<ARTICLE>                     5
<MULTIPLIER>                                   1000

                             
<PERIOD-TYPE>                   3-MOS
<FISCAL-YEAR-END>                              Dec-31-1999
<PERIOD-END>                                   Mar-31-2000
<CASH>                                          84,913
<SECURITIES>                                    41,755
<RECEIVABLES>                                   76,166
<ALLOWANCES>                                         0
<INVENTORY>                                      2,605
<CURRENT-ASSETS>                               214,580
<PP&E>                                         131,961
<DEPRECIATION>                                 (92,462)
<TOTAL-ASSETS>                                 263,441
<CURRENT-LIABILITIES>                           87,001
<BONDS>                                              0
<PREFERRED-MANDATORY>                                0
<PREFERRED>                                          0
<COMMON>                                       149,873
<OTHER-SE>                                      20,012
<TOTAL-LIABILITY-AND-EQUITY>                   263,441
<SALES>                                         53,320
<TOTAL-REVENUES>                                92,802
<CGS>                                            7,180
<TOTAL-COSTS>                                   30,285
<OTHER-EXPENSES>                                55,084
<LOSS-PROVISION>                                     0
<INTEREST-EXPENSE>                                   0
<INCOME-PRETAX>                                  8,625
<INCOME-TAX>                                     2,156
<INCOME-CONTINUING>                              6,469
<DISCONTINUED>                                       0
<EXTRAORDINARY>                                      0
<CHANGES>                                            0
<NET-INCOME>                                     6,469
<EPS-BASIC>                                        .19
<EPS-DILUTED>                                      .18