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A brief history of defragging

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When the first Macs with internal hard disks started shipping in 1987, they were revolutionary. Although they still used 800 KB floppy disks, here at last was up to 80 MB of reliable high-speed storage. It’s worth reminding yourself of just how tiny those capacities are, and the fact that the largest of those hard disks contained one hundred times as much as each floppy disk. By the 1990s, with models like the Mac IIfx, internal hard disks had doubled in capacity, and reached as much as 12 GB at the end of the century.

Over that period we discovered that hard disks also needed routine maintenance if they were to perform optimally, and all the best users started to defrag their hard disks.

Consider a large library containing tens or even hundreds of thousands of books. Major reference works are often published in a series of volumes. When you need to consult several consecutive volumes of such a work, how they’re stored is critical to the task. If someone has tucked each volume away in a different location within the stack, assembling those you need is going to take a long while. If all its volumes are kept in sequence on a single shelf, that’s far quicker. That’s why fragmentation of data has been so important in computer storage.

The story of defragging on the Mac is perhaps best illustrated in the rise and fall of Coriolis Systems and iDefrag. Coriolis was started in 2004, initially to develop iPartition, a tool for non-destructive re-partitioning of HFS+ disks, but its founder Alastair Houghton was soon offering iDefrag, which became a popular defragging tool. This proved profitable until SSDs became more widespread and Apple released APFS in High Sierra, forcing Coriolis to shut down in 2019, when defragging Macs effectively ceased.

All storage media, including memory, SSDs and rotating hard disks, can develop fragmentation, but most serious attention has been paid to the problem on hard disks. This is because of their electro-mechanical mechanism for seeking to locations on the spinning platter they use for storage. To read a fragmented file sequentially, the read-write head has to keep physically moving to new positions, which takes time and contributes to ageing of the mechanism and eventual failure. Although solid-state media can have slight overhead accessing disparate storage blocks sequentially, this isn’t thought significant and attempts to address that invariably have greater disadvantages.

Fragmentation on hard disks comes in three quite distinct forms: file data across most of the storage, file system metadata, and free space. Different strategies and products have been used to tackle each of those, with varying degrees of success. While few doubt the performance benefits achieved immediately after defragging each of those, little attention has been paid to demonstrating more lasting benefits, which remain more dubious.

Manually defragging HFS+ hard disks was always a questionable activity, as Apple added background defragmentation to Mac OS X 10.2, released two years before Coriolis was even founded. By El Capitan and Sierra that built-in defragging was highly effective, and the need for manual defragging had almost certainly become a popular myth. Neither did many consider the adverse effects on hard disk longevity of those intense periods of disk activity.

techtoolpro1999

The second version of TechTool Pro in 1999 offered a simplified volume map for what it termed optimisation, offering the options to defragment only files, or the whole disk contents including free space.

techtoolpro2000

By the following year, TechTool Pro was paying greater attention to defragging file system metadata, here shown in white. This view was animated during the process of defragmentation, showing its progress in gathering together all the files and free space into contiguous areas. TechTool Pro is still developed and sold by MicroMat, and now in version 20.

speeddisk2001

A similar approach was adopted by its competitor Speed Disk, here with even more categories of contents.

drivegenius2010

By 2010, my preferred defragger was Drive Genius 3, shown here working on a 500 GB SATA hard disk, one of four in my desktop Mac; version 6 is still sold by Prosoft. One popular technique for defragmentation with systems like that was to keep one of its four internal disks empty, then periodically clone one of the other disks to that, and clone it back again.

diskwarrior2000

Alsoft’s DiskWarrior is another popular maintenance tool, shown here in 2000. This doesn’t perform conventional defragmentation, but restructures the trees used for file system metadata, and remains an essential tool for anyone maintaining HFS+ disks.

Since switching to APFS on SSDs several years ago, I have missed defragging like a hole in the head.



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chrisrosa
3 days ago
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San Francisco, CA
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YouTube gets Apple Vision Pro app Juno kicked from App Store

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Despite a lack of first-party YouTube clients on Apple Vision Pro, YouTube has prompted Apple to remove Juno from the App Store, citing vague guideline violations.

Search screen showing 'No Results' for YouTube, with options for Apple Vision or iPhone & iPad apps. Background with snowy landscape and trees.
YouTube doesn't offer a client for Apple Vision Pro

Juno was a third-party YouTube client built for Apple Vision Pro by Cristian Selig of Apollo fame. The app was a basic web view for YouTube that didn't go out of its way to alter content beyond aesthetics to make the app appear visionOS native.

Despite that, YouTube has pushed Apple to remove Juno from the App Store with no clarification or discussion. Selig shared the removal via a blog post.


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chrisrosa
8 days ago
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San Francisco, CA
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How the Hugely Acclaimed Shōgun TV Series Makes Translation Interesting

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Many of us grew up seeing hardback copies of Shōgun on various domestic bookshelves. Whether their owners ever actually got through James Clavell’s famously hefty novel of seventeenth-century Japan is open to question, but they may well have seen the first television adaptation, which aired on NBC in 1980. Starring Richard Chamberlain and Toshiro Mifune (and narrated by Orson Welles), that ten-hour miniseries offered an unprecedentedly cinematic experience to the home viewers of America, presenting them with things they’d never before seen on television — and things they’d never heard on television, not least numerous lines delivered in untranslated Japanese.

The idea, according to screenwriter Eric Bercovici, was to put the viewers in the shoes of Chamberlain’s protagonist John Blackthorne, an English ship pilot marooned in Japan with no knowledge of the local language. During the show’s run, newspapers printed glossaries of the Japanese words most important to the story. The second adaptation of Shōgun, which aired earlier this year on FX, does things differently. For one thing, it makes use of those helpful devices known as subtitles, which over the past four and a half decades have become not just accepted but demanded by Western audiences (even for productions in their own language).

