Discovering little worlds

Like so many other people during the COVID lockdown, I’ve been looking for additional hobbies that could be done from home, which would occupy my time and help keep my mind off the collapse of civilization as we know it, and maybe even ground my thoughts and keep them away from hyperbole and catastrophizing.

While cleaning and organizing my basement I came across this small USB device. It’s barely larger than a flash drive, but it’s no flash drive at all — it’s a software-defined radio (SDR), namely an RTL-SDR V3 dongle.

I don’t even recall how this device ended up in my possession;  I think it was probably from one of my previous jobs:  they were throwing away a bunch of equipment that was no longer useful, and allowed me to keep some of the items.  Regardless, I had never actually used the SDR, and hadn’t really thought about what the SDR would be useful for.  I had a vague understanding that the SDR can let me tune in to any random radio frequency, but how interesting can that be?  Well, it turns out that playing around with this device led me into a rabbit hole of epic proportions.

Once I found the right software to work with the SDR device (SDRSharp for Windows, and CubicSDR for Mac), I was up and running.  The first rather trivial thing to do was to tune in to the local FM radio stations. Here they are, as viewed through a spectrogram:

FM radio

But that’s kind of boring. I wonder what lies outside of the FM radio band? Well, the next obvious destination is the local police frequencies, which are around 460 MHz to 490 MHz in my area. These are narrow-band FM (NFM) stations, so we adjust our software settings accordingly. In mere moments, I’m listening to police dispatchers communicating with units and telling them about robberies, car accidents, and the like:

And of course there are a few local HAM radio repeaters nearby, which tells me that the HAM community is very much alive and well.  Since I can’t transmit anything using my tiny SDR device, I can only listen in on the HAM conversations, but that’s okay since the conversation wasn’t particularly scintillating anyway, and I’m not sure that getting into the little world of HAM radio is really my goal here. As much as I salute the enthusiasts who keep HAM radio going, they can party on without me.

Mind you, all of this was using the cheap tiny antenna that came with the SDR itself.  But then I discovered that the SDR can be used for something else entirely: receiving signals from satellites!

Arguably the easiest satellites to pick up signals are the NOAA 15/18/19 satellites, which are weather satellites that transmit images of cloud cover over the ground. By “easiest” I mean requiring the least amount of additional equipment:  it only requires a rabbit-ear (V-dipole) antenna connected to your SDR, and a cloud-free day to get a good signal. Here is the signal at 137.9 MHz, and the resulting image, which is produced by special software that demodulates the “audio” data that was recorded:

The downside is that these satellites are in a sun-synchronous orbit, and will only pass by your location for ~15-minute intervals at the most, and can only be caught at very early or late hours of the day. The other downside is that the NOAA satellites are aging, and will probably be decommissioned in the coming years. And anyway, the images they transmit are not the highest quality. Time to step it up to the next level, namely the GOES satellites!

The GOES-16 satellite is a newer weather satellite that is geostationary, and is positioned permanently above the Americas. In fact its longitude is almost exactly over the East coast, which is perfect for my purposes, and its inclination from my location is about 45 degrees (because it orbits around the equator, as all geostationary satellites must do).

But because it’s geostationary it’s also much farther away, and therefore its signal is much weaker, and requires additional equipment:

The setup consists of an old WiFi grid antenna, which feeds into a SAW filter and amplifier, which then feeds into the SDR that’s now connected to a Raspberry Pi (the total cost was about $100).  The Raspberry Pi is running a package called goestools which demodulates the signal from the satellite in real time, and translates the signal into images. The satellite transmits images of Earth in many different spectral bands, ranging from visible light to deep infrared.

And so, the final little world I discovered on this adventure is this one:

The full resolution of these images is 10K, which is mind-blowing, and my next step is to create animations from these images, which are sent by the satellite every 15 minutes.

I think I’ll leave this antenna setup as a permanent installation in my house, so that I can grab these signals anytime I like. Even though this imagery is available on the web if you know where to look, there is something profoundly awesome in knowing that you personally can receive selfies of our world, from 35,000 kilometers away, using about $100 worth of equipment. It’s been a very satisfying few weeks, in spite of everything else that’s happening this year.

