How do you deal with 250,000 tapes?

I'm standing in a room with roughly a quarter of a million backup tapes. No, this isn't where the FuelWatch guys hid the evidence, it's the Perth storage area for Spectrum Data, which specialises in storing ageing backup media and helping companies retrieve data from long-forgotten archives.

I'm standing in a room with roughly a quarter of a million backup tapes. No, this isn't where the FuelWatch guys hid the evidence, it's the Perth storage area for Spectrum Data, which specialises in storing ageing backup media and helping companies retrieve data from long-forgotten archives.

In an era where disk costs drop faster than the soaring costs of petrol, it's often easy to forget that there are large volumes of data still sitting on older media. Petrol is a good case in point for why we still need this stuff.

The rising cost of oil potentially makes some of this data more useful than ever for mining companies: oil reserves which once looked uneconomic might now be worth exploiting, and old survey data may well be worth revisiting. But what do you do when that's stored on an ancient backup tape, no-one has the relevant drive anymore and you're not even sure what format the data is in?

Spectrum Data specialises in both long-term storage of archival media and in helping companies pull data off those tapes when the need arises (be that a new need for analysis, an unexpected lawsuit or just a realisation that a bunch of older tapes could be stored more compactly on new media).

Some of this stuff is historic, not just useful. Founder and director Guy Holmes shows me an original NASA tape with data from the Apollo 11 mission, which is suffering from an interesting problem: glue from the label leaking into the centre of the tape reel. (Don't panic; it's a fixable problem and it's not the only copy.)

While we're used to the notion that tape is easily damaged by water, temperature variations and poor handling, other factors come into play, as Holmes explained during my visit.

One that we don't think of much these days is the brand of tape.

While consolidation means there's now only a handful of manufacturers producing magnetic media, and all reach a pretty good level of quality, that wasn't the case in the 1970s and 1980s, Holmes said.

Some manufacturers would sell off inferior batches of tape which would then be rebranded and sold at bargain prices. At the receiving area for tapes at Spectrum, there's a poster detailing dozens of brands and rating them from "excellent" to "poor". Excellent tapes can be read pretty speedily (once they're matched to the right machine); poor tapes may need hand checking and baking (to remove excess moisture) before being read very slowly and under constant supervision.

Even assuming you can read the data, there's no telling what format it might be in. Labels on archive tapes are often deceptive; some businesses would print up labels in advance and use them even if the contents turned out to be different. It's enough to make your reels spin.