<ARTICLE> 5 <MULTIPLIER> 1,000 <PERIOD-TYPE> 6-MOS <FISCAL-YEAR-END> DEC-31-1999 <PERIOD-START> JAN-01-1999 <PERIOD-END> JUN-30-1999 <CASH> 224,208 <SECURITIES> 137,034 <RECEIVABLES> 44,324 <ALLOWANCES> 1,557 <INVENTORY> 14,444 <CURRENT-ASSETS> 291,077 <PP&E> 273,969 <DEPRECIATION> 109,047 <TOTAL-ASSETS> 680,138 <CURRENT-LIABILITIES> 45,082 <BONDS> 0 <PREFERRED-MANDATORY> 0 <PREFERRED> 0 <COMMON> 10,688 <OTHER-SE> 267,914 <TOTAL-LIABILITY-AND-EQUITY> 680,138 <SALES> 130,794 <TOTAL-REVENUES> 133,079 <CGS> 78,724 <TOTAL-COSTS> 78,724 <OTHER-EXPENSES> 32,248 <LOSS-PROVISION> 524 <INTEREST-EXPENSE> 2,256 <INCOME-PRETAX> 19,327 <INCOME-TAX> 6,497 <INCOME-CONTINUING> 12,830 <DISCONTINUED> 0 <EXTRAORDINARY> 0 <CHANGES> 0 <NET-INCOME> 12,830 <EPS-BASIC> 1.50 <EPS-DILUTED> 1.50