George R.R. Martin writes each instalment of his hugely successful Game of Thrones books on a vintage disk operating system (DOS) because he gets frustrated by new technology.

The popular author revealed his writing “secret weapon” of choice during an appearance on Conan: DOS word processing program Word Star 4.0, an ancient operating system popular in the late 70’s and early 80’s.

Martin admitted that he owns two computers: one for emails and taxes and another that he uses purely for writing which is installed with the retro program.

His old computer has no internet for mindless distraction and is at little risk of being hacked or destroyed by a virus.

The eccentric 65-year-old expressed annoyance over modern operating systems, blaming the autocorrect functions for his reliance on old school technology.

“I don’t want any help. I hate some of these modern systems where you type a lower-case letter and it becomes a capital,” he told Conan O’Brien. “I don’t want a capital. If I wanted a capital, I would have typed a capital. I know how to work this ship. Stop fixing it.”

Spell check is not ideal either, especially for a man whose character names are notoriously complex.

“Oh, I hate spell check,” Martin laughed.