<TABLE> <S> <C>

<PAGE>
<ARTICLE> 5
<RESTATED>

<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>                                             702                   1,175                   2,619
<SECURITIES>                                     5,336                   5,386                   4,134
<RECEIVABLES>                                   14,231                  12,324                  12,322
<ALLOWANCES>                                       676                     425                     313
<INVENTORY>                                      4,129                   2,715                   3,480
<CURRENT-ASSETS>                                27,224                  25,183                  26,144
<PP&E>                                          19,423                  22,426                  24,363
<DEPRECIATION>                                   7,482                   8,461                   9,603
<TOTAL-ASSETS>                                  48,024                  49,920                  52,031
<CURRENT-LIABILITIES>                           12,879                  13,000                  13,875
<BONDS>                                          3,213                   6,422                   6,194
<PREFERRED-MANDATORY>                                0                       0                       0
<PREFERRED>                                          0                       0                       0
<COMMON>                                            80                      80                      81
<OTHER-SE>                                      29,344                  30,418                  30,754
<TOTAL-LIABILITY-AND-EQUITY>                    48,024                  49,920                  52,031
<SALES>                                          7,441                  13,984                  19,216
<TOTAL-REVENUES>                                17,661                  32,805                  47,224
<CGS>                                            5,488                   9,414                  12,745
<TOTAL-COSTS>                                   12,350                  22,028                  32,059
<OTHER-EXPENSES>                                 3,761                   7,746                  11,630
<LOSS-PROVISION>                                   676                      31                    (21)
<INTEREST-EXPENSE>                                   0                       0                       0
<INCOME-PRETAX>                                  1,509                   2,974                   3,486
<INCOME-TAX>                                       549                   1,081                   1,261
<INCOME-CONTINUING>                              1,550                   1,893                   2,225
<DISCONTINUED>                                       0                       0                       0
<EXTRAORDINARY>                                      0                       0                       0
<CHANGES>                                            0                       0                       0
<NET-INCOME>                                       960                   1,893                   2,225
<EPS-PRIMARY>                                      .12                     .12                     .04
<EPS-DILUTED>                                      .12                     .11                     .04


</TABLE>