<TABLE> <S> <C>

<PAGE>
<ARTICLE> 5
<RESTATED> 
       
<S>                             <C>                     <C>                     <C>                     <C>
<PERIOD-TYPE>                   12-MOS                   12-MOS                   3-MOS                   6-MOS
<FISCAL-YEAR-END>                          JUL-31-1997             JUL-31-1996             JUL-31-1998             JUL-31-1998
<PERIOD-START>                             AUG-01-1996             AUG-01-1995             AUG-01-1997             AUG-01-1997
<PERIOD-END>                               JUL-31-1997             JUL-31-1996             OCT-31-1998             JAN-01-1998
<CASH>                                         155,826                  65,267                 108,834                  73,734
<SECURITIES>                                         0                       0                       0                       0
<RECEIVABLES>                                2,969,852               2,239,315               3,448,308               4,320,393
<ALLOWANCES>                                   147,714                 198,675                 149,403                 127,584
<INVENTORY>                                  3,465,316               2,497,298               3,655,130               3,612,201
<CURRENT-ASSETS>                             7,857,496               5,297,378               8,081,576               8,439,054
<PP&E>                                       3,216,450               2,510,229               3,268,961               3,287,988
<DEPRECIATION>                               1,739,049               1,386,962               1,858,298               1,966,383
<TOTAL-ASSETS>                              17,604,726              10,131,990              17,710,513              17,892,663
<CURRENT-LIABILITIES>                        7,153,320               2,711,403               6,392,009               6,311,077
<BONDS>                                              0                       0                       0                       0
<PREFERRED-MANDATORY>                                0                       0                       0                       0
<PREFERRED>                                          0                       0                       0                       0
<COMMON>                                        25,472                  25,472                  25,472                  25,472
<OTHER-SE>                                   5,899,229               5,299,953               6,197,515               6,718,699
<TOTAL-LIABILITY-AND-EQUITY>                17,604,726              10,131,990              17,710,513              17,892,663
<SALES>                                     14,123,243              12,385,777               5,345,640              10,812,174
<TOTAL-REVENUES>                            14,123,243              12,385,777               5,345,640              10,812,174
<CGS>                                        8,155,751               6,766,875               3,001,686               6,218,703
<TOTAL-COSTS>                                8,155,751               6,766,875               3,001,686               6,218,703
<OTHER-EXPENSES>                             4,811,263               4,506,008               1,675,673               3,302,230
<LOSS-PROVISION>                                     0                       0                       0                       0
<INTEREST-EXPENSE>                             321,307                 140,764                 294,082                 559,788
<INCOME-PRETAX>                                850,276               1,015,962                 377,287                 716,471
<INCOME-TAX>                                   351,000                 349,416                 139,000                 282,000
<INCOME-CONTINUING>                                  0                       0                       0                       0
<DISCONTINUED>                                       0                       0                       0                       0
<EXTRAORDINARY>                                      0                       0                       0                       0
<CHANGES>                                            0                       0                       0                       0
<NET-INCOME>                                   499,276                 666,546                 238,287                 434,471
<EPS-PRIMARY>                                      .20                     .26                     .09                     .17
<EPS-DILUTED>                                      .19                     .25                     .09                     .16
        

</TABLE>