Monday, March 06, 2017

Bit Rot or How do I read this data?

Last night I had a very weird dream. In it I was trying to recover the programs I wrote in college. I have saved most of them. Well in a manner of speaking. Some of them are on punch cards. Yes, I have 40+ year old punch cards in the attic. I can read them as they have the letters typed along the top. And I could probably figure out the hole punches if it came to that. On the other hand, more of my programs were saved on a DECtape. That was the subject of my dream FWIW.

Image result for dectapeWhat? You don’t know about DECtape? It was a proprietary magnetic tape for storing data. A powerful and reliable tool in its day. These days machines that can read one exist for the most part in museums and the occasional Canadian Nuclear power plant. Since I have access to neither getting the data off of my old tape seems unlikely.

This is a problem most of us do not pay much attention to. We think short term as in now or a few years. And yet time after time we have seen storage types become obsolete leaving access to the information stored on them inaccessible. Even when devices are still available often the media deteriorates. I’ve read a lot about Disc Rot as older CDs and other optical media are starting to stored deteriorate.

This is not a new problem. There are many ancient documents (word used loosely) that are difficult if not impossible to read because the language has been lost. We don’t know how many things were done in ancient times because the information was lost. Just look at all the theories and questions about how the Egyptian pyramids would built for example.

Some people do worry about this. I have heard that Apple, for example, has a vault with older computer hardware stored in case it is some day needed. And smart CIOs have plans to move data to newer data storage devices as they become commonly used.  I suspect though that most regular people don’t give it a second thought. We just assume that all our data will always be there.

If we’re careful maybe it will be. I typically move all the data from an old machine to a new one when I get one. Or I store the important stuff in “the cloud” assuming that someone else is keeping it safe and current. Over the years I have moved data from tapes to disks to CDs to USB drives to the cloud. Have I kept it all? Probably not. Without a good plan losing things is inevitable. Somehow I lost those student written programs of the 1970s. But I like to think I have kept the most important things. I’m thinking though that I need to talk about this with my students. If I don’t make them think about it will they see the problem on their own? Will they see it in time to do things about it?

Now if only I could get to that DECtape and see how bad the code I wrote as a student is.

1 comment:

Mark DeLoura said...

I love this... it's a dream I can certainly relate to :) A few years ago I bought a working NeXT off eBay to try and recover data from an old optical disc. Those drives are notoriously fiddly over time though, and sure enough, I couldn't get one that worked (I even dug up two other drives on eBay and tried those!) Eventually I shipped my disc to someone with a working drive and they sent me back a .tgz with a bunch of my old code. yay!

For DECtape you might scope out Living Computers Museum & Labs and see if they have a working drive you could pull data from. I suspect that they do, and the intent of the museum is to keep these historic machines up and running so that you can fiddle with them. Might be worth a go!