<TABLE> <S> <C>

<PAGE>
<ARTICLE> 5
<LEGEND>
THIS SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM THE
COMPANY'S FORM 10-K AND FORMS 10-Q FOR FISCAL YEAR 1996. THE FIGURES
HEREIN REFLECT THE FEBRUARY 1997 MERGER OF THE COMPANY WITH SPEEDSIM, INC.
WHICH WAS ACCOUNTED FOR AS A POOLING OF INTERESTS.
</LEGEND>
<RESTATED>
<MULTIPLIER> 1,000

<S>                              <C>                     <C>                     <C>                      <C>
<PERIOD-TYPE>                    YEAR                   3-MOS                   6-MOS                     9-MOS
<FISCAL-YEAR-END>                            DEC-31-1996             DEC-31-1996             DEC-31-1996             DEC-31-1996
<PERIOD-START>                               JAN-01-1996             JAN-01-1996             JAN-01-1996             JAN-01-1996
<PERIOD-END>                                 DEC-31-1996             MAR-31-1996             JUN-30-1996             SEP-30-1996
<CASH>                                            25,790                  21,339                  24,078                  29,425
<SECURITIES>                                      10,614                  15,927                  15,109                  13,678
<RECEIVABLES>                                     23,608                  17,825                  23,221                  21,352
<ALLOWANCES>                                       1,840                   1,840                   1,867                   1,840
<INVENTORY>                                       10,141                   9,284                  10,055                  10,059
<CURRENT-ASSETS>                                  77,175                  70,033                  78,551                  80,241
<PP&E>                                            33,158                  28,331                  30,698                  31,433
<DEPRECIATION>                                    21,915                  15,424                  17,469                  19,419
<TOTAL-ASSETS>                                   111,977                  97,115                 106,398                 107,773
<CURRENT-LIABILITIES>                             27,932                  24,162                  30,352                  27,932
<BONDS>                                                0                       0                       0                       0
<PREFERRED-MANDATORY>                                  0                       0                       0                       0
<PREFERRED>                                            0                       0                       0                       0
<COMMON>                                              17                      16                      16                      16
<OTHER-SE>                                        84,028                  69,799                  73,414                  78,388
<TOTAL-LIABILITY-AND-EQUITY>                     111,977                  97,115                 106,398                 107,773
<SALES>                                          109,578                  23,868                  50,127                  78,914
<TOTAL-REVENUES>                                 109,578                  23,868                  50,127                  78,914
<CGS>                                             32,663                   7,144                  15,057                  23,539
<TOTAL-COSTS>                                     32,663                   7,144                  15,057                  23,539
<OTHER-EXPENSES>                                  58,942                  13,017                  27,419                  42,685
<LOSS-PROVISION>                                       0                       0                       0                       0
<INTEREST-EXPENSE>                                   429                     132                     240                     354
<INCOME-PRETAX>                                   19,852                   4,019                   8,450                  14,022
<INCOME-TAX>                                       5,721                   1,275                   2,716                   4,416
<INCOME-CONTINUING>                               14,131                   2,744                   5,734                   9,606
<DISCONTINUED>                                         0                       0                       0                       0
<EXTRAORDINARY>                                        0                       0                       0                       0
<CHANGES>                                              0                       0                       0                       0
<NET-INCOME>                                      14,131                   2,744                   5,734                   9,606
<EPS-PRIMARY>                                       0.87                    0.17                    0.35                    0.59
<EPS-DILUTED>                                       0.79                    0.16                    0.32                    0.54


</TABLE>