A system and method for conveying data include the capability to determine whether a transaction request credit has been received at a computer module, the transaction request credit indicating that at least a portion of a transaction request message may be sent. Brushes secured onto flexible, brush holders urge the brushes towards the central passage into a contact position with the commutator. In one embodiment all or a portion of the available memory is divided into smaller pages that are preferably equal in size. The size of a fragment does not exceed the capacity of the conveying network. The central region of the chamber is elevated with respect to the periphery of the chamber floor adjacent the chamber side wall and may be convex or conical, with the chamber floor periphery defining a vortex flow path.