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Comment by blinkingled | Hacker News Reader

Is it possible to backup and use the DVD content from local disk? Haven't had the best of luck with DVDs and buying one of eBay makes me feel even less optimistic the DVDs will last long.

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The content is just a whole bunch of JPG files that have been XORed with 239. If you XOR them with 239 again, you get the original JPG images. If you do a Google search, you should be able to find several programs/scripts that will do the job for you.

I bought the DVDs. It used Adobe Air which I had never heard of and is discontinued. Each page of the magazine is in some encrypted format but I found software on the internet to decrypt it. You can use cp to get those files. Then you can google about the encryption.

My parents got me a subscription in 1987 when I was a kid and I'm still a print edition subscriber and linked my online account to my subscription. I can read any issue online as well and print to PDF so I do that every couple of months so I have every issue from 1888 to 2023.

Thanks, not going to bother with the DVDs then. Will check out if subscription is reasonable and go that route.

The Adobe Air program was basically just a front end to display and decrypt everything. I could never get it to work on Linux so I never actually even looked at it except the screenshots in the help document.

All the files are named well like NGM_1918_04_125.jpg

National Geographic Magazine, year 1918, 4th month (April), page 125

Yeah, it was annoying but I ran a for loop on every file in the 80GB or so to translate it to normal JPEG. It took about 24 hours and that was 10 years ago on a much older computer.

Adobe AIR was a precursor to Electron in the late 00s. It allowed apps written in JavaScript, ActionScript and some other Adobe tech to be easily built for multiple platforms.

I remember Disk Utility on macOS being able to dump the raw data from a DVD or CD into a disk image. And I think virtualization software can mount the image as if it was a disc.

It’s been at least 5 years since I’ve done anything like that though.

Edit: You can always use dd to grab the raw data.

Manufactured discs usually last a very long time.

OP might be concerned with not having a CDROM in their machine. Same concern that many of us may have in 20 years.

I have older software on 3.5" floppy disks that I can no longer access, and fortunately have the disk images.

You can get a 3.5" drive with a USB cable. Works well.

Thanks, i'll look into it as a secondary backup.

"Usually"

Not sure I'd trust my only copy of something I want to keep long term to a "usually."

My CDs from 1986 are fine.

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