NY -- Standard&Poor's CreditWire 11/24/98 – Standard&Poor's today assigned its single-'A' rating to Orange County, Fla.'s $295.3 million tourist development tax revenue bonds series 1998A and B dated Dec. 1, 1998 due Dec. 1, 2022. The bonds are scheduled to sell Dec. 2, 1998. At the same time, Standard&Poor's affirmed its single-'A' underlying rating (SPUR) on the county's $193.49 million tourist development tax refunding bonds series 1997A dated July 15, 1997 due Oct. 1, 1998-2021. The rating reflects: -- A pledge of 4% of the county's 5% tourist development tax (TDT) that is levied on countywide lodgings in hotels, motels, and campsites which in 1998 generated nearly $76.9 million and provided 1.62 times (x)