As you read this, there are still people chatting away on Bulletin Board Systems all over the world. Running on newly written software and without the need to actually use a dial-up modem, these (slightly) more modern takes on the BBSs of yore can be compelling diversion for those who might want to decompress a bit from contemporary social networks.
[Blake Patterson] is one of these people, and he writes in to tell us about his recent experiments with using a particularly gorgeous example the Epson PX-8 “Geneva” laptop on modernized BBSs. The form factor of the device makes it a fairly convenient client for chatting, despite the somewhat unusual screen. Luckily, modern BBS software is able to cope with the PX-8’s 80 character by 8 line LCD display, it’s just a matter of getting the thing online.
The trick is tethering the PX-8 to a Linux machine as a serial terminal. [Blake] had to build a serial cable for the laptop, and then used a basic USB-to-serial converter to get it connected to a Raspberry Pi. Once you’ve logged in over serial, you can simply fire off a telnet command to connect to the BBS of your choice. In the video after the break, he demonstrates what it’s like browsing and chatting on a BBS using the PX-8. The screen certainly takes a bit of getting used to, but actually works fairly well given the nature of the BBS interface.
The R820T tuner IC is used in the popular Airspy software defined radio (SDR) as well as many of the inexpensive RTL SDR dongles. [TLeconte] did some experiments on intermediate frequency (IF) configuration of the chip, and you’ll find his results interesting.
Using 5 million samples per second and the device’s real mode, the tests look at a what comes out when the IC reads a noise source. There are two registers that set the IF parameters, but the tests show the effects these registers have in precise terms.
For sturdy utilitarianism, there were few designs better than the Western Electric Model 500 desk phone. The 500 did one thing and did it well, and remained essentially unchanged from the mid-1940s until Touch Tone phones started appearing in the early 70s. That doesn’t mean it can’t have a place in the modern phone system, though, as long as you’re willing to convert it into a cellphone.
Luckily for [bicapitate], the Model 500 has plenty of room inside the case once the network interface is removed, because the new electronics take up a fair bit of space. There’s no build log per se, but the photo album makes it clear what’s going on. An Arduino reads the hook switch and dial pulses, while a Fona GSM module takes care of the cellular side of things. It looks like a small electret mic and a speaker replace the original transmitter and receiver. As a nice touch, the original ringer is used, but instead of trying to drive it electrically, [bicapitate] came up with a simple cam mechanism on a small motor. Driven at the right speed, the cam hooks the clapper arm, rings one bell, then releases it to let the clapper spring back to hit the other bell. Everything is powered by a LiPo, so it could be taken to the local coffee shop for some hipster hijinks.
A flip-flop is one of the most basic digital electronic circuits. It can most easily be built from just two transistors, although they can and have been built out of vacuum tubes, NAND and NOR gates, and Minecraft redstone. Conventional wisdom says you can’t build a flip-flop with just one transistor, but here we are. [roelh] has built a flip-flop circuit using only one transistor and some bizarre logic that’s been slowly developing over on hackaday.io.
[roelh]’s single transistor flip-flop is heavily inspired by a few of the strange logic projects we’ve seen over the years. The weirdest, by far, is [Ted Yapo]’s Diode Clock, a digital clock made with diode-diode logic. This is the large-scale proof of concept for the unique family of logic circuits [Ted] came up with that only uses bog-standard diodes to construct arbitrary digital logic.
The single-transistor flip-flop works just like any other flip-flop — there are set and reset pulses, and a feedback loop to keep the whatever state the output is in alive. The key difference here is the addition of a clock signal. This clock, along with a few capacitors and a pair of diodes, give this single transistor the ability to store a single bit of information, just like any other flip-flop.
This is, without a doubt, a really, really weird circuit but falls well into territory that is easily understood despite being completely unfamiliar. The key question here is, ‘why?’. [roelh] says this could be used for homebrew CPUs, although this circuit is trading two transistors for a single transistor, two diodes, and a few more support components. For vacuum tube-based computation, this could be a very interesting idea that someone at IBM in the 40s had, then forgot to write down. Either way, it’s a clever application of diodes and an amazing expression of the creativity that can be found on a breadboard.
Electric lighting – is there anything it can’t do? Coming in all manner of forms and flavours, you can get everything from a compact reading lamp to a blindingly powerful worklight for your garage. Generally, different lights are built in different ways to suit their purpose, but it’s not the only way to do things. Enter [slisgrinder] and the MOSAIC Lighting System.
At its heart, MOSAIC is a way of building lighting rigs out of individual modules. Where it gets interesting is the design – they’re triangles! The boards carry a variety of LEDs and are laid out in a fashion that allows the power and data connections to be made between adjacent cells by laying them out next to each other. Many boards can be tesselated together to create larger, smaller, or unusually shaped arrays. The connections are well thought out, allowing the tiles to make a connection along any one of their 3 edges, regardless of orientation.
The project began out of a desire to grow okra in an otherwise inhospitable climate; to this end, there are both general work lighting modules as well as grow light versions with UV LEDs on board. The modules can be combined in different ways and command and control is done over RS-485.
A friend of mine once suggested that there should be a support group for burned-out former hackerspace directors. We could have our own Village of the Damned at summer camps, where we’d sit moodily in the gathering twilight sipping our bourbon and Club Mate and decrying whatever misfortunes came to our space to leave such visible mental scars, or gazing hollow-eyed into the laser-tinged haze and moving gently to the pulse of the chiptune music. “See that’s Jenny over there, she don’t say much“. Hackerspace noir, where the only entry criterion is being crazy enough to stand for election to your space’s board.
There must be spaces somewhere that live in such perfect harmony, in which a happy membership support a board for whom everything falls into place. Maybe the makerspace in [Dr. Seuss]’s Whoville would have that kind of atmosphere, but the reality of life is that every group is made up of both Grinch and Who. Keeping a diverse group of people harmonious is a huge challenge, but that’s what hackerspaces are really about — the people make the space.
There are several defined periods in the gestation of a hackerspace, and at least from where I’m sitting they relate to its member count. Some spaces pass through them all as they grow, while others are lucky enough to reach an equilibrium and spare themselves some of the drama.
If you recognise yourselves in some of the following then you have my commiserations, while if your space hasn’t got there yet or has managed to dodge some of the bullets then consider yourselves lucky.
We are now in a golden age of printed circuit boards. It wasn’t too long ago that making your own circuit boards either involved a lot of money, or slightly less money and using some proprietary garbage PCB layout tool. Now, every board house speaks Gerber, and you can get a ten-pack of PCBs from China for five bucks. This incredible cost reduction means people are making art with printed circuit boards. We’ve seen portraits, landscapes, and memes. This is truly the beginning of a new artistic medium rendered in fiberglass and soldermask.
For this week’s Hack Chat, we’re going to be talking all about PCB artwork. Our guest for this week’s Hack Chat will be [Andrew Sowa], an electrical engineer, a vocal advocate of KiCad, and the guy who made more of me money. The Benchoff Nickel was created by simply taking some of the fantastic illustrations from Hackaday’s own [Joe Kim] and applying KiCad’s Bitmap2Component tool. Since the creation of the nickel, [Andrew] has been working on extending his technique to cross-hatching, backlighting, and halftones.
In this Hack Chat, we’re going to be talking all about PCB artwork, including the very beginnings of PCB art where engineers hid a few easter eggs in the PCBs of Xboxen and other consumer electronics. Topics covered will be bitmap to SVG conversion (in Inkscape and Illustrator), KiCad footprint creation, and the more technical side of things with the limitations of PCB fabrication and the slightly different shades of beige FR4 comes in.