Thoughts on the new Star Trek

I watched Star Trek: Picard recently, and… I am sad.

Gene Roddenberry had a vision: a future which is truly post-racial, post-war, post-poverty, etc. It’s a world for us to strive towards, to admire, to want to live in.  But the world of Star Trek: Picard seems to have all the same problems we have in the 21st century.  The Federation is a systemically racist organization that refuses to help an enemy in a time of desperate need. There is deep wealth inequality between different classes of people on Earth. People treat sentient androids like property. And all of “space” is a hostile battleground where one dares not venture without being armed to the teeth.

That’s not a world I look forward to living in, and it would be depressing to me if this is how humanity “turns out” in three hundred years.

Aside from pontificating about today’s political issues, the show’s plot is completely incoherent, and the writing is so lazy and unfocused. Remember Picard’s caretakers at his château who were former Tal Shiar? Those were some interesting characters, but will we ever see them again? Was there any point in having the Borg involved in the story at all? Does the Romulan Samurai kid (bet you can’t think of his name!) have any purpose than to chop people’s heads off? Will Agnes’s murder of Bruce Maddox be swept under the rug? Will the fact that Picard is now a synthetic golem ever be mentioned again?

One perfect example of lazy writing is embodied in the hand-held purple repair device that the Androids conveniently give to Captain Rios. This device basically grants wishes: you can wish it to repair your broken warp core! Or you can wish it to create a mirage of a hundred starships, complete with warp signatures that can fool Romulan sensors! What luck!

And think about how Old Trek and New Trek are different in terms of fandom. There are fans who transform their basement to look like the bridge of the Enterprise. There are fans who program their desktop computer to look like an LCARS interface. And of course there are countless fans who attend conventions dressed up like characters from the Original Series and Next Generation. But will there be any fans who’ll want to recreate the bridge of Captain Rios’s ship (bet you don’t know what it’s called)? Will there be any fans who will admire or want to emulate any of these new characters?

Is it possible anymore to have a show where the whole universe isn’t about to blow up all the time? Can we just have a show where the Enterprise goes to a planet, and Picard negotiates a peace accord, while Data and Geordi get into a wacky holodeck adventure?  I ask for so precious little!

Reverse engineering a 25-year-old Visual Basic app

Following up from last week’s misadventures with the Avant Stellar keyboard (trying and failing to extract macro information from the keyboard’s internal memory), there was another glimmer of hope:  my friend found a backup file that possibly contains all the macros that were saved to the keyboard.  If I could just reverse-engineer this backup, we could extract the macros directly from the file.  It is a 2 KB file with a .KBD extension, unrecognizable as any binary format I’ve seen to date. Here is a partial hex dump of the file:

It’s pretty clear that the file contains a key mapping, as evidenced by the list of incrementing 32-bit numbers at the beginning, up to offset 0x210.  There are roughly 120 increasing numbers, which is roughly the number of keys on the keyboard, so we can safely assume that this is the key mapping.  After the key mapping, I presume, comes the macro information, and this is where things get tricky, since there’s virtually no way to tell how the macros are encoded in the file. The data simply looks too general to make sense of.

An obvious possibility would be to “load” the backup file into the Avant software tool that came with the keyboard, and visually inspect the macro(s) assigned to each key.  But no matter what I tried, the software would not load the file.  Or rather, it loaded the key mapping, but not the macros.  Time to think about the nuclear option: disassemble the Avant software and see how it’s actually processing the backup file.

Looking at the folder contents of the Avant software tool, I immediately notice a dead giveaway: VBRUN300.DLL, which means this tool was written in Visual Basic 3.0.  This makes our job much easier, because there are actually ready-made tools for decompiling Visual Basic executables. (If you recall, Visual Basic compiles executables into p-code instead of native machine code, which makes them much more straightforward to decompile.)  All of this took me quite a while to remember, because I hadn’t used these tools since my early, early hacking days, and it took a little while longer to find them in my archives!  The go-to utility for performing this task was literally called VB3 Decompiler, and the way to find this tool on the web today is… outside the scope of this post.

