<ARTICLE> 5
<MULTIPLIER> 1,000
       
                                                  
<PERIOD-TYPE>                   3-MOS                   6-MOS
<FISCAL-YEAR-END>                          SEP-30-1998             SEP-30-1998
<PERIOD-START>                             JAN-01-1998             OCT-01-1997
<PERIOD-END>                               MAR-31-1998             MAR-31-1998
<CASH>                                          92,243                  92,243
<SECURITIES>                                    52,053                  52,053
<RECEIVABLES>                                   29,984                  29,984
<ALLOWANCES>                                     1,205                   1,205
<INVENTORY>                                     13,490                  13,490
<CURRENT-ASSETS>                               203,639                 203,639
<PP&E>                                          87,447                  87,447
<DEPRECIATION>                                  32,081                  32,081
<TOTAL-ASSETS>                                 318,296                 318,296
<CURRENT-LIABILITIES>                           28,023                  28,023
<BONDS>                                             71                      71
<PREFERRED-MANDATORY>                                0                       0
<PREFERRED>                                          0                       0
<COMMON>                                       280,193                 280,193
<OTHER-SE>                                      10,009                  10,009
<TOTAL-LIABILITY-AND-EQUITY>                   318,296                 318,296
<SALES>                                         40,212                  74,913
<TOTAL-REVENUES>                                40,212                  74,913
<CGS>                                           16,012                  30,206
<TOTAL-COSTS>                                   27,323                  51,334
<OTHER-EXPENSES>                                     0                       0
<LOSS-PROVISION>                                     0                       0
<INTEREST-EXPENSE>                                   8                      18
<INCOME-PRETAX>                                 15,070                  28,043
<INCOME-TAX>                                     3,014                   5,608
<INCOME-CONTINUING>                             12,056                  22,435
<DISCONTINUED>                                       0                       0
<EXTRAORDINARY>                                      0                       0
<CHANGES>                                            0                       0
<NET-INCOME>                                    12,056                  22,435
<EPS-PRIMARY>                                     0.33                    0.62
<EPS-DILUTED>                                     0.31                    0.57