Building The DIY HP41C: A Field Report

December 3, 2021 by Al Williams 20 Comments

I have a confession to make. I write about a lot of projects for Hackaday, but there are very few I read about and then go actually build a copy of it. I don’t have a lot of time and I’m usually too busy building my own stuff. But once in a while, something strikes my fancy and I’ll either raid the junk box or buy the kit. The most recent case of that was the PX-41C, a replica of the classic HP-41C.

The HP-41C is a somewhat legendary reverse-polish notation calculator. I still have my original HP-41C from 1979 (a very low serial number). It is still a workhorse but at 43 years old or so, I don’t like to leave it hanging around or near anything that might damage it. It has enough wear from the daily use it received 40 years ago. Sure, I have great emulation on my phone and I use that too, but the PX-41C kit looked fun, and with all through-hole parts it would be a quick build. The black Friday sale on Tindie sealed the deal for me.

Start-Up

The kit arrived on the Saturday after Thanksgiving, I decided to tackle it while waiting for some 3D prints. The components were all nicely bagged and marked. Tearing into the bags was a bit frustrating, but not hard and it did keep everything separate. There was a bill of materials, but — I thought — no instructions. Turns out the last part of the bill of materials is a link to some instructions. They aren’t much and I didn’t realize they were until after completing the board, but it isn’t hard to figure out. All the parts are marked on the silkscreen and you can probably figure it out — with a few caveats.

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Hackaday Podcast 147: Animating Traces, Sucking And Climbing, Spinning Sails, And Squashing Images

December 3, 2021 by Mike Szczys 2 Comments

Hackaday editors Mike Szczys and Elliot Williams get caught up on the week that was. You probably know a ton of people who have a solar array at their home, but how many do you know that have built their own hydroelectric generation on property? Retrocomputing software gurus take note, there’s an impressive cross-compiler in town that can spit out working binaries for everything from C64 to Game Boy to ZX Spectrum. Tom took a hard look at the Prusa XL, and Matthew takes us back to school on what UEFI is all about.

Take a look at the links below if you want to follow along, and as always, tell us what you think about this episode in the comments!

Direct download (55 MB)

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Moon Bouncing And Radar Imaging With LoRa

December 3, 2021 by Ryan Flowers 17 Comments

The LoRa radio protocol is well known to hardware hackers because of its Long Range (hence the name) but also its extremely low power use, making it a go-to for battery powered devices with tiny antennae. But what if the power wasn’t low, and the antenna not tiny? You might just bounce a LoRa message off the moon. But that’s not all.

The team that pulled off the LoRa Moonbounce consisted of folks from the European Space Agency, Lacuna Space, and the CA Muller Radio Astronomy Station Foundation which operates the Dwingeloo Radio Telescope. The Dwingeloo Radio Telescope is no stranger to Amateur Radio experiments, but this one was unique.

LoRa Moonbounce plotted for doppler shift by frequency — A radar image of the moon generated from LoRa Moonbounce

Operating in the 70 cm Amateur Radio band (430 MHz) meant that the LoRa signal was not limited to the low power signals allowed in the ISM bands. The team amplified the signal to 350 Watts, and then used the radio telescope’s 25 Meter dish to direct the transmission toward the moon.

The result? Not only were they able to receive the reflected transmission using the same transceiver they modulated it with — an off the shelf IOT LoRa radio — but they also recorded the transmission with an SDR. By plotting frequency and doppler delay, the LoRa transmission was able to be used to get a radar image of the moon- a great dual purpose use that is noteworthy in and of itself.

LoRa is a versatile technology, and can even be used for tracking your High Altitude Balloon that’s returned to Terra Firma.

This Week In Security: GoDaddy, Tardigrade, Monox, And BigSig

December 3, 2021 by Jonathan Bennett 10 Comments

After the Thanksgiving break, we have two weeks of news to cover, so hang on for an extra-long entry. First up is GoDaddy, who suffered a breach starting on September 6th. According to an SEC filing, they noticed the problem on November 17th, and determined that there was unauthorized access to their provisioning system for their WordPress hosting service. For those keeping track at home, that’s two months and eleven days that a malicious actor had access. And what all was compromised? The email address and customer number of the approximate 1.2 million GoDaddy WordPress users; the initial WordPress password, in the clear; the SFTP and database passwords, also in the clear; and for some customers, their private SSL key.

