HP Data Entry and Forms Management System (VPLUS) Reference Manual (32209-90024)

610 AppendixG

TERMINAL INFORMATION

ADVANCED TERMINAL I/O PROCEDURES

In general, the VPLUS terminal input/output procedures such as VOPENTERM,

VCLOSETERM, VREADFIELDS and VSHOWFORM are sufﬁcient for most applications that

communicate with a user via a terminal interface.

In building complex user interfaces, however, application designers have a limited number

of tools for implementation. Hence, they resort to using FREAD, FWRITE, and input/output

verbs of their programming language to display and retrieve information from the

terminal when running VPLUS. The situation becomes more complicated when the

application controls the terminal settings as well as the driver settings, and is likely to

result in an application that runs in a restricted environment; for example, on an ATP an

on one kind of terminal only.

VPLUS provides two additional procedures that help application designers to write

applications with complex user interfaces that are more portable and easier to maintain.

They are VTURNON and VTURNOFF.