<TABLE> <S> <C>

<PAGE>
<ARTICLE> 5
<LEGEND>
THIS SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM THE
CONSOLIDATED INCOME STATEMENT, THE CONSOLIDATED BALANCE SHEETS AND THE
ACCOMPANYING NOTES TO THE CONSOLIDATED FINANCIAL STATEMENTS AND IS QUALIFIED IN
ITS ENTIRETY BY REFERENCE TO SUCH FINANCIAL STATEMENTS.
</LEGEND>
<RESTATED>
<MULTIPLIER> 1,000

<S>                             <C>                     <C>                     <C>                     <C>
<C>
<PERIOD-TYPE>                   YEAR                   3-MOS                   3-MOS                   3-MOS
YEAR
<FISCAL-YEAR-END>                          DEC-31-1996             DEC-31-1996             DEC-31-1996             DEC-31-1996
             DEC-31-1995
<PERIOD-START>                             JAN-01-1996             JAN-01-1996             APR-01-1996             JUN-01-1996
             JAN-01-1995
<PERIOD-END>                               DEC-31-1996             MAR-31-1996             JUN-30-1996             SEP-30-1996
             DEC-31-1995
<CASH>                                          11,176                   7,894                   2,859                   7,534
                  21,438
<SECURITIES>                                    12,243                  15,490                  16,577                  11,841
                       0
<RECEIVABLES>                                   12,038                   5,708                  10,855                  11,950
                   5,423
<ALLOWANCES>                                       950                     200                     300                     350
                     150
<INVENTORY>                                      1,799                   2,186                   1,887                   1,637
                   2,255
<CURRENT-ASSETS>                                37,525                  31,605                  32,717                  33,232
                  29,499
<PP&E>                                           8,855                   5,729                   5,948                   6,429
                   5,922
<DEPRECIATION>                                   4,998                   3,905                   3,937                   4,123
                   4,157
<TOTAL-ASSETS>                                  41,382                  33,429                  34,728                  35,538
                  31,264
<CURRENT-LIABILITIES>                           12,852                   8,408                   8,716                   8,322
                   9,746
<BONDS>                                              0                       0                       0                       0
                       0
<PREFERRED-MANDATORY>                                0                       0                       0                       0
                       0
<PREFERRED>                                          0                       0                       0                       0
                       0
<COMMON>                                             9                       7                       7                       7
                       8
<OTHER-SE>                                      28,521                  24,506                  25,569                  26,814
                  20,909
<TOTAL-LIABILITY-AND-EQUITY>                    41,382                  33,429                  34,728                  35,538
                  31,264
<SALES>                                         35,503                   6,381                   8,721                  10,067
                  18,086
<TOTAL-REVENUES>                                44,109                   7,568                  11,024                  12,369
                  23,464
<CGS>                                           20,262                   3,425                   5,290                   5,563
                   9,306
<TOTAL-COSTS>                                   20,262                   3,425                   5,290                   5,563
                   9,306
<OTHER-EXPENSES>                                     0                       0                       0                       0
                       0
<LOSS-PROVISION>                                     0                       0                       0                       0
                       0
<INTEREST-EXPENSE>                                 146                      29                      44                      46
                     320
<INCOME-PRETAX>                                  3,028                     744                   1,162                   1,268
                   1,347
<INCOME-TAX>                                       665                      83                     149                     136
                     399
<INCOME-CONTINUING>                              2,363                     661                   1,013                   1,132
                     948
<DISCONTINUED>                                       0                       0                       0                       0
                       0
<EXTRAORDINARY>                                      0                       0                       0                       0
                       0
<CHANGES>                                            0                       0                       0                       0
                       0
<NET-INCOME>                                     2,363                     661                   1,013                   1,132
                     948
<EPS-PRIMARY>                                      .27                     .08                     .12                     .13
                     .40
<EPS-DILUTED>                                      .22                     .06                     .10                     .10
                     .11


</TABLE>