This invention relates to a casino gambling system that includes a plurality of casino gambling units that allow customers to play casino gambling games such as poker and blackjack. 
FIG.  1 illustrates a prior art casino gambling system 10 that was commercially utilized more than one year prior to the filing date of this patent by International Game Technology, the assignee of this patent.  Referring to FIG.  1, the prior art system 10, a portion of which is referred to as the “EZ Pay” system, included a plurality of gambling units 12, which were provided in the form of conventional gambling machines, such as machines that allowed casino customers to play casino games such as video poker, video blackjack, video slots, etc. 
The gambling units 12 utilized ticket vouchers that were used as a medium of value and that could be exchanged for cash after being validated.  For example, in the case where a gambling unit 12 was a slot machine, instead of dispensing winnings in the form of coins, the slot machine would issue a ticket voucher, which was generated by a ticket printer disposed in the slot machine.  Various types of ticket vouchers were used.  For example, ticket vouchers were utilized as cash vouchers, which could be redeemed for cash, or as gaming vouchers, which could be utilized to make wagers while using the gambling units 12. 
Before being redeemed or cashed by a casino customer, a ticket voucher needed to be validated.  The ticket voucher could be validated by inserting it into one of a plurality of clerk validation terminals (CVT) 14, with each of the CVTs 14 being operatively connected to a group of gambling units 12.  The validation was performed by comparing information read from the ticket voucher with information stored in the CVT 14, which information could be transmitted to the CVT 14 from the gambling units 12 to which it was operatively coupled.  After a ticket voucher was cashed out, the CVT 14 stored in its memory information identifying the paid ticket voucher to prevent a ticket voucher from being cashed more than once.  Such validation process could only be performed by the CVT 14 operatively coupled to the gambling unit 12 which issued the ticket voucher. 
To allow more flexibility in validating ticket vouchers, the CVTs 14 were connected to a concentrator 16, which was in turn connected to a front-end controller 18 coupled to a server computer 20.  The server computer 20 was connected to a plurality of cashier computers 22 and an audit computer 24 via a networked data link 26.  The connection of the front-end controller 18 and the concentrator 16 to multiple CVTs 14 allowed data regarding the ticket vouchers generated by all of the gambling units 12 to be concentrated at the server computer 20. 
Due to the connection of the cashier computers 22 to the server computer 20, customers could also present ticket vouchers to cashiers for validation and redemption.  In that case, the cashier to whom a ticket voucher was presented would insert the ticket voucher into a cashier computer 22, and the computer 22 would validate the ticket voucher by comparing data optically read from the ticket voucher with data retrieved from the gambling unit 12 that issued the ticket voucher.  After validation of a ticket voucher, validation information was transmitted to the audit computer 24, which performed various audit operations.  The server computer 20 was also connected to an administration computer 28 and an accounting computer 30 for other functions to be performed. 
Before a cashier was allowed to use a cashier computer 22 to perform ticket validation and other functions, the cashier was required to logon to the cashier computer 22 by entering a user identification number and a password for security purposes.  Some operations performed by the cashier using the cashier computer 22 required the authority of a supervisor, in which case the supervisor needed to enter a password before the operations could be performed.