2025 One-Hertz Challenge: HP Logic Probe Brought Into The Future

[Robert Morrison] had an ancient HP 545A logic probe, which was great for debugging SMT projects. The only problem was that being 45 years old, it wasn’t quite up to scratch when it came to debugging today’s faster circuitry. Thus, he hacked it to do better, and entered it in our 2025 One Hertz Challenge to boot!

[Robert’s] hack relied on the classic logic probe for its stout build and form factor, which is still useful even on today’s smaller hardware. Where it was lacking was in dealing with circuits running at 100 MHz and above. To rectify this, [Robert] gave the probe a brain transplant with a Sparkfun Alorium FPGA board and a small display. The FPGA is programmed to count pulses while measuring pulse widths and time, and it then drives the display to show this data to the user. There’s also a UART output, and [Robert] is actively developing further logic analyzer features, too.

You might be questioning how this project fits in the One Hertz Challenge, given it’s specifically built for running at quite high speeds. [Robert] snuck it in under the line because it resamples and updates the display on a once-a-second basis. Remember, as per the challenge site—”For this challenge, we want you to design a device where something happens once per second.” We’re giving you a lot of leeway here!

Often, old scopes and probes and other gear are really well built. Sometimes, it’s worth taking the best of the old physical hardware and combining it with modern upgrades to make something stout that’s still useful today. Meanwhile, if you’re cooking up your own neo-retro-logic probes, don’t hesitate to notify the tipsline!

Will HP Create A Carfax System For PCs?

When buying used cars there are plenty of ways to check on their history. In many countries there are systems, like Carfax for parts of North America and Europe, that can provide crash history in some situations and alert a potential buyer of hidden damage. Not so for computers, where anyone can run an intensive mining, gaming, rendering, or AI application for years on hardware which might not otherwise show any outward signs of heavy use. And that’s just for hard use; there’s all kinds of other ways of damaging hardware. HP is hoping to solve this problem with a PC history report of sorts.

Aimed at the enterprise or business arena, where companies tend to follow replacement schedules for laptops and other hardware which might get discarded before reaching a true end-of-life, HP is suggesting adding a data recorder at the firmware level of some computers. This software would monitor the computer’s temperatures, SSD wear, and other telematics on the computer and store a record that could be viewed by a potential buyer when the IT department is ready to take them out of service. And, since it’s 2025, HP is also claiming that this system needs and uses an AI of some sort.

Although HP is billing this as a way to improve sustainability and limit e-waste, we’d theorize that even with a report like this available, the economic gain of a program like this would be marginal at best. While the idea of giving each decommissioned laptop a clean bill of health is noble, it’s hard to imagine overworked IT staff carefully curating device histories when most used enterprise machines are already sold by the pallet.

HP is also proposing something that sounds a lot like Intel’s Management Engine, which we’re not too thrilled about around here. And also keep in mind that this is a company that has failed to innovate in any industry-leading way for as long as we can remember so we won’t expect this system to be widely adopted anytime soon.

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Hackaday Links: March 16, 2025

“The brickings will continue until the printer sales improve!” This whole printer-bricking thing seems to be getting out of hand with the news this week that a firmware update caused certain HP printers to go into permanent paper-saver mode. The update was sent to LaserJet MFP M232-M237 models (opens printer menu; checks print queue name; “Phew!) on March 4, and was listed as covering a few “general improvements and bug fixes,” none of which seem very critical. Still, some users reported not being able to print at all after the update, with an error message suggesting printing was being blocked thanks to non-OEM toner. This sounds somewhat similar to the bricked Brother printers we reported on last week (third paragraph).

Continue reading “Hackaday Links: March 16, 2025”

A Modern Battery For A Classic Laptop

Aside from their ability to operate fairly well in extreme temperatures, lead-acid batteries don’t have many benefits compared to more modern battery technology. They’re heavy, not particularly energy dense, have limited charge cycles, and often can’t be fully discharged without damage or greatly increased wear. With that in mind, one can imagine that a laptop that uses a battery like this would be not only extremely old but also limited by this technology. Of course, in the modern day we can do a lot to bring these retro machines up to modern standards like adding in some lithium batteries to this HP laptop.

