest you try a hacker camp. There you’ll often find a copper network you’re positively expected to hack.

The JawnCon 0x1 Badge Dials Up A Simpler Time

September 16, 2024 by Tom Nardi 10 Comments

For hackers of a certain age, the warbling of an analog modem remains something of a siren song. Even if you haven’t heard it in decades, the shrill tones and crunchy static are like a time machine that brings back memories of a bygone era. Alien to modern ears, in the 1980s and 90s, it was the harbinger of unlimited possibilities. An audible reminder that you were about to cross the threshold into cyberspace.

If you can still faintly hear those strangely comforting screeches in the back of your mind, the JawnCon 0x1 badge is for you. With a row of authentic vintage red LEDs and an impeccably designed 3D-printed enclosure, the badge is essentially a scaled-down replica of the Hayes SmartModem. But it doesn’t just look the part — powered by the ESP8266 and the open source RetroWiFiModem project, the badge will allow attendees to connect their modern computers to services from the early Internet via era-appropriate AT commands while they’re at the con.

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Pulling Apart An Old Satellite Truck Tracker

September 13, 2024 by Lewin Day 9 Comments

Sometimes there’s nothing more rewarding than pulling apart an old piece of hardware of mysterious origin. [saveitforparts] does just that, and recently came across a curious satellite system from a surplus store. What else could he do, other than tear it down and try to get it humming?

The device appeared to be satellite communication device for a tracking unit of some sort, complete with a long, thick proprietary cable. That led to a junction box with a serial port and an RJ45 port, along with some other interfaces. Disassembly of the unit revealed it contained a great deal of smarts onboard, including some kind of single-board computer. Comms-wise, it featured a cellular GPRS interface as well as an Orbcomm satellite modem. It also packed in GPS, WiFi, Xbee, Ethernet, and serial interfaces. It ultimately turned out to be a Digi ConnectPort X5 device, used as a satellite tracking system for commercial trucks.

What’s cool is that the video doesn’t just cover pulling it apart. It also dives into communicating with the unit. [saveitforparts] was able to power it up and, using the manufacturer’s software, actually talk to the device. He even found the web interface and tested the satellite modem.

Ultimately, this is the kind of obscure industry hardware that most of us would never come into contact with during our regular lives. It’s neat when these things show up on the secondary market so hackers can pull them apart and see what makes them tick. Video after the break.

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It’s Spreadsheets All The Way Down For This 80s Handheld

September 5, 2024 by Bryan Cockfield 9 Comments

Unlike the today’s consumer computer market, the 1980s were the wild west in comparison. There were all kinds of different, incompatible operating systems, hardware, and programs, all competing against one another, and with essentially no networking to tie everything together. Some of these products were incredibly niche as well, only running one program or having a limited use case to keep costs down. Such was the Convergent WorkSlate, a computer that ran only a spreadsheet with any programs also needing to be built into a spreadsheet.

Upon booting the device, the user is presented with a fairly recognizable blank spreadsheet, albeit with a now-dated LCD display (lacking a backlight) and a bespoke keyboard and cursor that wouldn’t have allowed for easy touch typing. The spreadsheet itself is quite usable though, complete with formatting tools and the capability to use formulas like a modern spreadsheet program would. It also hosted a tape deck for audio and data storage, a modem for communicating with other devices, and an optional plotter-style printer. The modem port is how [Old VCR] eventually interfaces with the machine, although as one can imagine is quite a task for a piece of small-batch technology from the 80s like this. After learning how to send and receive information, a small game is programmed into the machine and then a Gopher interface is built to give the device limited Internet connectivity.

The investigation that [Old VCR] goes into on this project to get this obsolete yet unique piece of hardware running and programmed to do other tasks is impressive, and worth taking a look at especially because spreadsheets like this aren’t Turing-complete, leading to a few interesting phenomenon that most of us wouldn’t come across in the modern computing world. Since only around 60,000 units were ever made it’s difficult to come across these machines, but if you want to take a look at the spreadsheet world of the 80s without original hardware you can still run Lotus 1-2-3 natively in Linux today.

Thanks to [Cameron] for the tip!

Ancient Cable Modem Reveals Its RF Secrets

April 22, 2024 by Dan Maloney 27 Comments

Most reverse engineering projects we see around here have some sort of practical endpoint in mind. Usually, but not always. Reverse-engineering a 40-year-old cable modem probably serves no practical end, except for the simple pleasure of understanding how 1980s tech worked.

You’ll be forgiven if the NABU Network, the source of the modem [Jared Boone] tears into, sounds unfamiliar; it only existed from 1982 to 1985 and primarily operated in Ottawa, Canada. It’s pretty interesting though, especially the Z80-based computer that was part of the package. The modem itself is a boxy affair bearing all the hallmarks of 1980s tech. [Jared]’s inspection revealed a power supply with a big transformer, a main logic board, and a mysterious shielded section with all the RF circuits, which is the focus of the video below.

Using a signal generator, a spectrum analyzer, and an oscilloscope, not to mention the PCB silkscreen and component markings, [Jared] built a block diagram of the circuit and determined the important frequencies for things like the local oscillator. He worked through the RF section, discovering what each compartment does, with the most interesting one probably being the quadrature demodulator. But things took a decidedly digital twist in the last compartment, where the modulated RF is turned into digital data with a couple of 7400-series chips, some comparators, and a crystal oscillator.

This tour of 80s tech and the methods [Jared] used to figure out what’s going on in this box were pretty impressive. There’s more to come on this project, including recreating the original signal with SDRs. In the mean time, if this put you in the mood for other videotext systems of the 80s, you might enjoy this Minitel terminal teardown.

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