<ARTICLE> 5
<MULTIPLIER> 1,000
<CURRENCY> U. S. DOLLARS
       
                             
<PERIOD-TYPE>                   3-MOS
<FISCAL-YEAR-END>                          DEC-31-1998
<PERIOD-START>                             JAN-01-1998
<PERIOD-END>                               MAR-31-1998
<EXCHANGE-RATE>                                      1
<CASH>                                          51,099
<SECURITIES>                                    26,870
<RECEIVABLES>                                   30,603
<ALLOWANCES>                                       786
<INVENTORY>                                     11,953
<CURRENT-ASSETS>                               134,694
<PP&E>                                          31,766
<DEPRECIATION>                                  21,852
<TOTAL-ASSETS>                                 154,119
<CURRENT-LIABILITIES>                           30,397
<BONDS>                                              0
<PREFERRED-MANDATORY>                                0
<PREFERRED>                                          0
<COMMON>                                        82,395
<OTHER-SE>                                      38,603
<TOTAL-LIABILITY-AND-EQUITY>                   154,119
<SALES>                                         34,908
<TOTAL-REVENUES>                                34,908
<CGS>                                           11,405
<TOTAL-COSTS>                                   11,405
<OTHER-EXPENSES>                                13,538
<LOSS-PROVISION>                                     0
<INTEREST-EXPENSE>                                   0
<INCOME-PRETAX>                                 10,735
<INCOME-TAX>                                     4,079
<INCOME-CONTINUING>                              6,656
<DISCONTINUED>                                       0
<EXTRAORDINARY>                                      0
<CHANGES>                                            0
<NET-INCOME>                                     6,656
<EPS-PRIMARY>                                     0.25<F1>
<EPS-DILUTED>                                     0.23
<FN>
<F1>Data listed for "EPS-PRIMARY" is the newly defined "BASIC EPS".
</FN>