| In the early days of computing, mainframe users | | | | time can have a significant impact on the |
| accessed their systems using a dumb terminal. | | | | company's bottom line. |
| Dumb terminals are input/output devices with no | | | | Unlike dumb terminals, PC's are capable of |
| processing capability and only enough memory to | | | | processing data. When combined with a terminal |
| decipher particular control codes. Dumb terminals | | | | emulator, this ability allows PC users to perform |
| were most commonly found in large organizations | | | | tasks that simply weren't possible with dumb |
| with the need to process immense numbers of | | | | terminals alone. For example, with a terminal |
| data transactions, such as financial institutions. For | | | | emulator, users can print host data to local and |
| organizations like these, the processing power of | | | | network printers or to files on their PC. Data |
| the mainframe was necessary in order to | | | | being sent to and from the host can also be |
| successfully accomplish basic daily operations. | | | | processed automatically. |
| With the advent of PC's, users needed a way to | | | | Scripting can be used in conjunction with the |
| interact with their organization's mainframe from | | | | terminal emulator to automate routine tasks. More |
| their desktops. Terminal emulators were | | | | advanced terminal emulators provide the ability to |
| developed to fill this need. Using terminal emulation | | | | assign these scripts, typically referred to as |
| software installed on the PC means that only one | | | | macros, to a key on the keyboard, a keypad |
| machine is needed to access the mainframe. | | | | button, toolbar button or the mouse. One |
| Terminal emulators not only eliminate the need for | | | | example of a time-saving macro is a script that |
| a separate terminal, they also provide additional | | | | can be configured to automatically run when the |
| features that serve to extend capabilities and | | | | host session is established and dynamically enter |
| increase productivity. | | | | the user's logon details. |
| Dumb terminals use a standard set of codes to | | | | Contemporary terminal emulators may also |
| communicate with the host system. These codes, | | | | include SSL or SSH security to encrypt |
| also known as escape sequences, are responsible | | | | transactions between the PC and the mainframe. |
| for performing basic screen display functions such | | | | Server authentication and encryption provides |
| as changing colors and moving the cursor. In the | | | | secure data access across TCP/IP networks. |
| days when the use of dumb terminals was | | | | With the security of SSL or SSH, terminal |
| common, different terminal manufacturers used | | | | emulation sessions are protected from |
| different sets of standard codes. The most | | | | eavesdropping, tampering, or message forgery |
| common terminal types are 3270, 5250, VT, and | | | | over TCP/IP. This feature can be critical for those |
| SCO ANSI terminals. Many large organizations use | | | | organizations that use remote access across the |
| more than one terminal type. In most cases, one | | | | Internet to retrieve sensitive data on corporate |
| terminal emulator can be used to access a | | | | mainframes. |
| combination of terminal types, eliminating the need | | | | Although mainframe technology is decades old, it |
| for multiple dumb terminals. | | | | is still in use in countless organizations today. |
| Most modern day terminal emulators use a | | | | These organizations now use terminal emulators |
| graphical interface that is similar to the user's | | | | instead of dumb terminals to access these |
| existing PC applications. This makes using a | | | | systems. BMC Software recently conducted a |
| terminal emulator more user friendly than a | | | | survey of 1,100 IT managers whose organizations |
| traditional terminals, and decreases the learning | | | | use mainframes. 95% of the respondents |
| curve associated with host access - especially for | | | | indicated that the mainframe still plays a critical |
| new users. In large organizations where employee | | | | role in their IT infrastructure, and will continue to |
| turnover is a concern, this reduction in training | | | | do so. |