An Amstrad PCW For The 21st Century

If you were a computer-mad teen in the late 1980s, you were probably in the process of graduating from an 8-bit machine to a 16-bit one, maybe an Amiga, or an Atari ST. For the first time though you might not have been the only computer owner in your house, because there was every chance your parents might have joined the fun with a word processor. Maybe American home offices during this period might have had PC clones, but for Brits there was every chance that the parental powerhouse would have been an Amstrad PCW.

Amstrad were the masters of packaging up slightly outdated technology for electronic consumers on a budget, and the PCW was thus a 1970s CP/M machine for the 1980s whose main attraction was that it came with monitor and printer included in the price. [James Ots]’ parents had one that interested him enough that  he has returned to the platform and is documenting his work bringing it up to date.

It was the most recent progress in booting into CP/M from an SD card by hijacking the printer ROM that caught our eye, but reading all the build logs that is only the tip of the iceberg. He’s connected another monitor, made a joystick port and a soundcard, and added a memory upgrade to his PCW. Most of these machines would have only been used with the bundled word processor, so those are real enhancements.

We’ve featured quite a few projects involving Amstrad’s CPC home computers, such as this one with a floppy emulator. Amstrad are an interesting company for followers of consumer electronics of the ’70s and ’80s, they never had the out-there tech wackiness of their great rival Sinclair but their logo could be found on an astonishing variety of appliances. The “AMS” in Amstrad are the initials of the company founder [Alan Sugar], who is rather better known in 2017 as the British host of The Apprentice. It is not known whether he intends to lead the country.

Quick and Easy Solar Hot Air Balloon

[Becky Stern] likes to harness the power of the Sun. Most of us will immediately think of solar cells and other exotic solar energy techniques. But [Becky] shows how to make a hot air balloon using nothing but tape and garbage bags.

The idea is quite simple. You form a large envelope from black trash bags and fill it with air. Becky does that by just running with it, tying it off, and topping off with a little manual blowing. Once the sun heats the black bag, it floats.

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Scratchbuilt Cryptex Would Make Da Vinci Weep

Here’s a fun fact, the kind of thing that you might (but we definitely did not) find out when writing a blog post: Dan Brown actually made up the cryptex for his book, The Da Vinci Code. We therefore have Mr Brown, with a bit of help from the filmmakers over at Sony, to thank every time we see somebody make their own version. To follow that line of logic to its conclusion, we believe you’ll agree that the following is without question the greatest thing Dan Brown has ever done in his life.

Created by [Stephen Peduto] as a ring box for an exceptionally lucky young lady, it required an estimated 127 hours to complete over the course of two months. From the incredible job [Stephen] did photographing and documenting the build, we don’t doubt it for a second. Expertly combing milled aluminum and lathe-turned bocote wood, this has got to be the most gorgeous ring “box” ever made.

Frankly, it’s hard to do justice to what [Stephen] has created in so short a space, and you really should browse through the 140+ images in his gallery. But the short version is that after some furious white board sketching, [Stephen] moved over to AutoCAD and then SolidWorks to design all the parts which would eventually get machined out of aluminum. As a very clever touch, he wisely added 17° slop in the locking mechanism so that the recipient wouldn’t fumble too much at the big moment.

When the machining was all said and done, [Stephen] then switched over to the woodworking part of the project. Rather than numbers or letters for a combination, this cryptex uses the grain pattern in the turned piece of wood. This gives the final product a more organic feel, while at the same time avoiding the head-scratching problem of getting the characters printed or engraved into the wheels.

Towards the end of construction there was a worrying moment when the newly made wooding rings warped so badly that the aluminum inserts would no longer fit. As a last resort, the rings were placed in a box with a humidifier for a week and slowly worked back into shape. [Stephen] says he’s still surprised it worked.

Even if some may argue that a cryptex is nothing but a prettied-up bike lock, people sure do love them. We’re no stranger to high quality cryptex builds here, though even mere mortals can play along if they’ve got a well calibrated 3D printer.

Pull Passwords Out of Silicon

[q3k] got tipped off to a very cool problem in the ongoing Pwn2Win capture-the-flag, and he blew it out of the water by decoding the metal interconnect layers that encode a password in a VLSI IC. And not one to rent someone else’s netlist extraction code, he did it by writing his own.

The problem in the Pwn2Win CTF came in the form of the design files for a hypothetical rocket launch code. The custom IC takes an ASCII string as input, and flips a pin high if it matches. Probably the simplest way to do this in logic is to implement a shift register that’s long enough for the code string’s bits, and then hard-wire some combinatorial logic that only reads true when all of the individual bits are correct.