This choice, as Evan “Nerdwriter” Puschak says in his video on the new Shōgun, “lets us into the minds and conversations of the Japanese characters,” much like the omniscient narration of Clavell’s novel. Puschak highlights how the series “uses the act of translation to explore the possibilities and limitations of communication across cultures and communication, period.” One notable example is its portrayal of the various bilingual characters who interpret for Blackthorne, each of whom does so differently according to his or her motivations. The 1980 Shōgun also had a few such scenes, but their dramatic irony was inaccessible to monolingual viewers.

Even if you speak both English and Japanese, you know how little protection that really offers against cultural misunderstandings. The new Shōgun’s dramatization of that truth has surely done its part to win the show more Emmy awards than any other single season of television. A comparison to the 1980 adaptation, which represented the height of dramatic television in its day, reveals the ways in which our expectations of the form have changed over time. Nevertheless, even the 2024 Shōgun takes its liberties, the most brazen being the use of English instead of Portuguese, the real language of first contact between Japan and the West. Clearly, Portugal has its work cut out: to raise a generation of actors ready to star in the next adaptation by the late twenty-sixties. がんば っ て and boa sorte.

Related content:

16th-Century Japanese Historians Describe the Oddness of Meeting the First Europeans They Ever Saw

The 17th-Century Japanese Samurai Who Sailed to Europe, Met the Pope & Became a Roman Citizen

The History of Ancient Japan: The Story of How Japan Began, Told by Those Who Witnessed It (297‑1274)

Meet Yasuke, Japan’s First Black Samurai Warrior

Let’s Learn Japanese: Two Classic Video Series to Get You Started in the Language

The Entire History of Japan in 9 Quirky Minutes

Based in Seoul, Colin Marshall writes and broadcasts on cities, language, and culture. His projects include the Substack newsletter Books on Cities and the book The Stateless City: a Walk through 21st-Century Los Angeles. Follow him on Twitter at @colinmarshall or on Facebook.

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chrisrosa
23 days ago
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San Francisco, CA
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Trace: New pocket-sized drone for covert aerial surveillance

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So, 2024 is quickly shaping into the year of ultra-capable yet ultra-lightweight nano drones. After HoverAir X1 Pro Max and , drone maker Vantage Robotics has unveiled Trace, a new pocket-sized drone for covert aerial reconnaissance. Trace weighs only 153 grams but carries a multi-camera system and can fly for up to 30 minutes with a single battery.

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chrisrosa
23 days ago
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Launching Model Airplanes With a Custom Linear Induction Motor

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Launching things with electromagnetism is pretty fun, with linear induction motors being a popular design that finds use from everywhere in hobby designs like [Tom Stanton]’s to the electromagnetic launchers on new US and Chinese aircraft carriers. Although the exact design details differ, they use magnetic attraction and repulsion to create a linear motion on the propulsive element, like the sled in [Tom]’s design. Much like the electromagnetic catapults on a Gerald R. Ford-class carrier, electrical power is applied to rapidly move the sled through the channel, akin to a steam piston with a steam catapult.

Model airplane sparking its way through the launcher’s channel. (Credit: Tom Stanton, YouTube)

For [Tom]’s design, permanent magnets are used along both sides of the channel in an alternating north/south pole fashion, with the sled using a single wound coil that uses brushes to contact metal rails along both sides of the channel. Alternating current is then applied to this system, causing the coil to become an electromagnet and propel itself along the channel.

An important consideration here is the number of turns of wire on the sled’s coil, as this controls the current being passed, which is around 90 A for 100 turns. Even so, the fastest sled design only reached a speed of 44 mph (~71 km/h), which is 4 mph faster than [Tom]’s previous design that used coils alongside the channels and a sled featuring a permanent magnet.

One way to increase the speed is to use more coils on the sled, with a two-coil model launching a light-weight model airplane to 10.2 m/s, which is not only a pretty cool way to launch an airplane, but also gives you a sense of appreciation for the engineering challenges involved in making an electromagnetic catapult system work for life-sized airplanes as they’re yeeted off an aircraft carrier and preferably not straight into the drink.

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chrisrosa
35 days ago
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The Secret Inside One Million Checkboxes

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Last year Nolen Royalty made a website called One Million Checkboxes, which presented to the user exactly what it claimed on the tin. The gimmick was that the million checkboxes were shared globally. If I toggled checkbox 206,028 in my browser, you’d see checkbox 206,028 flip state in your browser. Totally pointless. Totally fun.

Here, Royalty tells the story of how the site was used by bot-writing teenage hackers:

Lots of people were mad about bots on OMCB. I’m not going to link to anything here — I don’t want to direct negative attention at anyone — but I got hundreds of messages about bots. The most popular tweet about OMCB complained about bots. People … did not like bots.

And I get it! The typical ways that folks — especially folks who don’t program — bump into bots are things like ticket scalping and restaurant reservation bots. Bots that feel selfish and unfair and antisocial.

And there certainly was botting that you could call antisocial. Folks wrote tiny javascript boxes to uncheck every box that they could — I know this because they excitedly told me. [...]

What this discord did was so cool — so surprising — so creative. It reminded me of me — except they were 10 times the developer I was then (and frankly, better developers than I am now). Getting to watch it live — getting to provide some encouragement, to see what they were doing and respond with praise and pride instead of anger — was deeply meaningful to me. I still tear up when I think about it.

Via Jason Kottke, who aptly observes that the way the hackers got in touch with Royalty “reminds me of the palimpsest (layered communication) that the aliens use to communicate with Earth in Carl Sagan’s Contact (and the 1997 movie).”

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chrisrosa
36 days ago
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really interesting.
San Francisco, CA
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