Reverse Engineering The Sound Blaster

June 19, 2019 by 42 Comments

The first sound card to output PCM audio — the kind you need for audio samples — wasn’t the Sound Blaster. The AdLib Music Synthesizer Card could output PCM audio over software. The AdLib card also cost $200 at the time of its release. This was too much for some, and in time the Creative Labs Sound Blaster was released for the rock-bottom price of $125. This was a more capable card, and in the years since prices on the used market have gone through the roof. In 1990, you could buy a Sound Blaster for a Benjamin and a half, in 2019, prices on eBay are reaching and exceeding $400.

With the prices of used cards so high, we start to get into the territory where it starts to make sense to reverse engineer and re-manufacture the entire card. This hasn’t been done before, but that’s no matter for [Eric Schlaepfer], or [@TubeTimeUS]; he’s done crazier projects before, and this one is no different.

In reverse-engineering the Sound Blaster, there are a few necessary components. The Sound Blaster had an OPL2 chip for sound synthesis, which you can get through various vendors. The trick, though, is the microcontroller. This is really just an 8051 with a custom mask ROM.

The goal of this project is actually just to dump the ROM on the Intel 8051-alike microcontroller. This is something that’s relatively commonly done in high-tech labs, and luckily the Bay Area has [John McMaster], the guy who will take you into his lab and strip a die from its epoxy. Looking at the chip under the microscope, it was discovered the mask ROM on this chip was an implant ROM, with the ones and zeros represented by invisible ions in the substrate itself. There was no hope of reverse-engineering this chip from a purely visual inspection, but there was a sense amplifier on one of the data lines. By probing this sense amplifier while running through the address space, [Eric] was able to dump all the bytes of the ROM one bit at a time.

However, and there’s always a however, there are clone Sound Blasters out there, usually from China, and you can dump these chips if you’re lucky enough to get your hands on one. [Eric] reached out to the community and found these clone microcontrollers didn’t have the code protect bit set; dumping these was easy. This ROM was compared to the work [Eric] did with the sense amplifier, and after figuring out the order of the bits, it was found the code matched. The code was successfully cloned, and now new Sound Blasters can be made. Don’t tell eBay that, because someone is trying to sell one of [Eric]’s clone cards for $180.

All the code, files, materials, and everything needed to clone a Sound Blaster can be found in [Eric]’s GitHub, although there are a few open questions as to what’s going on in the Sound Blaster’s microcontroller. There’s a ‘secret’ 512-byte ROM on the die, and no one outside of an Intel NDA knows what it does. This could be used for a manufacturing test, but who knows. Other than that, there are a few features in the code that weren’t used, like previously unknown DSP commands, an ADPCM lookup table, and a routine that plays from SRAM without using DMA. It’s a deep dive into the inner workings of the most popular sound card of all time, and it’s quite simply amazing.

Manufacturing New Connectors For The Apollo Guidance Computer

June 18, 2019 by 20 Comments

The fiftieth anniversary of the Apollo 11 mission – the flight that first took man to the surface of the moon — is coming up. By the time this post is published, some YouTube channel will invariably be running a real-time-but-delayed-fifty-years live stream of all the mission events, culminating on the wee hours of July 20th where we wait hours for someone to figure out how to open the door.

[CuriousMarc] and space hardware collector [Jimmie Loocke] have a different type of anniversary in mind. They have an Apollo Guidance Computer sitting on a bed in a motel room, and they’re going to get it up and running by July 20th. That’s the plan, at least. This is no easy feat: the Apollo Guidance Computer looks like two 19-inch, 1U rack units, with no standardized connectors to talk to any other hardware. They’ve just figured out the hardest part of this build by making their own NASA-spec contacts. They can now connect external hardware to the AGC, probably for the first time in decades.

As it stands now, there are external ports on the gigantic bricks of aluminum enclosure that comprise the two AGC modules. These ports are just female pin headers, completely unlike any standard that can be found today. However, the folks at Samtec managed to build the male versions of these pin headers for this project. These pins fit the female sockets on one end, and are standard, square-shaped wire wrapped headers on the other. They are mounted in a milled plastic block, and after everything is wired up, [Marc] and [Jimmie] had a direct electrical connection to the Apollo Guidance Computer. The machine lives again.

