<TABLE> <S> <C>

<PAGE>
<ARTICLE> 5
<RESTATED> 
<MULTIPLIER> 1,000
       
<S>                             <C>                     <C>                     <C>
<PERIOD-TYPE>                   12-MOS                   12-MOS                   12-MOS
<FISCAL-YEAR-END>                          DEC-31-1997             DEC-31-1996             DEC-31-1995
<PERIOD-START>                             JAN-01-1997             JAN-01-1996             JAN-01-1995
<PERIOD-END>                               DEC-31-1997             DEC-31-1996             DEC-31-1995
<CASH>                                           4,189                   1,703                   3,722
<SECURITIES>                                        98                     100                     224
<RECEIVABLES>                                    3,291                  13,425                  12,419
<ALLOWANCES>                                       528                   1,337                     296
<INVENTORY>                                        735                   2,664                   1,788
<CURRENT-ASSETS>                                 8,309                  17,511                  18,622
<PP&E>                                           2,660                   5,101                   5,598
<DEPRECIATION>                                       0                       0                       0
<TOTAL-ASSETS>                                  11,256                  29,527                  28,980
<CURRENT-LIABILITIES>                            8,356                  18,751                  11,881
<BONDS>                                              0                       0                       0
<PREFERRED-MANDATORY>                                0                       0                       0
<PREFERRED>                                      4,594                       0                       0
<COMMON>                                         3,622                   2,323                   1,975
<OTHER-SE>                                      72,642                  55,784                  47,837
<TOTAL-LIABILITY-AND-EQUITY>                    11,256                  29,527                  28,980
<SALES>                                          5,385                  18,232                  28,422
<TOTAL-REVENUES>                                15,792                  33,577                  51,117
<CGS>                                            6,421                   8,439                   6,407
<TOTAL-COSTS>                                   10,903                  17,008                  17,493
<OTHER-EXPENSES>                                21,604                  35,004                  31,074
<LOSS-PROVISION>                                     0                       0                       0
<INTEREST-EXPENSE>                               1,360                   3,184                     343
<INCOME-PRETAX>                               (15,076)                (21,376)                   1,957
<INCOME-TAX>                                         0                       0                       0
<INCOME-CONTINUING>                           (15,076)                (21,376)                   1,957
<DISCONTINUED>                                       0                       0                       0
<EXTRAORDINARY>                                      0                       0                       0
<CHANGES>                                            0                       0                       0
<NET-INCOME>                                  (15,076)                (21,376)                 (1,957)
<EPS-PRIMARY>                                   (0.73)                  (1.03)                    0.10
<EPS-DILUTED>                                   (0.73)                  (1.03)                    0.09
        

</TABLE>