1. A computer implemented method of processing a plurality of credit card transactions through a transaction processing system, comprising: receiving the credit card transactions over a first communication link from a plurality of data sources, the credit card transactions including first priority transactions for purchase authorization requests and purchase authorization confirmations, the credit card transactions further including second priority transactions for clearing and settlement, reporting, reconciliation requests, error corrections, refund transactions, and administrative functions; separating the first priority transactions from the second priority transactions; routing the first priority transactions over a second communication link to a data destination; routing the second priority transactions to an incoming queue; storing the second priority transactions in a register of the incoming queue as a plurality of transaction files each having data contents and file attributes as defined by the data source which originated the second priority transaction to describe credit card transactions for goods or services, the register accommodating variable length files with associated start and stop locations for each file; providing a data processing system including a plurality of data processing units, each data processing unit being configured at a given time to process one type of transaction file in the incoming queue based on the data contents and file attributes as defined by the data source which originated the second priority transaction; selecting a data processing unit to process a first type of transaction file from the incoming queue by matching the data contents and file attributes of the first type of transaction file with the data processing unit which is configured to process the first type of transaction file; processing the first type of transaction file in the data processing unit configured for the first type of transaction file, the data processing unit including software for parsing the data, performing currency conversions, error checking, adding data content, reformatting data content, and performing administrative functions; re-configuring an idle data processing unit, originally configured for processing the data contents and file attributes of another type of transaction file, to process the data contents and file attributes of the first type of transaction file if a plurality of the first type of transaction files are waiting in the incoming queue; placing the second priority transactions in an outgoing queue after processing in the data processing system; and routing the second priority transactions from the outgoing queue over a third communication link to the data destination.