International Business Machines Corp. has stopped taking orders on all but three models of its old personal computer line, it confirmed yesterday.

Demand for the old personal computers has exceeded supply since IBM began curtailing their production in connection with its April 2 announcement of its Personal System 2.

The Personal System 2 models are more compact and powerful and provide better graphics and connectivity to other IBM computers. However, older personal computers from IBM and its competitors are in demand from customers who feel the extra features are not worth the price.

IBM is still taking orders on one AT model, the 339, and on a hybrid personal computer, the XT 286, spokesman Cary Ziter said. A standard XT model with a 20-megabyte hard disk is being sold as it is available, Ziter said. He said two other models of the XT on which IBM recently stopped taking orders have not actually been discontinued, raising the possibility that order-taking could resume. The Personal System 2 is selling well, Ziter said.

"Our high-volume bid activity with major customers has been very encouraging. Overseas, the reception is also very encouraging. In short, demand from our direct customers and our dealers is very positive and the company is doing everything it can to deliver new systems to them," Ziter said, reading from a company statement.