The saving grace is that it seems that GoDaddy’s systems are segregated well enough that this breach doesn’t seem to have led to further widespread compromise. It’s unclear why passwords were stored in the clear beyond the initial setup procedure. To be safe, if you have a WordPress instance hosted by GoDaddy, you should examine it very carefully for signs of compromise, and rotate associated passwords. The SSL keys may be the most troubling, as this would allow an attacker to impersonate the domain. Given the length of time the attack had access, it would not surprise me to learn that more of GoDaddy’s infrastructure was actually compromised. Continue reading “This Week In Security: GoDaddy, Tardigrade, Monox, And BigSig” →

IPod, Therefore I Am: Looking Back At An Original IPod Prototype

December 3, 2021 by Ryan Flowers 17 Comments

Have you ever wondered what consumer electronics look like when they’re in the ugly prototype stages? So have we. And thanks to [Cabel] of at Panic.com, we have a rare glimpse at a prototype first generation Apple iPod.

In the days before you could just stream your favorite music directly from your phone and into your Bluetooth speaker, pods, or car, there was the Sony Walkman and various portable tape players. Then there were portable CD players. As MP3’s became a popular format, CD players that could play MP3’s on home made CD’s were popular. Some portable digital media players came to market in the mid 1990’s. But in October of 2001, the scene changed forever when Apple unveiled the first generation iPod.

Of course, the iPod didn’t start out being so svelte, shiny, and downright cool. This engineering prototype has been hiding in [Cabel]’s closet for almost 20 years and they’ve just now decided to share with us its hilariously oversized case, JTAG port, and square pushbuttons that look like they came from a local electronics supply house. As [Cabel] brings out in the excellent writeup, the hardware itself is very close to production level, and the date on the prototype is very near the actual product launch.

Of course prototyping is an essential part of building any product, production or otherwise. Having a gander at such pre-production devices like this, or these off-ear speaker prototype for Valve’s VR headset reminds us just how important even the ugliest prototypes can be.

Have you got any pre-production nuggets to share with the world? Be sure to let us know by dropping a note in the Tip Line, and thanks to [jp] who sent this one in!

Homebrew 16 Bit Computer Reinvents All The Wheels

December 3, 2021 by Ryan Flowers 23 Comments

Building your own computer has many possible paths. One can fabricate their own Z80 or MOS 6502 computers and then run a period correct OS. Or a person could start from scratch as [James Stanley] did. [James] has invented a completely unique computer and CPU he calls SCAMP. SCAMP runs a custom OS called SCAMP/os which you can check out in the video below the break.

[James] describes the CPU and computer as purposefully primitive. Built out of discrete 74xx series logic chips, it runs at a fast-enough-for-homebrew 1 MHz. Plus, it has a lot of blinking lights that can’t help but remind us of the original Imsai 8080. But instead of a panel of switches for programming, the SCAMP/os boots to a shell, which is presented through a serial terminal. Programs are written in a bespoke language with its own compiler. The OS is described as a having a Unix-like feel with CP/M-like functionality. That’s quite a combination!

What we love most about the build, other than its clean looks and blinkenlights, is the amount of work that [James] has put into documenting the build both on his blog and on Github, where the source code and design is available. There’s also an open invitation for contributors to help advance the project. We’re sure he’ll get there, one bit at a time.

While [James] is using a Compact Flash card for storage currently we can’t help but wonder if a Cassette Tape storage system might be a worthwhile future upgrade.

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Smart Ruler Has Many Features

December 2, 2021 by Bryan Cockfield 12 Comments

For those of us who remember old ball mice, they were a lot like modern optical mice except that they needed to be cleaned constantly. Having optical mice as a standard way of interacting with a computer is a major improvement over previous eras in computing. With extinction of the ball mouse, there are an uncountable number of cheap optical mice around now which are easy pickings for modern hacking, and this latest project from [Vipul] shows off some of the ways that optical mice can be repurposed by building a digital ruler.

The build seems straightforward on the surface. As the ruler is passed over a surface the device keeps track of exactly how far it has moved, making it an effective and very accurate ruler. To built it, the optical component of a mouse was scavenged and mated directly to a Raspberry Pi Zero W over USB. Originally he intended to use an ESP32 but could not get the USB interface to work. [Vipul] was then able to write some software which can read the information from the mouse’s PCB directly and translate it into human-readable form where it is displayed on a small screen. The entire device is housed in a custom 3D-printed enclosure to wrap everything up, but the build doesn’t stop there though. [Vipul] also leveraged the Bluetooth functionality of the Pi and wrote a smartphone app which can be used to control the ruler as well.

While the device does have some limitations in that it has to make contact with the object being measured across its entire length, there are some situations where we can imagine something like this being extremely useful especially when measuring things that aren’t a straight line. [Vipul] has also made all of the code for this project publicly available for those of us who might have other uses in mind for something like this. We’ve seen optical mice repurposed for all kinds of things in the past, too, including measuring travel distances in autonomous vehicles.

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