Rescuing The Data On A 1960s LGP-21 Computer’s Disk Memory

April 25, 2026 by Maya Posch 36 Comments

One of the nice things about magnetic storage is that as long as the magnetic layer remains intact, the data it contains should stay readable pretty much indefinitely. That raises the prospect of recovering data from really old computer systems featuring magnetic memory, such as the 63-year old LGP-21 that [David Lovett] of Usagi Electric is currently restoring. Its magnetic memory disk is nothing amazing by modern standards, but after initial testing it seems to spin up and read data just fine, raising the question of what was left on the drive when it was last used, meaning what was in memory at the time.

The read/write head side of the LGP-21's magnetic memory. (Credit: Usagi Electric, YouTube) — The read/write head side of the LGP-21’s magnetic memory. (Credit: Usagi Electric, YouTube)

Non-invasive data recovery here involves writing a program that will simply read the entire disk from beginning to end. Tracks 0 and 1 were found to be unreadable due to some kind of hardware issue, but track 2 could be backed up by looking at the output on the CRT, thus providing a track to use. Fascinatingly the LGP-21’s memory disks uses interleaved tracks to reduce the number of read/write heads as part of the overall cost-saving measures relative to the more expensive LGP-30. As you might expect, this slows down memory access a lot over its big brother.

Before any recovery attempt could begin, the Flexowriter typewriter that forms the user interface to the computer had to be given some serious maintenance, along with a few other components like a switch and the paper tape reader. This restored the ability to even properly enter data and receive output instructions.

The subsequent effort to recover the stored data involved a bootstrap program that got loaded into memory, after which the remainder of the program was loaded from paper tape. Following this everything worked swimmingly, though with the caveat that with not even a floppy drive to use, the raw hexadecimal data was hammered out on paper with the Flexowriter over the course of 1.5 hours.

This data will now be scanned in and OCR-ed into something that can hopefully be easily analyzed. Hopefully we’ll know before long what this system was last used for.

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From Zip To Nought: The Rise And Fall Of Iomega

March 24, 2026 by Zoe Skyforest 101 Comments

If you were anywhere near a computer in the mid-to-late 1990s, you almost certainly encountered a Zip drive. That distinctive purple peripheral, with its satisfying clunk as you slotted in a cartridge, was as much a fixture of the era as beige tower cases and CRT monitors. Iomega, the company behind it, went from an obscure Utah outfit to a multi-billion-dollar darling of Wall Street in the span of about two years. And then, almost as quickly, it all fell apart.

The story of Iomega is one of genuine engineering innovation and the fickle nature of consumer technology. As with so many other juggernauts of its era, Iomega was eventually brought down by a new technology that simply wasn’t practical to counter.

The House That Bernoulli Built

Iomega was founded in Utah, in 1980, by Jerome Paul Johnson, David Bailey, and David Norton. The company soon developed a novel approach to removable magnetic storage based on the Bernoulli effect. The Bernoulli Box arrived in 1982, which was a drive relying on PET film disks spun at 1500 RPM inside a rigid, removable cartridge. The airflow generated by the spinning disk pulled the media down toward the read/write head thanks to the eponymous Bernoulli effect. While spinning, the disk would float a mere micron above the head surface on a cushion of air. If the power cut out or the drive otherwise failed, the disk simply floated away from the head rather than crashing into it—a boon over contemporary hard drives for which head crashes were a real risk. The Bernoulli Box made them essentially impossible. Continue reading “From Zip To Nought: The Rise And Fall Of Iomega” →

How Graphene May Enable The Next Generations Of High-Density Hard Drives

June 23, 2021 by Maya Posch 30 Comments

After decades of improvements to hard disk drive (HDD) technology, manufacturers are now close to taking the next big leap that will boost storage density to new levels. Using laser-assisted writes, manufacturers like Seagate are projecting 50+ TB HDDs by 2026 and 120+ TB HDDs after 2030. One part of the secret recipe is heat-assisted magnetic recording (HAMR).

One of the hurdles with implementing HAMR is finding a protective coating for the magnetic media that can handle this frequent heating while also being thinner than current coatings, so that the head can move even closer to the surface. According to a recent paper by N. Dwivedi et al. published in Nature Communications, this new protective coating may have been found in the form of sheets of graphene.

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Your Next Wearable May Not Need Electricity

November 17, 2017 by Kristina Panos 9 Comments

What if you could unlock a door with your shirtsleeve, or code a secret message into your tie? This could soon be a thing, because researchers at the University of Washington have created a fabric that can store data without any electronics whatsoever. The fabric can be washed, dried, and even ironed without losing data. Oh, and it’s way cheaper than RFID.

By harnessing the ferromagnetic properties of conductive thread, [Justin Chen] and [Shyam Gollakota] have proved the ability to store bit strings and 2D images through magnetization. The team used an embroidery machine to lay down thread in dense strips and patches, and then coded in ones and zeros by rubbing the threads with N and S neodymium magnets.

They didn’t use anything special, either, just this conductive thread, some magnets, and a Nexus 5 to read the data. Any phone with a magnetometer (so, most of them) could decode this type of binary data. The threads stay reliably magnetized for about a week and then begin to weaken. However, their tests proved that the threads can be re-magnetized over and over.

The team also created 2D images with magnets on a 9-patch made of conductive fabric. The images can be decoded piecemeal by a single magnetometer, or all at once by an array of them. Finally, the team made a glove with a magnetized patch of thread on the fingertip. They were able to get the phone to recognize six unique gestures with 90% accuracy, even with the phone tucked away in a pocket. See it in action in their demo video after the break.

Magnetic memory is certainly not a new concept. But for the wearable technology frontier, it’s a novel one.

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