For years -- decades, even -- people in the IT industry have been predicting the death of the mainframe. Yet despite all the doomspeak, the mainframe's future remains bright. Enterprise-wide architecture like Business Integration and Virtualization, as well as zIIP, zAAP and IFL engines are all working to increase the potential of mainframes in a way that is just as exciting as when the mainframe first came out in the 1970s. While the old green screen terminals have been replaced with terminal emulation software, and while emerging cloud technologies continue to generate buzz, the mainframe remains the platform of choice for the majority of the world's Fortune 500 companies.
The business world is full of buzzwords but none seem to be gaining more traction in recent times than "cloud computing". But what exactly is cloud computing? There seem to be so many different definitions of what it entails that pinning down an exact definition is extremely difficult. In this article, we'll help demystify the concept of cloud computing by looking at how it is implemented in practical situations: what types of cloud services are being offered and who is using them? We'll also discuss how cloud computing is in many ways, an extension of the mainframe terminals of the 1970s, as well as the role that 3270 emulation and other emulators still play today.
Terminal emulation refers to a type of software that allows end users to access a host computer or mainframe. The original terminals of the 1960s and '70s were crude pieces of hardware that performed a single function: accessing their host. Because of these limited capabilities, terminals did not survive in the multi-functional modern computing environment. Instead, terminal emulation software was introduced to mimic the original terminal hardware on a modern PC.