<TABLE> <S> <C>

<PAGE>
<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-START>                             JAN-01-1997             JAN-01-1997             JAN-01-1997
<PERIOD-END>                               MAR-31-1997             JUN-30-1997             SEP-30-1997
<CASH>                                            7626                    7571                    6127
<SECURITIES>                                      5933                    5966                    8704
<RECEIVABLES>                                     8863                    9799                   10032
<ALLOWANCES>                                         0                       0                       0
<INVENTORY>                                       3322                    3504                    3414
<CURRENT-ASSETS>                                 26783                   27776                   29066
<PP&E>                                            2704                    2873                    2885
<DEPRECIATION>                                       0                       0                       0
<TOTAL-ASSETS>                                   30222                   31438                   32749
<CURRENT-LIABILITIES>                             7876                    7986                    8358
<BONDS>                                              5                       0                       0
<PREFERRED-MANDATORY>                                0                       0                       0
<PREFERRED>                                          0                       0                       0
<COMMON>                                         26070                   26259                   26321
<OTHER-SE>                                      (3729)                  (2807)                  (1930)
<TOTAL-LIABILITY-AND-EQUITY>                     30222                   31438                   32749
<SALES>                                           8902                   10009                   10758
<TOTAL-REVENUES>                                  8902                   10009                   10758
<CGS>                                             2456                    2698                    2861
<TOTAL-COSTS>                                     6545                    6713                    6880
<OTHER-EXPENSES>                                 (164)                   (167)                   (178)
<LOSS-PROVISION>                                     0                       0                       0
<INTEREST-EXPENSE>                                   4                       4                       3
<INCOME-PRETAX>                                     61                     761                    1192
<INCOME-TAX>                                        19                     114                     180
<INCOME-CONTINUING>                                 42                     647                    1012
<DISCONTINUED>                                       0                       0                       0
<EXTRAORDINARY>                                      0                       0                       0
<CHANGES>                                            0                       0                       0
<NET-INCOME>                                        42                     647                    1012
<EPS-PRIMARY>                                      .01<F1>                 .10<F1>                 .15<F1>
<EPS-DILUTED>                                      .01<F1>                 .09<F1>                 .14<F1>
<FN>
<F1>The adoption in fourth quarter 1997 of FAS 128, a new standard of computing
and presenting both basic and diluted net income per share.
</FN>


</TABLE>