Pressure is growing on Acorn either to relax its copyright policy or to change its locks wholesale.

Acornsoft has launched a service that it promised before Christmas to let owners of cassette-based software trade in programs for disk equivalents at half the normal price. But at the same time another magazines had undermined its locking mechanism, demonstrating how simple a matter it is to sidestep the protection of a software lock.

Software houses selling routines with a similar purpose are also continuing to trade, and an Acorn spokesman said: "Until somebody produces a lock that's uncrackable you'll just have to keep on changing your lock."

Acorn hasn't given up hope of protecting its software through legal channels. Having won an out-of-court settlement against the monthly Personal Computer World before Christmas (issue 42), it says that it may now take on Acorn User for an article the magazine ran in its February issue. "Some action is being considered but I don't know what it is going to be," said the spokesman.

But in this case it may not need to go to law. Redwood Publishing, a company of which non-executive Acorn director Christopher Ward is a director, is in the process of buying the magazine. The Acorn spokesman acknowledged that links exist between the two companies and admitted that the idea of Acornsoft taking legal action against a Redwood title was an unlikely prospect.