The decompilation basically results in several Visual Basic source files, in which the original function names are intact, but the local and global variables are changed to generic identifiers, since those names are not stored in the compiled code. It takes a little bit of further massaging to get these files to actually build within Visual Basic, but after that, it’s almost as if you have the original source code of the program at your fingertips.

There was one other minor hurdle because the Avant software uses custom UI components (.VBX files) that don’t allow themselves to be used in Design mode (as part of a copy-protection or licensing mechanism), but this is bypassable using another utility in the decompiler suite that “fools” Visual Basic into loading the components anyway.

With the source code buildable and debuggable, we can now easily run the program and load the .KBD backup file, and trace through where it processes the data in the file:

Even though the variable names aren’t very descriptive in the above screenshot, it’s easy enough to spot the loop that deserializes the keyboard macros, and how each macro is composed.  Not only that, but we can determine what was preventing it from displaying the macros in the first place — it turned out that it expects the keyboard to be physically connected while running, and while I’m pretty sure that we tried loading the backup with the keyboard attached, it wasn’t working anyway, probably because the keyboard is malfunctioning and no longer able to communicate properly.  But at last, with this requirement bypassed, the macros that were loaded from the backup file finally reveal themselves:

Recovering data from QIC-80 tapes: another case study

In another of my recent data recovery cases, the patient was a QIC-80 (DC 2000 mini cartridge) tape that was in pretty bad shape. From the outside I could already see that it would need physical repairs, so I opened it up and found a harrowing sight:

The problem with QIC cartridges in general is that they use a tension band to drive the tape spools. If you look at a QIC cartridge, it’s completely enclosed, except for a plastic wheel that sticks out and makes contact with the capstan mechanism when it’s inserted into the tape drive.  The flexible tension band is tightened in such a way that it hugs the tape spools and drives them using physical friction.

This tension band is a major point of weakness for these types of tapes, because the lifespan of the band is very much finite.  When the tape sits unused for many years, the band can stiffen or lose its friction against the tape spools, which can result in one of two scenarios:

The tension band can break, which would make the cartridge unusable and would require opening the cartridge and replacing the band. This is actually not the worst possible outcome because replacing the band, if done properly, isn’t too disruptive of the tape medium itself, and usually doesn’t result in any data loss.

A much worse scenario is if the tension band becomes weakened over time, such that it no longer grips the spools properly, so that the next time you attempt to read the cartridge, it will spin the spools inconsistently (or cause one of the spools to stall entirely), which will cause the tape to bunch up between the spools, or bend and crease, creating a sort of “tape salad” inside the cartridge, all of which can be catastrophic for the data on the tape. In this kind of case, the cartridge would need to be disassembled and the tape manually rewound onto the spools, being extremely careful to undo any folds or creases (and of course replace the band with a new one, perhaps from a donor tape). This will almost certainly result in loss of data, but depends greatly on the degree to which the tape was unwound and deformed.

Note that the tape drive that is reading the tape is relatively “dumb” with respect to the physical state of the tape. It has no way of knowing if the tension band is broken, or if the tape isn’t wound or tensioned properly, or if what it’s doing is damaging the tape even further. Great care must be taken to examine the integrity of the tape before attempting to read it.

With this cartridge, it’s clear that the tension band has failed (but didn’t break). The tape has obviously bunched up very badly on both spools.  Less obviously, the white plastic wheels at the bottom show evidence that the tension band has degraded, with bits of residue from the black band being stuck on the wheels. The fix for this cartridge was to remove the bad tension band, clean the white plastic wheels, respool and tighten the tape, and install a new band from a donor tape. After the procedure was complete, more than 99% of the data was recovered. The tape header was readable, as were the volume tables. Only a few KB of the file contents were lost.

