<ARTICLE> 5
<LEGEND>
THIS SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM THE
QUARTERLY REPORT ON FORM 10Q FOR THE FISCAL QUARTER ENDED DECEMBER 31, 1999 AND
IS QUALIFIED IN ITS ENTIRETY BY REFERENCE TO SUCH FINANCIAL STATEMENTS.
</LEGEND>
<MULTIPLIER> 1,000

                             
<PERIOD-TYPE>                   3-MOS
<FISCAL-YEAR-END>                          MAR-31-2000
<PERIOD-START>                             OCT-01-1999
<PERIOD-END>                               DEC-31-1999
<CASH>                                          22,774
<SECURITIES>                                    92,494
<RECEIVABLES>                                   21,172
<ALLOWANCES>                                       318
<INVENTORY>                                     10,522
<CURRENT-ASSETS>                               155,027
<PP&E>                                          74,198
<DEPRECIATION>                                  40,199
<TOTAL-ASSETS>                                 192,383
<CURRENT-LIABILITIES>                           26,079
<BONDS>                                          5,830
<PREFERRED-MANDATORY>                                0
<PREFERRED>                                          0
<COMMON>                                           541
<OTHER-SE>                                     159,933
<TOTAL-LIABILITY-AND-EQUITY>                   192,383
<SALES>                                         45,762
<TOTAL-REVENUES>                                45,762
<CGS>                                           13,209
<TOTAL-COSTS>                                   13,209
<OTHER-EXPENSES>                                15,342
<LOSS-PROVISION>                                     0
<INTEREST-EXPENSE>                                 150
<INCOME-PRETAX>                                 18,436
<INCOME-TAX>                                     6,324
<INCOME-CONTINUING>                             12,112
<DISCONTINUED>                                       0
<EXTRAORDINARY>                                      0
<CHANGES>                                            0
<NET-INCOME>                                    12,112
<EPS-BASIC>                                       0.23
<EPS-DILUTED>                                     0.21