WARNING: THE EDGAR SYSTEM ENCOUNTERED ERROR(S) WHILE PROCESSING THIS SCHEDULE.

  


<ARTICLE>                                                 5
<MULTIPLIER>                                            1000
       
                                                                                                 
<PERIOD-TYPE>                                    12-MOS          12-MOS                    3-MOS           3-MOS
<FISCAL-YEAR-END>                                Dec-31-1995     Dec-31-1996               Dec-31-1997     Dec-31-1998
<PERIOD-END>                                     Dec-31-1995     Dec-31-1996               Mar-31-1997     Mar-31-1998
<CASH>                                                 11962           12574                     10583           12628
<SECURITIES>                                           21856           18238                     17218           71449
<RECEIVABLES>                                          12890<F1>       13804<F1>                 16196<F1>       20164<F1>
<ALLOWANCES>                                               0               0                         0               0
<INVENTORY>                                             3579            6503                      8641            9291
<CURRENT-ASSETS>                                       52343           56036                     57790          117444
<PP&E>                                                 19522<F2>       30660<F2>                 34494<F2>       36810<F2>
<DEPRECIATION>                                             0               0                         0               0
<TOTAL-ASSETS>                                         78590           93191                     99366          160747
<CURRENT-LIABILITIES>                                  18122           19450                     22328           19290
<BONDS>                                                    0               0                         0               0
<PREFERRED-MANDATORY>                                      0               0                         0               0
<PREFERRED>                                                0               0                         0               0
<COMMON>                                                 178             179                       183             202
<OTHER-SE>                                             45118           55473                     58102          122333
<TOTAL-LIABILITY-AND-EQUITY>                           78590           93191                     99366          160747
<SALES>                                                60172           88661                     22513           27376
<TOTAL-REVENUES>                                       60172           88661                     22513           27376
<CGS>                                                  29723           41231                     11487           12346
<TOTAL-COSTS>                                          29723           41231                     11487           12346
<OTHER-EXPENSES>                                        5697<F3>        9838<F3>                 2465<F3>         2788<F3>
<LOSS-PROVISION>                                           0               0                         0               0
<INTEREST-EXPENSE>                                      1320            1635                       376             412
<INCOME-PRETAX>                                         7966           15024                      3417            6748
<INCOME-TAX>                                            2888            3158                       920            2228
<INCOME-CONTINUING>                                        0               0                         0               0
<DISCONTINUED>                                             0               0                         0               0
<EXTRAORDINARY>                                            0               0                         0               0
<CHANGES>                                                  0               0                         0               0
<NET-INCOME>                                            5088           12017                      2516            4465
<EPS-BASIC>                                              .32             .70                       .15             .25
<EPS-ASSUMING DILUTION>                                  .30             .65                       .13             .24


<FN>
<F1>Net of  allowance  for doubtful  accounts,  consistent  with  balance  sheet
presentation.
<F2>Net of accumulated depreciation, consistent with balance sheet
presentation.
<F3>Research and development expenses
</FN>