<ARTICLE> 5
<MULTIPLIER> 1,000
       
                                                 
<PERIOD-TYPE>                                    6-MOS
<FISCAL-YEAR-END>                          DEC-31-1997
<PERIOD-END>                               JUN-30-1997
<CASH>                                          73,250
<SECURITIES>                                   282,611
<RECEIVABLES>                                   58,495
<ALLOWANCES>                                     1,312
<INVENTORY>                                     23,931
<CURRENT-ASSETS>                               498,222
<PP&E>                                         224,970
<DEPRECIATION>                                  57,681
<TOTAL-ASSETS>                                 704,912
<CURRENT-LIABILITIES>                           81,690
<BONDS>                                         64,289
<PREFERRED-MANDATORY>                                0
<PREFERRED>                                          0
<COMMON>                                           739
<OTHER-SE>                                     558,194
<TOTAL-LIABILITY-AND-EQUITY>                   704,912
<SALES>                                        109,056
<TOTAL-REVENUES>                               197,391
<CGS>                                           23,188
<TOTAL-COSTS>                                  135,378
<OTHER-EXPENSES>                                   144
<LOSS-PROVISION>                                     0
<INTEREST-EXPENSE>                               2,179
<INCOME-PRETAX>                                 62,013
<INCOME-TAX>                                    25,055
<INCOME-CONTINUING>                             36,958
<DISCONTINUED>                                       0
<EXTRAORDINARY>                                      0
<CHANGES>                                            0
<NET-INCOME>                                    36,958
<EPS-PRIMARY>                                     0.48
<EPS-DILUTED>                                     0.48