TechyMagThings

[Casey Bralla] got his hands on a Rockwell AIM 65 microcomputer, a fantastic example of vintage computing from the late 70s. It sports a full QWERTY keyboard, and a twenty character wide display complemented by a small thermal printer. The keyboard is remarkably comfortable, but doing software development on a one-line, twenty-character display is just not anyone’s idea of a good time. [Casey] made his own tools to let him write programs on his main PC, and transfer them easily to the AIM 65 instead.

Moving data wasn’t as straightforward in 1978 as it is today. While the Rockwell AIM 65 is a great machine, it has no disk drive and no filesystem. Programs can be written in assembler or BASIC (which had ROM support) but getting them into running memory where they could execute is not as simple as it is on modern machines. One can type a program in by hand, but no one wants to do that twice.

Fortunately the AIM 65 had a tape interface (two, actually) and could read and store data in an audio-encoded format. Rather than typing a program by hand, one could play an audio tape instead.

This is the angle [Casey]’s tools take, in the form of two Python programs: one for encoding into audio, and one for decoding. He can write a program on his main desktop, and encode it into a .wav file. To load the program, he sets up the AIM 65 then hits play on that same .wav file, sending the audio to the AIM 65 and essentially automating the process of typing it in. We’ve seen people emulate vintage tape drive hardware, but the approach of simply encoding text to and from .wav files is much more fitting in this case.

The audio encoding format Rockwell used for the AIM is very well-documented but no tools existed that [Casey] could find, so he made his own with the help of Anthropic’s Claude AI. The results were great, as Claude was able to read the documentation and, with [Casey]’s direction, generate working encoding and decoding tools that implemented the spec perfectly. It went so swimmingly he even went on to also make a two-pass assembler and source code formatter for the AIM, as well. With them, development is far friendlier.

Watch a demonstration in the video [Casey] made (embedded under the page break) that shows the encoded data being transferred at a screaming 300 baud, before being run on the AIM 65.

It’s one thing to learn about transmission lines in theory, and quite another to watch a voltage pulse bounce off an open connector. [Alpha Phoenix] bridges the gap between knowledge and understanding in the excellent videos after the break. With a simple circuit, he uses an oscilloscope to visualize the propagation of electricity, showing us exactly how signals travel, reflect, and interfere.

The experiment relies on a twisted-pair Y-harness, where one leg is left open and the other is terminated by a resistor. By stitching together oscilloscope traces captured at regular intervals along the wire, [Alpha Phoenix] constructs a visualization of the voltage pulse propagating. To make this intuitive, [Alpha Phoenix] built a water model of the same circuit with acrylic channels, and the visual result is almost identical to the electrical traces.

For those who dabble in the dark art of RF and radio, the real payoff is the demonstration of impedance matching in the second video. He swaps resistors on the terminated leg to show how energy “sloshes” back when the resistance is too high or too low. However, when the resistor matches the line’s characteristic impedance, the reflection vanishes entirely—the energy is perfectly dissipated. It really makes it click how a well-matched, low SWR antenna is crucial for performance and protecting your radio.

[Alpha Phoenix] is a genius at making physics visible. He even managed “film” a laser beam traveling at light speed.

[Tommy] at Oskitone has been making hardware synth kits for years, and his designs are always worth checking out. His newest offering Space Dice is an educational kit that is a combination vintage sci-fi space laser sound generator, and six-sided die roller. What’s more, as a kit it represents an effort to be genuinely educational, rather than just using it as a meaningless marketing term.

There are several elements we find pretty interesting in Space Dice. One is the fact that, like most of [Tommy]’s designs, there isn’t a microcontroller in sight. Synthesizers based mostly on CMOS logic chips have been a mainstay of DIY electronics for years, as have “electronic dice” circuits. This device mashes both together in an accessible way that uses a minimum of components.

