<TABLE> <S> <C>

<PAGE>
<ARTICLE> 5
<LEGEND>
THIS SCHEDULE CONTAINS SUMMARY FINACIAL INFORMATION EXTRACTED FROM THE RESTATED
JUNE 30, 1997, DECEMBER 31, 1997, AND SEPTEMBER 30, 1997 FINANCIAL STATEMENTS
AND IS QUALIFIED IN ITS ENTIRETY BY REFERENCE TO SUCH FINANCIAL STATEMENTS.
</LEGEND>
<RESTATED> 
       
<S>                             <C>                     <C>                     <C>
<PERIOD-TYPE>                   3-MOS                   9-MOS                   6-MOS
<FISCAL-YEAR-END>                          MAR-31-1998             MAR-31-1998             MAR-31-1998
<PERIOD-START>                             APR-01-1997             APR-01-1997             APR-01-1997
<PERIOD-END>                               JUN-30-1997             DEC-31-1997             SEP-30-1997
<CASH>                                         475,471                 416,942               1,406,511
<SECURITIES>                                 4,986,064               3,496,647               3,493,220
<RECEIVABLES>                                  372,308                  75,070                  14,187
<ALLOWANCES>                                         0                       0                       0
<INVENTORY>                                     42,403                  38,637                  69,572
<CURRENT-ASSETS>                             6,097,807               4,134,918               5,144,871
<PP&E>                                         685,422                 289,003                 285,141
<DEPRECIATION>                               (508,028)               (210,010)               (201,954)
<TOTAL-ASSETS>                               6,275,201               4,340,664               5,352,869
<CURRENT-LIABILITIES>                          745,753                 489,960                 761,769
<BONDS>                                         11,813                  23,593                  24,666
<PREFERRED-MANDATORY>                                0                       0                       0
<PREFERRED>                                  1,250,038               1,040,188               1,102,988
<COMMON>                                       163,846                 206,422                 194,654
<OTHER-SE>                                   4,103,751               2,580,501               3,268,792
<TOTAL-LIABILITY-AND-EQUITY>                 6,275,201               4,340,664               5,232,869
<SALES>                                            700                  69,510                     700
<TOTAL-REVENUES>                               101,283                 294,671                 166,546
<CGS>                                           14,002                 122,762                  35,321
<TOTAL-COSTS>                                        0                       0                       0
<OTHER-EXPENSES>                             1,002,730               3,443,733               2,396,875
<LOSS-PROVISION>                                     0                       0                       0
<INTEREST-EXPENSE>                                   0                       0                       0
<INCOME-PRETAX>                              (935,449)             (3,149,057)             (2,265,650)
<INCOME-TAX>                                         0                       0                       0
<INCOME-CONTINUING>                          (935,449)             (3,149,057)             (2,265,650)
<DISCONTINUED>                                       0                       0                       0
<EXTRAORDINARY>                                      0                       0                       0
<CHANGES>                                    1,815,050<F1>           4,360,128<F1>           3,427,958<F1>
<NET-INCOME>                               (2,750,499)             (7,509,185)             (5,693,608)
<EPS-PRIMARY>                                   (0.34)                  (0.84)                  (0.68)
<EPS-DILUTED>                                   (0.34)                  (0.84)                  (0.68)
<FN>
<F1>INCLUDES CONVERTIBLE PREFERRED STOCK DIVIDENDS.
</FN>
        

</TABLE>