<TABLE> <S> <C>

<PAGE>
<ARTICLE> 5
<RESTATED> 
<MULTIPLIER> 1,000
       
<S>                             <C>                     <C>                     <C>                     <C>
<C>
<PERIOD-TYPE>                   3-MOS                   3-MOS                   3-MOS                   YEAR
YEAR
<FISCAL-YEAR-END>                          DEC-31-1996             DEC-31-1996             DEC-31-1996             DEC-31-1996
             DEC-31-1995
<PERIOD-START>                             JAN-01-1996             APR-01-1996             JUL-01-1996             JAN-01-1996
             JAN-01-1995
<PERIOD-END>                               MAR-31-1996             JUN-30-1996             SEP-30-1996             DEC-31-1996
             DEC-31-1995
<CASH>                                          21,867                  28,185                  40,508                  47,771
                  30,361
<SECURITIES>                                   138,757                 124,125                 117,509                 119,638
                 130,995
<RECEIVABLES>                                   34,340                  45,501                  48,891                  40,996
                  24,530
<ALLOWANCES>                                       859                   1,137                   1,224                   1,151
                     613
<INVENTORY>                                     31,665                  34,994                  35,708                  35,524
                  27,387
<CURRENT-ASSETS>                               235,131                 241,930                 252,962                 252,065
                 220,875
<PP&E>                                          23,948                  26,975                  27,527                  28,802
                  21,231
<DEPRECIATION>                                   5,904                   7,077                   8,330                   9,560
                   4,879
<TOTAL-ASSETS>                                 261,486                 271,093                 281,795                 280,772
                 245,428
<CURRENT-LIABILITIES>                           51,724                  50,914                  51,175                  39,381
                  44,701
<BONDS>                                              0                       0                       0                       0
                       0
<PREFERRED-MANDATORY>                                0                       0                       0                       0
                       0
<PREFERRED>                                          0                       0                       0                       0
                       0
<COMMON>                                            20                      20                      20                      20
                      20
<OTHER-SE>                                     208,818                 219,310                 229,723                 239,927
                 199,638
<TOTAL-LIABILITY-AND-EQUITY>                   261,486                 271,093                 281,795                 280,772
                 245,428
<SALES>                                         49,568                  49,639                  44,462                 185,058
                 151,124
<TOTAL-REVENUES>                                51,713                  51,793                  46,502                 193,508
                 157,831
<CGS>                                           22,552                  22,297                  19,463                  82,425
                  70,668
<TOTAL-COSTS>                                   24,059                  23,691                  21,159                  88,615
                  75,543
<OTHER-EXPENSES>                                 7,393                   7,307                   6,421                  27,220
                  22,655
<LOSS-PROVISION>                                   247                     278                      87                   1,225
                     371
<INTEREST-EXPENSE>                                  64                      67                      61                     236
                     206
<INCOME-PRETAX>                                 13,093                  14,054                  13,082                  52,707
                  36,170
<INCOME-TAX>                                     4,452                   4,778                   4,247                  17,396
                  11,936
<INCOME-CONTINUING>                              8,641                   9,276                   8,835                  35,311
                  24,234
<DISCONTINUED>                                       0                       0                       0                       0
                       0
<EXTRAORDINARY>                                      0                       0                       0                       0
                       0
<CHANGES>                                            0                       0                       0                       0
                       0
<NET-INCOME>                                     8,641                   9,276                   8,835                  35,311
                  24,234
<EPS-PRIMARY>                                     0.43                    0.46                    0.44                    1.76
                    1.32
<EPS-DILUTED>                                     0.41                    0.44                    0.42                    1.66
                    1.20
        

</TABLE>