(No, you don’t want to implement a password-checker this way — it means that you could simply brute-force the password far too easily — but such implementations have been seen in the wild.)

Anyway, back to our story. After reversing the netlist, [q3k] located 320 flip-flops in a chain, suggesting a 40-byte ASCII code string. Working backward in the circuit from the “unlocked” pin to the flip-flops, he found a network of NOR and NAND gates, which were converted into a logic notation and then tossed into Z3 to solve. Some cycles later, he had pulled the password straight out of the silicon!

This looks like a really fun challenge if you’re into logic design or hardware reverse engineering. You don’t have to write your own tools to do this, of course, but [q3k] would say that it was worth it.

Thanks [Victor] for the great tip!
Featured image by David Carron, via Wikipedia.

Hackaday Prize Entry: Arduino Video Display Shield

The Arduino is the standard for any introduction to microcontrollers. When it comes to displaying video, the bone stock Arduino Uno is severely lacking. There’s just not enough memory for a framebuffer, and it’s barely fast enough to race the beam. If you want video from an Arduino, it’s either going to be crappy, or you’re going to need some magic chips to make everything happen.

[MagicWolfi]’s 2017 Hackaday Prize entry consists of an video display shield that would be so easy to use that, according to the project description, it could be a substitute for the classic Blink sketch.

The project centers around the VLSI VS23S010D-L chip, which packs 1 Megabit SPI SRAM with serial and parallel interfaces. An integrated video display  sends the composite video signal to display, with the mode depending on how many colors and what resolution is desired: for instance, at 640×400 you can display 16 colors. As he describes it, not 4K video but definitely Joust. The chip expects 3.3 V logic so he made use of a MC74LVX50 hex buffer to tailor the Arduino’s 5 V. Currently he’s working on revision two of the shield, which will include SPI flash memory.

You can follow along with the project on or the current shield design can be found in [MagicWolfi]’s GitHub repository.

Coffee, Conspiracy, and Citizen Science: An Introduction to Iodometry

I take coffee very seriously. It’s probably the most important meal of the day, and apparently the largest overall dietary source of antioxidants in the United States of America. Regardless of whether you believe antioxidants have a health effect (I’m skeptical), that’s interesting!

Unfortunately, industrially roasted and ground coffee is sometimes adulterated with a variety of unwanted ‘other stuff’: corn, soybeans, wheat husks, etc. Across Southeast Asia, there’s a lot of concern over food adulteration and safety in general, as the cost-driven nature of the market pushes a minority of vendors to dishonest business practices. Here in Vietnam, one of the specific rumors is that coffee from street vendors is not actually coffee, but unsafe chemical flavoring agents mixed with corn silk, roasted coconut husks, and soy. Local news reported that 30% of street coffee doesn’t even contain caffeine.

While I’ve heard some pretty fanciful tales told at street side coffee shops, some of them turned out to be based on some grain (bean?) of truth, and local news has certainly featured it often enough. Then again, I’ve been buying coffee at the same friendly street vendors for years, and take some offense at unfounded accusations directed at them.

This sounds like a job for science, but what can we use to quantify the purity of many coffee samples without spending a fortune? As usual, the solution to the problem (pun intended) was already in the room:

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Mechanical Marvel Trades Courage for Chocolate

When we see what [Jason Allemann] does with LEGO, we wonder why more one-offs aren’t made this way. This time he’s made a Halloween mechanical marvel that will surely scare more kids than anything else they’ll encounter on their rounds — so much so that many may even decline the chocolate it dispenses. Who wouldn’t when to get it you have to reach over an animatronic skeleton hand that may grab you while a similarly mechanized spider may lunge onto your hand.

The chocolate dispensing, the hand and the spider are all animated using four motors, a LEGO Mindstorms EV3 brick to control them, and a touch sensor. When a kid presses a pumpkin attached to the touch sensor, the next chocolate candy is lowered by gravity onto a conveyor belt and carried forward to the awaiting child. That much is automatic. At the discretion of [Jason] and his partner [Kristal], using an infrared remote control and sensor, they can activate the skeleton hand and the lunging spider at just the right moment. We’re just not sure who they’ll choose to spare. It is Halloween after all, and being scared is part of the fun, so maybe spare no one? Check out the video below and tell us if you’d prefer just the treat, or both the trick and treat.

We do have to wonder if there’s any project that can’t benefit from LEGO products, even if only at the prototype stage or to help visualize an idea. As a small sample, [Jason]’s also made a remote-controlled monowheel and an actual working printer along with a Morse key telegraph machine to send it something to print.

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