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One of the most common issues with vintage computers is faulty RAM. For whatever reason, certain manufacturers and part numbers seem to fail at a much higher rate than others. Being able to test suspect RAM can be hugely helpful. This DRAM Tester supports a wide range of common parts – the 4116, 4164, 41256, 4332, 4132 and many more.

Sometimes the parts fail completely and it’s obvious that they are damaged. But in many cases, you’ll have intermittent faults or strange behaviour that comes and goes. Some software diagnostic cartridges can do RAM checks but if you regularly repair or test vintage computers, having a hardware RAM tester on hand can make the job a lot easier — especially if you’re unable to get software to load due to RAM issues.

With four different test modes, you can find out if there are faulty cells, issues with dynamic refresh, or intermittent faults. It can also be handy to test purchased RAM chips before installing them to make sure you’re not installing faulty parts! If you deal with any of these older dynamic RAM chips this tester will make a great addition to your toolkit.

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These educational books aren’t “books” in the traditional sense. They’re books made of circuit boards, with each “page” covering a useful reference circuit. The first two volumes cover DC Circuit Fundamentals and LEDs, Transistors and Oscillators. The pages are fully functional circuits with descriptions, and include fundamentals like Kirchhoff’s Current and Voltage Law, RC time constants and more.

This is a really neat way to learn about electronics fundamentals with circuits that are guaranteed to work; all you need is a USB-C power supply and a multimeter and/or oscilloscope to probe the circuits. These could be a great accessory to have around a hackerspace, or even in the science classroom! Hang them on the wall near the soldering station or design computers as a handy reference, or use them when teaching small gatherings of students who are discovering electronics for the first time.

The existing volumes are gorgeous gold and white on matte black, which gives them a premium look and feel. We’re looking forward to seeing more volumes released, hopefully covering increasingly advanced circuits!

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We are huge fans of retro computers here at Tindie, and the constant stream of amazing new tweaks and hacks for these classic machines never ceases to amaze us. This S-Video and Composite Mod … Thing for the VIC-20 improves the output quality of the composite video and adds an ultra-sharp S-Video output to boot! While the VIC-20 was a solid design, most televisions in the early 1980s simply didn’t have the ability to resolve fine edges and so the original VIC chip didn’t need to generate top-tier video output, it just had to be good enough to be usable.

As time wore on and TV technology vastly improved, the shortcomings of the original composite output stage from the VIC became more and more obvious. Fuzzy output, ringing on high frequencies leading to loss of definition, and poor contrast all added up to make the picture less than stellar. On a modern television, the VIC-20 looks… pretty sad, to be honest. But this board remedies that by retroactively applying high-quality circuit design and quality components to the output stage. The difference really is astounding:

Installation requires some soldering, but nothing too difficult. If in doubt, just wrangle the nearest hacker by offering cake and cookies in exchange for soldering. It’s possible to install the mod in such a way that it can be completely undone in case you want to return your VIC back to its original form, though we suspect few will want to!

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If you’re looking to build a wireless device with AI features to take advantage of the so-called AI On The Edge, you need reliable power, good wireless connectivity, and enough horsepower to do some or most of the processing on-device. This AI-On-The-Edge-Cam device is designed to specifically work with a particular software framework. The project initially used the generic ESP32-CAM devices, but they lacked hardware features that are required for typical applications, like battery and power management, Ethernet/PoE and camera backlighting.

Unlike typical applications, which might gather video data on a remote device and then submit those images to a powerful cloud server for processing and analysis, AI On The Edge moves some or all of that processing to the device itself, speeding up reaction times and allowing easy scalability. This kit comes with an OV2640 camera module, which can sample at up to 1630 x 1230 @ 15fps, or up to 60fps with CIF resolution.

USB-C allows for easy charging and programming, and an onboard Stemma QT connector adds easy I2C expansion. PoE support allows for permanent installation, but battery-powered applications are also possible. 4 RGB LEDs allow for camera backlight compensation. All in all, it’s a powerful little package with many possible applications!

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The Teensy 4.1 is famously powerful, with a 600MHz ARM Cortex-M7, a 64-bit floating point unit, gobs of flash and RAM (which are expandable!) and certain interfaces that are ideal for audio processing, like I2S and S/PDIF. This Programmable Guitar Pedal combines the intense processing power of the Teensy with a high-quality ADC and DAC audio chipset, the WM8960, to create the ultimate in customizable guitar effects pedals.

The Teensy Audio Library is a very well-written and easy-to-use audio processing library which is perfect for applications like this. The documentation includes a few examples of simple effects like Bitcrusher and Delay, and it’s amazing that each effect is only a hundred or so lines of code. There is even a GUI application to help you design and tweak the audio processing, so you can quite literally create just about any sound you can imagine. The possibilities are truly endless!

If you’re a guitar player and are willing to learn a bit about how the Teensy Audio Library works, this could become a key part of your pedal lineup. It’s designed to fit into a Hammond 1590B enclosure, a very popular enclosure for guitar pedals, so you can decorate it and make it uniquely your pedal. Check out the full listing page for all the details!