There’s still a lot of work to do to get these bricks of computer up and running for the 20th, but this is fantastic progress. Already they’re single-stepping the AGC and running the P63 program that landed on the moon. Check out the video below.

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Adobe Neural Net Detects Photoshop Shenanigans

June 18, 2019 by 13 Comments

Photoshop can take a bad picture and make it look better. But it can also take a picture of you smiling and make it into a picture of your frowning. Altering images and video can of course be benign, but it can also have nefarious purposes. Adobe teamed up with researchers at Berkeley to see if they could teach a computer to detect a very specific type of photo manipulation. As it turns out, they could.

Using a Photoshop feature called face-aware liquify, slightly more than half of the people tested could tell which picture was the original and which was retouched to alter the facial expression. However, after sufficient training, Adobe’s neural network could solve the puzzle correctly 99% of the time.

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Morse Code Catches Google Swiping Lyrics

June 18, 2019 by 60 Comments

We think of Morse code in terms of dots and dashes, but really it’s a kind of binary code. Those symbols might as well be 0s and 1s or any other pair of characters. That attribute is exactly what led to a sting operation a music lyric site called Genius.com pulled on Google. At issue was a case of song lyrics that had allegedly been stolen by the search giant.

Song lyric sites — just like Google — depend on page views to make revenue. The problem is that in a Google search the lyrics appear on the search page, so there is no longer much incentive to continue to the song lyric site. That’s free enterprise for you, right? It is, but there was a problem. It appears that Google — or, according to Google, one of their partners — was simply copying Genius.com’s lyrics. How does Genius know the song lyrics were copied? According to news reports in the Wall Street Journal and other sources, they used Morse code.

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Making A Digital Clock A Little More Intuitive

June 18, 2019 by 19 Comments

Digital clocks are extremely useful and generally considered pretty easy to read. However, they can sometimes have rather arcane interfaces for setting the time and alarms. For [Michael Wessel], he noted that in the 1980s he had to routinely help his grandparents set their clocks for this very reason. That inspired his most recent project – a digital clock that’s intuitive to use.

Many digital clocks work in the same way, in which a digit of the time is set, before another button is pressed to cycle to the next digit. This can get confusing, so [Michael] went a different way. Instead, each digit can be cycled through using its own button, which can make things easier. It’s not readily apparent how one chooses to set the time, date, or alarm, but it’s an interesting take on how to create such an interface.

The clock relies on an Arduino Mega to run the show, with an RTC for timekeeping and a temperature sensor to boot. There’s also a sound sensor, which allows the alarms to be shut off with the clap of a hand or by shouting “STOP” at the alarm. Overall, it’s a tidy build with that hacker-favourite seven-segment aesthetic. Of course, you can take that very concept to its extremes, too. Video after the break.

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Tiny Tank Inspects Your Crawlspace

June 18, 2019 by 30 Comments

If you’ve got some drone or FPV part lying around, this is the build for you. It’s a remote controlled tank, with a camera and video transmitter, that’s only 65 mm x 40 mm x 30 mm in size. Why on Earth would you ever build something so small? You can look around in your crawlspace, I guess. Any way you look at, this thing is tiny.

The tank has traditional tank skid steering through two brushless motors. The battery is one cell, as that’s just about the largest battery you can put in a vehicle so small, and the camera is just off-the-shelf quadcopter stuff set into a 3D printed enclosure. There are a few LEDs for lights. Other than that, it’s just so tiny and so cute.

The builder behind this tank, [honnnest], put up a video going through the build and demonstrating what kind of video you can expect from a tank this small. It’s a bit fast for a tank, and that’s not even considering the scale effects, but if the chassis is 3D printed, you can always print a few reduction gears, too.

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Before Computers: Notched Card Databases

June 18, 2019 by 33 Comments

It is hard to remember that practical computers haven’t been around for even a century, yet. Modern computers have been around an even shorter period. Yet somehow people computed tables, kept ledgers, and even wrote books without any help from computers at all. Sometimes they just used brute force but sometimes they used little tricks that we’ve almost forgotten. For example, only a few of us remember how to use slide rules, but they helped send people to the moon. But what did database management look like in, say, 1925? You might think it was nothing but a filing cabinet and someone who knew how to find things in it. But there was actually a better system that had fairly wide use.

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