Powering Up A Pluggable Module From The 1948 IBM 604 Electronic Calculator

June 8, 2026 by Maya Posch 4 Comments

In that awkward transition phase between electromechanical accounting systems used in the 1940s and the introduction of fully digital computers we find systems such as the IBM 604 Electronic Calculator, advertised for accounting, calculating and engineering tasks. While not capable of complex instructions, loops and other advanced features, it did use an interesting modular architecture with easily swappable modules containing a vacuum tube and associated components. Recently [Ken Shirriff] took a poke at one of these and even powered it up.

This kind of pluggable system would become a staple of computer systems, as they enabled the use of modules or cards with specific functions that could be swapped and combined at will to increase system flexibility, lower costs and make repairs a snap. For the IBM 604 a total of about 1250 vacuum tubes were used, apparently all of which were found on these pluggable modules.

The module that [Ken] got his hands on has a thyratron tube, which is effectively a high current switch and rectifier. In the short demonstration video you can see it being used to switch a lamp on and off, with further details explained in the article.

Despite being rather limited in its functionality and limited by the punch card input and output speed, the IBM 604 was still a smashing commercial success with over 5600 units produced. A transistorized prototype version with 2200 transistors and 95% less power usage was created in 1954 that formed the basis for the IBM 608, the world’s first commercial all-transistorized calculator.

The 608 didn’t last too long, however, as at that point the breakneck pace of semiconductor technology meant that any newly released product was already obsolete by the time it hit the market. Despite this, fundamentals like pluggable modules would keep showing up over and over, ranging from the 1950s Bendix G-15 to even modern day systems, including PCs with pluggable RAM and expansion cards as well as mainframes where hot swapping of even entire CPU modules is just another feature.

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Revisiting Using AI Coding Assistants: You’re Holding It Wrong Edition

June 8, 2026 by Maya Posch 115 Comments

After scathing accusations of skimping on due diligence, as well as other feedback to my article on trying to use an ‘AI coding assistant’ for the first time, the only rational, academic response is to lick one’s wounds following a particularly bruising peer review and try to address the raised issues. Reality after all does not care about one’s feelings, and there may be more to this AI assistant technology that can be coaxed out with a more in-depth look.

To this end I’ll do my best to try and work through each raised point, criticism and accusation, to see what I – and perhaps others – can learn of this endeavor. Said points include the use of the wrong frontend – i.e. Copilot – and the wrong model – being Claude Haiku 4.5 – as well as the egregious flaw on my end of ‘prompting wrong’.

For the sake of due diligence the best frontend and models will be investigated for particular tasks, with finally the verbal minefield of ‘prompt engineering’ examined for industry-standard approaches.

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Ask Hackaday: How Do You Feel About Electronic Shelf Labels?

June 4, 2026 by Tom Nardi 151 Comments

Unless you’ve spent the last few years locked indoors and had all of your goods delivered to you — a not entirely implausible situation, given our audience — you’ve likely noticed the growing popularity of electronic shelf labels (ESLs). They’ve been a common sight in grocery stores like Aldi for some time, and major retailers such as Walmart and Home Depot have been expanding their use of the technology.

On the surface, it makes perfect sense. With electronic ink displays, you can create a price tag that looks enough like a paper label that the customer’s experience isn’t really any different, but the retailer doesn’t have to send somebody out to update the prices. Sure, the upfront cost is higher than a roll of sticky paper, but theoretically, the ESLs should pay for themselves thanks to the reduced labor costs.

It’s the sort of high-tech solution to a common problem that one of us would have come up with. If this were a decade ago, we wouldn’t have been surprised to see something like this get entered into the Hackaday Prize. It might have even won.

Now that the technology is becoming commonplace, there’s even more reason for hardware hackers to be interested in it. Since most of these tags will show whatever image you beam over to them via radio or infrared, we’ve seen a number of projects that repurpose second-hand tags as convenient data displays.

Rather than showing the price of milk, they can show the current price of Bitcoin. Or maybe you’d like to stick them up all over the house to display the weather forecast and your family calendar. They’ve been repurposed as badges at hacker cons, and at least one industrious hacker has used a discarded ESL to show an alert whenever a new episode of the Hackaday Podcast drops.

