Over the years, more enhancements were made to the cash registers until the early 1970s, when the first computer-driven cash registers were introduced.
The first computer-driven cash registers were basically a mainframe computer packaged as a store controller that could control certain registers. These point of sale systems were the first to commercially utilize client-server technology, peer-to-peer communications, Local Area Network (LAN) backups, and remote initialization.
In the late 1980s, retail software based on PC technology began to make its way into mainstream retail businesses. Today, retail point of sale systems are light years ahead of where they began. Today's POS systems are faster, more secure, and more reliable than their predecessors, and allow retailers to operate every facet of their business with a single, integrated point of sale system. (http://www.retailsystems.com/history-of-retail-pos-systems.cfm)
Since computer power was the critical resource, efficiency of processing became the main goal. Emphasis was placed on automating existing process such as purchasing or paying, often within single department as indicated by Jeffrey A. Hofer on Modern System Analysis and Design (1996).
Points of sale (POS) systems are electronic systems that provide businesses with the capability to retain and analyze a wide variety of inventory and transaction data on a continuous basis. POS systems have been touted as valuable tools for a wide variety of business purposes, including refining target marketing strategies; tracking supplier purchases; determining customer purchasing patterns; analyzing sales (on a daily, monthly, or annual basis) of each inventory item, department, or supplier; and creating reports for use in making purchases, reorders, etc. Basic points of sale systems currently in use include standalone electronic cash registers, also known as ECRs; ECR-based network systems; and controller-based systems. All