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It’s truly amazing how much power hackers have been able to squeeze out of the dual-core RP2040. Considering they are only Cortex-M0+ cores and not the more powerful M4 or M7 cores, generating signals like DVI and HDMI is simply amazing. This add-in card for the classic Apple ][ adds a digital video output which is significantly sharper and, of course, easier to use with modern displays and TVs.

It generates the video signal directly from the video RAM contents, and because it has total control, it can easily do 80-column output, alternative character sets and keyboard layouts. Because the communication is bidirectional, future expansion for the card could easily add features that modify RAM contents or snoop on the expansion bus. Already, a special firmware for the Apple 2e allows it to emulate a floppy drive!

Like a Pico, it has a USB-C connector for power and programming when not being used in the machine. Otherwise, it gets power from the Apple ][ and runs completely self-contained. The display emulates the classic Apple artifact colour look, though I’m sure it would be possible to convert the artifact colours into true, regular colour outputs — I wonder how that would look? If you’ve got an Apple ][ and don’t want to keep a classic CRT around for it, this is a great option to bring it into the 21st century.

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I2C devices are so commonplace nowadays that the hacker community has mostly coalesced around 2 connector types: JST SH and JST PH, known variously as Stemma, Qwiic, Stemma QT, Grove, etc. You can get an almost unlimited number of sensors and chip breakouts with these connectors, which can be daisy-chained for a large number of different sensors on the same bus. Well, this nifty I2C Shim for the Pico brings two JST SH connectors out for easy connection to Stemma QT/Qwiic peripherals.

The board is a nice, clean design. Staggered pads make for a tight, snug fit on the header pins coming from the Pico; however, you can also solder it directly to the Pico, or solder it to the header pins for a more secure, long-term connection. The board and connectors are slim enough that you could still mount the combination onto a PCB and solder the headers into place.

Having access to both I2C buses is a plus, as often you may want to connect two of the same sensor as many cannot have their I2C addresses reconfigured. This will allow you to do so without much hassle at all! If you use a lot of I2C peripherals, pick up a few of these and keep them with your hoard of Picos (come on, we all have a hoard of them) for quick and easy prototyping when needed!

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I’ve been looking for a nice, small, all-in-one power supply that can be powered using USB Power Delivery, and this portable DC power supply looks like a great fit for what I was imagining! It uses actual binding posts for power output, and has real knobs for adjusting power supply parameters. It has short-circuit protection and can provide up to 60W when powered from a suitable USB-C PD charger.

For something that is portable and simple to use, it doesn’t need to have the same accuracy as my Fluke benchtop power supply! It just needs to have basic 1% accuracy at least, and be good enough for quick hacks on the go or for a mobile lab bag. Most phone chargers nowadays are USB-C Power Delivery enabled, and can output at least 15V if not 20V. So being able to use something you already have on hand is a bonus!

The second USB-C port allows UART connection to the CH552 microcontroller inside. This allows you to do some basic data collection, which is a nice touch, but it also allows you to reprogram the firmware. If you want, you can spend some time carefully calibrating the supply by changing the constants in the firmware to adjust your individual unit. This option, plus the general ease of use, means it will almost certainly find use in your lab!

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Many classic Macintosh machines end up suffering from failed power supply boards. There are many different reasons for this, but primarily, these computers are now well over 35 years old and power supplies, like all components, have a rated useful life. While we’ve seen adapter boards that convert from ATX to the power connector on classic Macs, this ATX+VGA module replacement goes a step beyond and adds a Raspberry Pi Pico to give you VGA out!

It’s not clear from the description what the RCA connector on the right is for — we’re thinking possibly composite output, as audio is still handled by the motherboard. There are also two JST headers on the board, which look like they are possibly designed to drive cooling fans. In either case, we imagine documentation will improve over time, as these are hot off the press and are ready for users to put them through their paces!

It’s suggested that you could use one of the PicoATX DC supplies to make a very compact and modern replacement, and this seems like a great idea. This could also be an exceptionally useful tool for someone who often does repairs on these machines — you could easily unplug the built-in supply, connect this one with a VGA monitor pre-connected, and you can be testing with modern, reliable components in seconds.

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If you’re anything like me, any time you need 50 SMD resistors you buy 500 for the quantity discount. Same for SMD parts of all kinds! So I end up with tapes that have random amounts on them. I’m not organized enough to keep track on each reel, and I often forget which reel was used for which project. But the ReelTrack is a neat little gadget to make counting SMD parts a snap!

Keeping track of your inventory of parts can be a chore, so having a tool like this to make the job just that little bit easier is great. The slider on the back allows tapes of varying widths, and the two buttons on the front allow you to zero the count and select the pitch of the devices on the tape. Then you pull the tape through and let the machine do the counting. It has a spot for a lanyard loop, so it could be a great tool for someone working on a PCB manufacturing floor.

It’s USB-C powered, so to make it mobile, all you’d need is a small USB battery pack. As to how it actually does the counting – we can’t tell from the listing, but based on the presence of the LED in the front, we assume it’s using either the sprocket holes or just the contrast between the devices and the rest of the tape to get optical data. In any case, if you do a lot of DIY PCB assembly, it would make a great addition to your lab!

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