There are only three chips inside: a CD4093 quad NAND with Schmitt-trigger inputs used as a relaxation oscillator, a CD4040 binary counter used as a prescaler, and a CD4017 decade counter responsible for spinning a signal around six LEDs while sound is generated, to represent an electronic die. Sound emerges from a speaker on the backside of the PCB, which we’re delighted to see is driven not by a separate amplifier chip, but by unused gates on the CD4093 acting as a simple but effective square wave booster.

In addition, [Tommy] puts effort into minimizing part count and complexity, ensuring that physical assembly does not depend on separate fasteners or adhesives. We also like the way he uses a lever assembly to make the big activation button — mounted squarely above the 9 V battery — interface with a button on the PCB that is physically off to the side. The result is an enclosure that is compact and tidy.

We recommend checking out [Tommy]’s concise writeup on the design details of Space Dice for some great design insights, and take a look at the assembly guide to see for yourself the attention paid to making the process an educational one. We love the concept of presenting an evolving schematic diagram, which changes and fills out as each assembly step is performed and tested.

Watch it in action in a demo video, embedded just below. Space Dice is available for purchase but if you prefer to roll your own, all the design files and documentation are available online from the project’s GitHub repository.

The common narrative around device design is that you can have repairability or a low price, but that they are inversely proportional to each other. Apple’s new budget MacBook Neo seems to attempt a bit of both.

Brittle snap-fit enclosures or glue can make a device pop together quickly during manufacture, but are a headache when it comes time to repair or hack it. Our friends at iFixit tore down the Neo and found it to be the most repairable MacBook since the 2012 unibody model. A screwed in battery, and modules for many of the individual components including the USB ports and headphone jack make it fairly simple to replace individual components. Most of those components are even accessible as soon as you pop the bottom cover instead of requiring major surgery.

As someone who has done a keyboard replacement on a 2010 MacBook, the 41 screws holding the keyboard in brought back (bad) memories. While this is a great improvement over Apple’s notoriously painful repair processes, we’re still only looking at an overall 6/10 score from iFixit versus a 10/10 from Framework or Lenovo.

The real story here is that these improvements from Apple were spurred by Right-to-Repair developments, particularly in the EU, that were the result of pressure from hackers like you.

If you want to push a Neo even further, how about water cooling it? If you’d rather have user-upgradeable RAM and storage too in a Mac, you’ve got to go a bit older.

Recently [ETA Prime] felt a bit underwhelmed by the raw performance of his MacBook Neo when it came to running for extended periods under full load, such as when gaming. Thus the obvious solution is to mildly over-engineer a cooling solution that takes care of issues like thermal throttling.

The Apple MacBook Neo with its repurposed iPhone 16 SoC seems to have leaned hard into answering the question whether a smartphone can be a good general purpose personal computer. Ignoring the lack of I/O, it’s overall not a bad SoC for a laptop, but like when you try to push the CPU and GPU on a smartphone, they do get pretty toasty. Due to the minimalistic cooling solution in the MacBook Neo it’ll easily hit the 105°C thermal throttle limit.

Technically the ‘heatsink’ for this laptop is the aluminium case, as the SoC is coupled via a thermal pad to the case. This doesn’t leave a lot of space and the case will heat soak pretty fast, while also making retrofitting a cooling solution a challenge.

Amusingly, replacing the existing thermal pad with a thin copper plate already massively reduced the thermal throttling of the A18 Pro SoC by about 20 degrees. In Geekbench 6 this bumped multi-core scores up by 9.7% and single-core by 15.2%. Definitely a promising glimpse at how much performance could still be extracted from this SoC.

For the next step a thermo-electric cooler (TEC) with built-in water cooling loop was used, which happened to be one of those overkill smartphone cooling systems that you’d stick to the back of the phone. Here the cooler was attached similarly, directly to the bottom aluminium of the case.

With this solution in place Geekbench 6 results mostly showed a solid bump for single-core results, while multi-core results showed diminishing returns. For Cinebench results this gave a 19% increase over stock cooling in multi-core and 23.5% for single-core.

