1. Apparatus for controlling the completion of tasks used to control the operation of an automated teller machine (ATM), the ATM connected to a host processing device, comprising: a plurality of peripheral devices interconnected as a part of the ATM, each of the peripheral devices including means for formatting transaction sequence event messages to initiate ATM transaction events using the peripheral devices; ATM control means connected between said ATM and said host processing device for scheduling ATM transaction events such that the peripheral devices perform at least two ATM transaction events simultaneously in real-time, the ATM control means including a first task scheduling control means for controlling the completion of tasks initiated by said ATM control means on a prioritized basis; and interface control means connected to said ATM control means and the plurality of peripheral devices for receiving and processing the transaction sequence event messages to initiate simultaneous real-time performance of the ATM transaction events by the peripheral devices, the interface control means including a second task scheduling means for controlling the completion of tasks initiated by said interface control means on a non-prioritized basis.