<TABLE> <S> <C>

<PAGE>
<ARTICLE> 5
<RESTATED> 
       
<S>                             <C>                     <C>                     <C>
<PERIOD-TYPE>                   9-MOS                   6-MOS                   3-MOS
<FISCAL-YEAR-END>                          APR-30-1997             APR-30-1997             APR-30-1997
<PERIOD-END>                               JAN-31-1997             OCT-31-1996             JUL-31-1996
<CASH>                                       1,776,674               2,381,066               1,565,094
<SECURITIES>                                         0                       0                       0
<RECEIVABLES>                               11,502,069              10,178,335               9,499,511
<ALLOWANCES>                                   284,423                 290,986                 168,639
<INVENTORY>                                 14,839,773              14,852,967              13,676,542
<CURRENT-ASSETS>                            30,468,622              28,663,044              27,294,851
<PP&E>                                      14,638,138              14,281,834              14,350,488
<DEPRECIATION>                               7,600,527               7,800,069               7,314,782
<TOTAL-ASSETS>                              47,029,747              46,064,410              44,176,491
<CURRENT-LIABILITIES>                       10,271,445               9,551,215               9,787,289
<BONDS>                                              0                       0                       0
<PREFERRED-MANDATORY>                                0                       0                       0
<PREFERRED>                                  5,650,000               5,650,000               5,650,000
<COMMON>                                         5,771                   5,687                   5,687
<OTHER-SE>                                  15,450,777              14,782,023              14,120,565
<TOTAL-LIABILITY-AND-EQUITY>                47,029,747              46,064,410              44,176,591
<SALES>                                     42,957,912              28,193,494              14,179,291
<TOTAL-REVENUES>                            44,854,155              29,795,401              15,148,632
<CGS>                                       26,927,385              17,744,681               9,109,120
<TOTAL-COSTS>                               41,483,861              27,631,468              14,055,786
<OTHER-EXPENSES>                                     0                       0                       0
<LOSS-PROVISION>                                     0                       0                       0
<INTEREST-EXPENSE>                             820,059                 526,985                 224,179
<INCOME-PRETAX>                              2,550,235               1,636,948                 868,667
<INCOME-TAX>                                   255,024                 181,000                 117,833
<INCOME-CONTINUING>                          2,120,470               1,352,588                 712,414
<DISCONTINUED>                                       0                       0                       0
<EXTRAORDINARY>                                      0                       0                       0
<CHANGES>                                            0                       0                       0
<NET-INCOME>                                 1,685,376               1,062,527                 567,382
<EPS-PRIMARY>                                     0.30                    0.19                    0.10
<EPS-DILUTED>                                     0.28                    0.17                    0.09
        

</TABLE>