But not everyone is happy about ESLs. Recently, the United Food and Commercial Workers (UFCW) International Union released the results of a poll showing that most American consumers are opposed to ESLs, citing concerns that the technology would ultimately lead to higher prices.

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Know Your Food: Cheesemaking

June 1, 2026 by Jenny List 80 Comments

There’s a thing that people who grew up on farms all share: a connection with food production that isn’t some mystical rose-tinted woo from a TV chef, but instead a practical general knowledge from being there on the ground. A glance at a crop in a field and you immediately recognise what it is, if it’s ploughing time you’ll know the soil type, and there’s always either too little, or too much rain. For a given foodstuff you’ll know far too much about where it came from, because if your dad wasn’t involved in its production, the chances are someone he knew was. You take this for granted, after all doesn’t everyone have this general knowledge? Seemingly not.

Hackaday is not a cooking channel, but I know we’re all interested here in how things are made. Shouldn’t that also extend to what we eat? It’s fashionable to follow a back-to-nature line that all commercial foodstuffs are somehow over-processed junk, but without the requisite knowledge you’re flying blind there. To know both how common foodstuffs should be made, as well as how they are made industrially, should be an essential for everyone.

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Hunting Submarines Via Gravity Is A Tough Errand

May 27, 2026 by Zoe Skyforest 58 Comments

Among so many other technological advances, the Cold War saw the advent of the ballistic missile submarine. The concept was simple—pack enough nuclear warheads to destroy a small civilization into a compact metal tube, and then hide it underwater. The oceans would act as a cloak for your fleet of world-enders, and keep your enemies forever on their toes. A terrifying machine that could both start and end a war with the push of a button.

Most nation states are populated by humans with the will to live. Thus, there has been a great incentive to find ways to keep tabs on these sunken doombringers. Great efforts have gone into improving sonar and magnetic detection methods over the decades, which are the bread and butter of sub hunting to this day. However, military researchers have also explored the prospect of whether submarines could be detected via their effect on the gravitational field alone.

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Remember When Flash Drives Were Going To Make Your PC Faster?

May 26, 2026 by Zoe Skyforest 47 Comments

The 2000s was a decade of great change in the computer industry. The world had grown accustomed to corruptible floppy disks, blue screens of death, and achingly slow load times. In a few short years, all of that would change, as USB drives, better operating systems, and faster processors brought forth a new age of stability and speed.

Amidst this era of upheaval, Microsoft introduced a new technology. It was intended to increase performance on the cheap to a new generation of machines, but it would turn out to be little more than a gimmick that never really caught on. Let’s explore the easily-forgotten legacy of ReadyBoost.

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The Email Of The Future In 1986

May 24, 2026 by Jenny List 26 Comments

With so many online messaging services to choose from it’s almost as though the daddy of them all, email, has faded into the background as something you only use for more formal contacts. But it’s still the underpinning of much of the business world’s electronic communication and is likely to stay so for the foreseeable future. The BBC Archive takes us back to a time when email was relatively new, when in 1986 [Lesley Judd] takes a very chunky 1980s laptop on a plane from London to the Netherlands, and sends an email to her colleague at home using a payphone and an acoustic coupler.

There are so many of-their-era quirks in this film it’s difficult to pick, but little things like the aircraft still having smoking and non-smoking areas, there being no sign of a mobile telephone, or the payphone operating in Guilders rather than Euros make it from a different time. Perhaps most interesting though is the email system in use, because this isn’t an internet based service. Instead it’s using Telecom Gold, which was the UK telco BT’s online service offering to businesses, and part of the international Dialcom network. This was a commercial service which hung on until some time in the 1990s when the Internet finally displaced it.

The British writer L. P. Hartley used the phrase “The past is a foreign country; they do things differently there” as the opening sentence of one of his books, and the film below the break certainly brings that to mind. It’s a time that’s within reach, yet the changes in information technology over even the next decade or so would make the tech depicted not just obsolete but almost unrecognizable. Most of us today could sit at a 1996 laptop and send an email, but few of us would be as immediately at home with Telecom Gold.

It’s still possible to use an acoustic coupler today though.

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