London — Britain's microcomputer companies are expanding their research efforts in a bid to keep abreast of the competition in this fast-changing technological area. Sinclair Research and Acorn, the best known of the clutch of the United Kingdom microcomputer companies, are putting cash behind research in artificial intelligence to make their products easier to use.
Sinclair is opening a new research center early next year which will concentrate on artificial intelligence. The center, called Metalab, will be housed in a converted country house on the outskirts of Cambridge, which Sinclair is equipping at a cost of $2.9 million.
For Acorn's part, its 100-strong R&D group specializes in chip fabrication and networking (ways of connecting computers), as well as the more obvious work on the design of hardware and software.
Both companies say that within three to five years they will sell machines that respond to the spoken word. The devices should appeal to people who dislike giving instructions to computers with a keyboard.
Meanwhile, another research goal of Sinclair Research is to devise ''intelligent'' home data bases that will give advice on, say, car mechanics or how to make a souffle.
Dreaming up such mechanisms requires a lot of costly and highly skilled research in both the software and hardware elements of computers.
But according to the thinking of Sinclair and Acorn, putting cash in this direction is the one way to avoid the fate of personal computer manufacturers that have dropped out of the business.
The growth of both Sinclair Research and Acorn over the past few years has been spectacular. Sinclair, formed in 1979, clocked up sales of $78.3 million last year, mainly from cheap Timex Sinclair home computers. (It also makes other consumer items such as pocket televisions.)
Acorn, which is a year older, has built its reputation on the strength of its success with a product known as the BBC microcomputer.
Acorn's sales increased almost fivefold this year over last, to $61 million. Acorn recently began selling the BBC micro in the United States.