Simply swapping the batteries in this computer won’t get the job done though, as lead-acid and lithium batteries need different circuitry in order to be safe while also getting the maximum amount of energy out. [CYUL] is using a cheap UPS module from AliExpress which comes with two 18650 cells to perform this conversion, although with a high likelihood of counterfeiting in this market, the 18650s were swapped out with two that were known to be from Samsung. The USB module also needs to be modified a bit to change the voltage output to match the needs of the HP-110Plus, and of course a modernized rebuild like this wouldn’t be complete without a USB-C port to function as the new power jack.

[CYUL] notes at the end of the build log that even without every hardware upgrade made to this computer (and ignoring its limited usefulness in the modern world) it has a limited shelf life as the BIOS won’t work past 2035. Hopefully with computers like this we’ll start seeing some firmware modifications as well that’ll let them work indefinitely into the future. For modern computers we’ll hope to avoid the similar 2038 problem by switching everything over to 64 bit systems and making other software updates as well.

[Wills] and his purple DIY sorting hat

From Felt To Fate: Building Your Own Sorting Hat

Ever wondered how it feels to have the Sorting Hat decide your fate? [Will Dana] wanted to find out, so he conjured a bit of Hogwarts magic, and crafted a fully animatronic Sorting Hat from scratch. In the video below, he covers every step of bringing this magical purple marvel to life—from rapid joystick movements to the electronics behind it all.

The heart of the project is two 9g servos—one actuates the mouth, and the other controls the eyebrows—powered by an ESP32 microcontroller. Communication between two ESP32 boards ensures smooth operation via the ESP-NOW protocol, making this a wireless wonder. The design process involved using mechanical advantage to solve jittery servo movements, a trick that will resonate with anyone who’s fought with uncooperative motors.

If animatronics or themed projects excite you, Hackaday has covered similar builds, from a DIY BB-8 droid to a robot fox.

Continue reading “From Felt To Fate: Building Your Own Sorting Hat”

You Can Run BASIC On An Old HP 4592 Protocol Analyzer

What do you do when you find an ancient piece of test gear and want to have fun? Well, you can always try getting BASIC running on it, and that’s precisely what [David Kuder] did.

The HP4952A Protocol Analyzer actually looks a lot like an old computer, even if it was never meant for general-purpose use. The heart of the machine is a Zilog Z80 CPU, though, so it shares a lot in common with microcomputers of its era.

Among other hacks, [David] worked to get Microsoft Basic-80 running on the machine. Initially, he was only able to get it up and running on the display, with no way to read the keyboard, disk, or access the serial port. Eventually, by diving into the nitty-gritty of the machine, he was able to at least get the keyboard working along with some basic BASIC programs. Usable memory is just 8KB, but you can do a fair bit with that when you’ve only got a 32×16 display for output anyway!

It’s a neat hack and one that was extendable to the HP4957A as well. We’ve seen similar machines on these pages before, too! If you’ve got your own neat retro hacks on the boil, don’t hesitate to drop us a line!

[Thanks to Christopher Zell for the tip!]

Modern Microcontroller Boosts Classic Logic Analyzer To New Heights

[Ted Fried] recently found a beautiful HP 1600A/1607A logic analyzer set. State of the art in 1975, it looks like glorious Space Age equipment today. He decided to hook it up some modern gear to put it through its paces.

Wanting to give the equipment a proper shakedown, he enlisted a Teensy 4.1 to spit a deluge of logic at the HP unit. The microcontroller was tasked with generating 32 data signals along with two clock outputs to give the analyzer plenty to analyze. The HP 1600A handled this no problem, so [Ted] kept tinkering.

His next feat was to explore the addressable “MAP” function of the unit, which allowed writing to the 64×64 pixel display. The Teensy 4.1 was easily able to send images to the display, but [Ted] isn’t stopping there. He’s got plans to do the usual thing and get Bad Apple going on the hardware.

Getting a logic analyzer to analyze logic isn’t much of a hack, sure. But it’s instructive of how to approach working with such hardware. If you want to spit a bunch of logic out fast, a Teensy 4.1 is a great choice because it’s got a ton of IO and a ton of clock cycles to tickle it with.

We enjoyed seeing this old piece of hardware light up the phosphors once more. If you’ve got your own projects going on with classic bits of HP test gear, don’t hesitate to let us know!