(Pocket-lint) - The Game of Thrones author George RR Martin has revealed why he does all his writing work on an old DOS machine.

The disk operating system (DOS) machine isn't used for its olde feel, nay it's the lack of spell checking Martin likes. He also told Conan O'Brien on his show that he felt safe it would never get infected with a virus. He uses a second computer for browsing the internet.

Martin said: "I actually like it, it does what I want a word-processing programme to do and it doesn't do anything else. I don't want any help, you know? I hate some of these modern systems where you type a lower case letter and it becomes a capital. I don't want a capital. If I'd wanted a capital, I'd have typed a capital. I know how to work the shift key. Stop fixing it."

With names like Targaryen and Ygritte, it's not hard to see why he's a fan of spell-check-free computing. He uses WordStar 4.0 as the DOS word-processing program of choice. Just like the scholars did it back in the days of fire and stone. Oh, wait.

Martin calls his machine the "Duesenberg of word-processing software (very old, but unsurpassed)", referring to the long-since dead American car manufacturer.

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Writing by Luke Edwards.