<TABLE> <S> <C>


        <S> <C>
<PAGE>

<ARTICLE> 5
<LEGEND>
THIS SCHEDULE CONTAINS RESTATED SUMMARY FINANCIAL INFORMATION EXTRACTED FROM 
FORM 10-Q FOR THE PERIODS ENDED SEPTEMBER 30, JUNE 30, AND MARCH 31, 1997 AND 
IS QUALIFIED IN ITS ENTIRETY BY REFERENCE TO SUCH FINANCIAL STATEMENTS TO 
RETROACTIVELY RESTATE EARNINGS PER SHARE IN ACCORDANCE WITH THE FINANCIAL 
ACCOUNTING STANDARDS BOARD STATEMENT OF FINANCIAL ACCOUNTING STANDARDS NO. 
128, "EARNINGS PER SHARE" ("SFAS 128").
</LEGEND>
<RESTATED>
<MULTIPLIER>    1,000

<S>                       <C>              <C>              <C>
<PERIOD-TYPE>              9-MOS            6-MOS            3-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>               SEP-30-1997      JUN-30-1997      MAR-31-1997 
<CASH>                          10,881           12,077           13,378  
<SECURITIES>                     5,979 <F1>       6,669 <F1>       7,023 <F1> 
<RECEIVABLES>                       81               37               48 
<ALLOWANCES>                         0                0                0 
<INVENTORY>                        100               58               83 
<CURRENT-ASSETS>                14,205           17,435           19,954 
<PP&E>                           1,197 <F2>       1,230 <F2>       1,220 <F2>
<DEPRECIATION>                       0                0                0 
<TOTAL-ASSETS>                  18,503           20,271           22,778 
<CURRENT-LIABILITIES>            1,048              941              958 
<BONDS>                              0                0                0 
<PREFERRED-MANDATORY>                0                0                0 
<PREFERRED>                          0                0                0 
<COMMON>                         7,066            7,063            7,025 
<OTHER-SE>                      17,392           20,264           21,757 
<TOTAL-LIABILITY-AND-EQUITY>    18,503           20,271           22,778 
<SALES>                            144               78                0 
<TOTAL-REVENUES>                   144               78               50 
<CGS>                              576              382              158 
<TOTAL-COSTS>                      576              382              158 
<OTHER-EXPENSES>                 4,024 <F3>       2,583 <F3>       1,241 <F3>
<LOSS-PROVISION>                     0                0                0 
<INTEREST-EXPENSE>                  11                0                5 
<INCOME-PRETAX>                (6,973)          (4,574)          (2,090) 
<INCOME-TAX>                         0                0                0 
<INCOME-CONTINUING>            (6,973)          (4,574)          (2,090) 
<DISCONTINUED>                       0                0                0 
<EXTRAORDINARY>                      0                0                0 
<CHANGES>                            0                0                0 
<NET-INCOME>                   (6,973)          (4,574)          (2,090) 
<EPS-PRIMARY>                   (0.99) <F4>      (0.65) <F4>      (0.30) <F4>
<EPS-DILUTED>                   (0.99)           (0.65)           (0.30)

<FN>

<PAGE>


<F1> Securities, item 5-02(2) are net of accrued interest and unrealized
     gain/loss.
<F2> Item shown net of allowance, consistent with the balance sheet
     presentation.
<F3> Item consists of research and development.
<F4> Item consists of basic earnings per share.
</FN>

        

</TABLE>