<TABLE> <S> <C>


<ARTICLE> 5
<RESTATED> 
<MULTIPLIER> 1,000
       
<S>                             <C>                     <C>                     <C>
<PERIOD-TYPE>                   3-MOS                   6-MOS                   9-MOS
<FISCAL-YEAR-END>                          DEC-31-1997             DEC-31-1997             DEC-31-1997
<PERIOD-END>                               MAR-31-1997             JUN-30-1997             SEP-30-1997
<CASH>                                           2,898                   2,898                   5,456
<SECURITIES>                                    18,689                  20,994                  24,541
<RECEIVABLES>                                    4,963                   5,850                   5,288
<ALLOWANCES>                                       125                     125                     125
<INVENTORY>                                      4,524                   4,712                   4,660
<CURRENT-ASSETS>                                32,164                  35,734                  41,166
<PP&E>                                           4,846                   4,985                   5,141
<DEPRECIATION>                                   2,397                   2,608                   2,824
<TOTAL-ASSETS>                                  50,660                  52,313                  54,665
<CURRENT-LIABILITIES>                            2,991                   3,720                   4,123
<BONDS>                                              0                       0                       0
<PREFERRED-MANDATORY>                                0                       0                       0
<PREFERRED>                                          0                       0                       0
<COMMON>                                        36,920                  37,035                  37,496
<OTHER-SE>                                      10,749                  11,657                  13,145
<TOTAL-LIABILITY-AND-EQUITY>                    50,660                  52,313                  54,665
<SALES>                                          7,080                  15,337                  24,586
<TOTAL-REVENUES>                                 7,080                  15,337                  24,586
<CGS>                                            3,374                   7,229                  11,125
<TOTAL-COSTS>                                    3,374                   7,229                  11,125
<OTHER-EXPENSES>                                     0                       0                       0
<LOSS-PROVISION>                                     0                       0                       0
<INTEREST-EXPENSE>                                   0                       0                       0
<INCOME-PRETAX>                                    864                   2,055                   4,242
<INCOME-TAX>                                       275                     657                   1,357
<INCOME-CONTINUING>                                589                   1,398                   2,885
<DISCONTINUED>                                       0                       0                       0
<EXTRAORDINARY>                                      0                       0                       0
<CHANGES>                                            0                       0                       0
<NET-INCOME>                                       589                   1,398                   2,885
<EPS-PRIMARY>                                     0.11                    0.27                    0.55
<EPS-DILUTED>                                     0.11                    0.26                    0.53
        


</TABLE>