The 3270 protocol was designed in the 1970s to communicate between "green screen" terminals and IBM mainframes. 3270 terminals are no longer manufactured; the protocol lives on in emulator software used to access IBM mainframe services that do not yet have web (or other) interfaces.
The 3270 protocol was designed in the 1970s to communicate between "green screen" terminals and IBM mainframes. 3270 terminals are no longer manufactured; the protocol lives on in emulator software used to access IBM mainframe services that do not yet have web (or other) interfaces.
It is possible to "screen scrape" a 3270 emulator. This technique originated in the 1980s with the advent of such emulators. At that time, the mechanism used was to send commands to the emulator via the High Level Language Application Programming Interface (HLLAPI). HLLAPI was later enhanced, and one began to hear of EHLLAPI.
In either case, the intent was (and still is) to make use of existing mainframe applications, but to create a more friendly user interface. In some cases, a mashup of multiple applications can be developed.
Such applications come with a price: they are wedded to the 3270 interface. If the interface changes, the screen scraping application must change.
Today, there are more modern mechanisms available to interface with mainframe applications - provided the owners of those applications are willing to have them upgraded to use the mechanisms. If not, sometimes screen scraping is the only viable option.
