Business Notes COMPUTERS

Five years ago, IBM was forced to retreat from the home-computer business after its PCjr. proved to be a flop. Last week the company rolled out a new line of computers designed for novice users. The PS/1 represents a vast improvement over the PCjr., which was much maligned as awkward and toylike. The new computers come loaded with user-friendly software programs, and IBM has developed an electronic hot line to help first-time buyers. Yet the PS/1 faces obstacles, notably the abundance of competitors. Another drawback is PS/ 1's cost, estimated at $1,000 to $2,000, which may be too high for many households.