Perhaps most interesting of all was that playing a video game for a while without thermal throttling meant framerates of over 80 FPS instead of hitting that thermal wall with 30 FPS. This shows just how much performance is left on the table due to the cooling choices for the system, even with this still rather inefficient cooling solution.

That said, this probably isn’t some kind of nefarious scheme by Apple, but rather the result of designing the thermal solution to not heat the case up to temperatures that are deemed to be unsafe or uncomfortable for the user. After all, if the case if the heatsink, then you don’t want to feel like you’re literally handling one. This is sadly the compromise when venting out hot air is deemed to be an unacceptable solution.

Laser Welding is apparently the new hotness, in part because these sci-fi rayguns masquerading as tools are really cool. They cut! They weld! They Julienne Fry! Well, maybe not that last one. In any case, perhaps feeling the need to cancel out that coolness as quickly as he possibly could, YouTuber [Wesley Treat] decided to make a giant version of his own head.

[Wesely] had previously been 3D scanned as part of the maker scans project, which you can find over on Printables. Those of you who really hate YouTubers, take note: finally you have something  to take your frustrations out on. [Wesely] takes that model into Blender to decimate and decapitate– fans of the band Tyr may wonder if the model questioned his sword–before feeding that head through an online papercraft tool called PaperMaker to generate cut files for his CNC. There are also a lot of welding montages interspersed there as he practices with the new tool. [Wesely] did first try out his new raygun on steel in a previous video, but even knowing that, he makes the learning curve on these lasers look quite scalable.

While we’re not likely to follow in [Wesely]’s footsteps and create our own low-poly Zardoz– Zardozes? Zardii?– using a papercraft toolchain and CNC equipment with sheet aluminum is absolutely a great idea worth stealing. It’s very similar to what another hacker did with PCBs— though that project was perhaps more reasonable in scale and ego.

We are no strangers to papercrafts that use actual paper here, either, having featured everything from model retrocomputers to fully-mobile strandbeasts. 

What did Elliot Williams and Al Williams read on Hackaday last week? Tune in and find out. After a bit of news, [Vik Oliver] chimes in with some deep PLA knowledge. Then the topic changed to pressure advance measurements, SDRs, making super-resolution PCBs with a fiber laser, and more.

Want to 3D print wire strippers? A robot arm? Or just make your own Z-80? Those hacks are in there, too.

For the long articles, we talked about old tech, including the :CueCat and the Iomega Zip Drive. Let us know if you had either one in the comments.

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Interesting Hacks of the Week:

• Direct Pressure Advance Measurement For Fast Calibration
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• Building A $50 SDR With 20 MHz Bandwidth
• Using A Fiber Laser To Etch 0.1 Mm PCB Traces
  • Laser Etching Printed Circuit Boards
  • Why Are You Still Making PCBs?
  • Supercon 2024: Quick High-Feature Boards With The Circuit Graver
• Build This Open-Source Graphics Calculator
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• The Most Intricate Of Freeform Digital Clocks
  • Bend It Like Bhoite: Circuit Sculptures Shatter The Bounds Of Flatland
• PicoZ80 Is A Drop-in Replacement For Everyone’s Favorite Zilog CPU
  • 770 Zilog Z80 :: Quicker, easier and cheaper to make your own chip!
  • Retrocomputing For $4 With A Z80

Quick Hacks:

• Elliot’s Picks:
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    • Hot Wire Strippers
  • Electric Motorcycles Don’t Have To Be Security Nightmares, But This One Was
  • Demonstrating Gray Codes With Industrial Display
  • 3D Printed Robot Arm Built For Learning Purposes
• Al’s Picks:
  • Arduino Code on My 8051: It’s More Likely Than You Think
  • Analog Video From An 8-Bit Microcontroller
  • A Candle-Powered Game Boy For Post-Apocalyptic Tetris

Can’t-Miss Articles:

• Retail Fail: The :CueCat Disaster
• From Zip To Nought: The Rise And Fall Of Iomega
  • Storage Media Forgotten