Reshow key processing in full-screen mode

GDDM V3R2 Base Application Programming Guide

Reshow key processing in full-screen mode

GDDM V3R2 Base Application Programming Guide
SC33-0867-01

Under TSO, GDDM operates an IBM 3270 series display in what is known as "full-screen mode". In this mode, if the terminal is to receive a non-full-screen message, such as an error message, or a message from another TSO user, the display screen is cleared, the alarm is sounded (if applicable), and the message is displayed.

If several such messages occur consecutively, the screen is cleared once, the alarm is sounded, and the messages are displayed in sequence. When the next GDDM full-screen transmission is received, a paging condition (indicated by three asterisks, ***, at the current line) is forced.

Pressing the ENTER key at this point queues a request to GDDM to completely retransmit the display buffer contents to the terminal (this is equivalent to the call FSREST(1)). Note that GDDM receives this reshow request only if it is (or when it is next) testing for input as a result of a call to ASREAD, FSSHOR, FSSHOW, GSREAD, MSREAD, or FSFRCE. TSO protocols are such that more partial GDDM transmissions may occur before GDDM starts retransmission of the contents of the buffers.

Using the reshow key (by default, PA2) during normal full-screen processing simulates the above conditions and causes GDDM to retransmit the contents of the buffers.

The TSO Reshow protocol option of the DSOPEN function can be used to define a key other than PA2 to act as the reshow key.

Notices | Terms of use | Support | Contact z/OS