Therefore, when recovering data from very old QIC tapes, it’s probably a good idea to replace the tension band preemptively with a known-good band, to minimize the chance of breakage and damage to the tape. This is why I keep a small stockpile of new(er) tapes from which I can harvest the tension band when needed. At the very least, it’s a good idea to open up the cartridge and examine the band before making any attempts to read data from it.

Where did we go wrong?

I started programming seriously in the late 1990s, when the concept of “visual” IDEs was really starting to take shape. In one of my first jobs I was fortunate enough to work with Borland Delphi, as well as Borland C++Builder, creating desktop applications for Windows 95.  At that time I did not yet appreciate how ahead of their time these tools really were, but boy oh boy, it’s a striking contrast with the IDEs that we use today.

Take a look: I double-click the icon to launch Delphi, and it launches in a fraction of a second:

But it also does something else: it automatically starts a new project, and takes me directly to the workflow of designing my window (or “Form” in Borland terms), and writing my code that will handle events that come from the components in the window. At any time I can click the “Run” button, which will compile and run my program (again, in a fraction of a second).

Think about this for a bit. The entire workflow, from zero to building a working Windows application, is literally less than a second, and literally two clicks away.  In today’s world, in the year 2020, this is unheard of.  Show me a development environment today that can boast this level of friendliness and efficiency!

The world of software seems to be regressing: our hardware has been getting faster and faster, and our storage capacity larger and larger, and yet our software has been getting… slower. Think about it another way: if we suppose that our hardware has gotten faster by two orders of magnitude over the last 20 years, and we observe that our software is noticeably slower than it was 20 years ago, then our software has gotten slower by two orders of magnitude! Is this… acceptable? What on earth is going on?

Laziness

Engineers like to reuse and build upon existing solutions, and I totally understand the impulse to take an existing tool and repurpose it in a clever way, making it do something for which it wasn’t originally intended. But what we often fail to take into account is the cost of repurposing existing tools, and all the baggage, in terms of performance and size, that they bring along and force us to inherit.

Case in point: suppose that the only language you know is JavaScript, and suppose that you wanted to start building desktop applications, but didn’t want to learn the languages and tools normally associated with desktop development, e.g. C++, C#, etc. What can you do? Well, one option would be to build a compiler from scratch, which would actually compile JavaScript into native machine code. But that would be hard. How about a simpler solution: take a full-blown web browser, and literally bundle it as the engine that will run your desktop app, with the logic of your app being in JavaScript, and the “window” of your app becoming a web page that is run by the bundled browser! This is, of course, the idea behind Electron, an alarmingly popular framework for building desktop apps today.

But what about the cost of using Electron? What is the cost of bundling all of Chromium just to make your crappy desktop app appear on the screen? Just to take an example, let’s look at an app called Etcher, which is a tool for writing disk images onto a USB drive. (Etcher is actually recommended by the Raspberry Pi documentation for copying the operating system onto an SD card.)

We know how large these types of tools are “supposed” to be (i.e. tools that write disk images to USB drives), because there are other tools that do the same thing, namely Rufus and Universal USB Installer, both of which are less than 2 MB in size, and ship as a single executable with no dependencies. And how large is Etcher by comparison? Well, the downloadable installer is 130 MB, and the final install folder weighs in at… 250 MB. There’s your two-orders-of-magnitude regression! Looking inside the install folder of Etcher is just gut-wrenching:

Why is there a DLL for both OpenGL and DirectX in there? Apparently we need a GPU to render a simple window for our app. The “balenaEtcher” executable is nearly 100 MB itself. But do you see that “resources” folder? That’s another 110 MB! And do you see the “locales” folder? You might think that those are different language translations of the text used in the app. Nope — it’s different language translations of Chromium. None of it is used by the app itself. And it’s another 5 MB. And of course when Etcher is running it uses 250+ MB of RAM, and a nonzero amount of CPU time while idle. What is it doing?!

As engineers, this is the kind of thing that should make our skin crawl. So why are we letting this happen? Why are we letting software get bloated beyond all limits and rationalize it by assuming that our hardware will make up for the deficiencies of our software?

