Australia's peak science body has earned a $200 million windfall - and counting - from its long-running patent battles with the world's biggest computer companies.

The CSIRO yesterday delivered its best results in five years, recording a surplus of $122 million in the 2009 financial year - more than twice the size of last year's. It had been budgeting for a $34.2 million loss.

Despite the economic downturn, the CSIRO earned $634.8 million in royalties from its own inventions - the largest amount it has ever recorded and a 74 per cent increase on just two years ago.

Much of this success relates to a patent granted to it in 1996 that the CSIRO argues is essential for setting up wireless networks. It claims the technology is used in more than 800 million devices right now.

The CSIRO has spent years in court seeking royalties from any companies that incorporate the 802.11 wireless standard into their computers, laptops, routers and other products.