Figure
Action and screen templates
VT100 based applications often have format inconsistencies that make it difficult for the TRS to efficiently determine when the host application is ready for input and what region of the host screen contains vital information. These inconsistencies are due to the character based nature of the VT100 protocol.
In addition, the VT100 communication protocol has no way of notifying the TRS that host data transmission has ended. From the terminal operator’s perspective, it is easy to tell when host transmission ends because the operator’s requested information appears on the screen. From the TRS’s perspective, there is nothing inherent in the VT100 protocol to provide notification of the end of host output. The TRS encounters a stream of data from the host, and from this must determine the identity of each screen as well as locate the end each screen. To enable the TRS to do this, as well as cope with screen inconsistencies, you must create a file called screen.conf.