The web

The bloat that has been permeating the modern web is another story entirely. At the time of this writing, the New York Times website loads nearly 10 MB of data on a fresh load, spread over 110 requests. This is quite typical of today’s news websites, to the point where we don’t really bat an eye at these numbers, when in fact we should be appalled. If you look at the “source” of these web pages, it’s tiny bits of actual content buried in a sea of <script> tags that are doing… something? Fuck if I know.

The bloat seen on the web, by the way, is being driven by more nefarious forces than sheer laziness. In addition to building a website using your favorite unnecessaryframework” that you can choose willy-nilly (which varies with every web developer you ask, and then has to be hosted on a separate CDN because your web server can’t handle the load), you also have to integrate analytics packages into your website, as requested by your marketing department, and another analytics package requested by your user research team, and another analytics package requested by your design team, etc. If one of the analytics tools goes out of fashion, leave the old code in! Who knows, we might need to switch back to it someday. It doesn’t seem to be impacting load speeds… much… on my latest MacBook Pro. The users won’t even notice.

And of course, ads. Ads everywhere. Ads that are basically free to load whatever arbitrary code they like, and are totally out of the control of the developer. Oh, you say the users are starting to use ad blockers? Let’s add more code that detects ad blockers and forces users to disable them!

The web, in other words, has become a dumpster fire. It’s a dumpster fire of epic proportions, and it’s not getting better.

What to do?

What we need is for more engineers to start looking at the bigger picture, start thinking about the long term, and not be blinded by the novelty of the latest contraption without understanding its costs. Hear me out for a second:

  • Not everything needs to be a “framework” or “library.” Not everything needs to be abstracted for all possible use cases you can dream of. If you need code to do something specific, sometimes it’s OK to borrow and paste just the code you need from another source, or god forbid, write the code yourself, rather than depending on a new framework. Yes, you can technically use a car compactor to crack a walnut, but a traditional nutcracker will do just fine.
  • Something that is clever isn’t necessarily scalable or sustainable. I already gave the example of Electron above, but another good example is node.js, whose package management system is a minor dumpster fire of its own, and whose dependency cache is the butt of actual jokes.
  • Sometimes software needs to be built from scratch, instead of built on top of libraries and frameworks that are already bloated and rotting. Building something from the ground up shouldn’t be intimidating to you, because you’re an engineer, capable of great deeds.
  • Of course, something that is new and shiny isn’t necessarily better, either. In fact, “new” things are often created by fresh and eager engineers who might not have the experience of developing a product that stands the test of time. Treat such things with a healthy bit of skepticism, and hold them to the same high standards as we hold mature products.
  • Start calling out software that is bad, and don’t use it until it’s better. As an engineer you can tell when your fellow engineers can do a better job, so why not encourage them to do better?
  • Learn to say No! When the newest JavaScript framework starts making its rounds, or when the latest “cross-platform” app development framework is unveiled, or when everyone starts talking about microservices, it’s OK to say “No!” “No, thank you!” “Not until we understand how this will be beneficial to us five years from now.” “Not until we understand the costs, in terms of space, performance, and sanity, of adopting this new thing.”

I suppose that with this rant I’m adding my voice to a growing number of voices that have similarly identified the problem and laid it out in even greater detail and eloquence than I have. I wish that more developers would write rants like this. I wish that this was required training at universities. I have a sinking feeling, however, that these rants are falling on deaf ears, which is why I’ll add one more suggestion that we, as engineers, can do to raise awareness of the issue:

Educate regular users about how great software can be. Tell your parents, your friends, your classmates, that a web page shouldn’t actually need ten seconds to load fully. Or that they shouldn’t need to purchase a new generation of laptop every two years, just to keep up with how huge and slow the software is becoming. Or that the software they install could be one tenth of its size, freeing up that much more space for their photos or documents, for example. That way, regular users can be as fed up as we are about the current state of software, and finally start demanding us to do better.