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Block Data Transfer
The cursor might be repositioned either backward or forward. For forward repositioning, the
start point is usually the start of the next unprotected or transmit-only field. When it is
repositioned backward, a search is made for one of the following: column I of the current line,
the first block terminator or non-displaying terminator, the home up position, the logical
start-of-text, or the
((Start Col"
position selected on the Terminal Configuration menu. Then
the cursor is located at this point, which becomes the start point.
When the
AutoTerm(J)
field is set to
((Yes",
the cursor is repositioned before handshaking is
done (if handshaking is selected); in fact, before even the first DCI is received from the host.
For all other menu field selections affecting cursor repositioning, the cursor is positioned after
handshaking is completed.
Cursor positioning after an •
keystroke is different from that of the send display
(Ec d)
escape sequence in that when the
((Ec d"
escape sequence is used, the cursor is never
repositioned.
END POINT SELECTION.The end point is determined by one or more ((terminating agents",
as listed below:
• Block terminator (BT).
• Non-displaying terminator (NDT).
• End of the line.
• End of the field (unprotected or transmit-only).
• End of the workspace.
In many cases, the data block can be terminated by more than one agent. In such cases, the first
agent encountered ends the block.
DATA TRANSFER. The type of data transferred depends on the current combination of
terminal modes. Data types that might be transferred are as follows:
• ASCII displayable characters.
• ASCII control codes (characters).
• Video enhancement escape sequences.
• Alternate character set escape sequences.
• Field definition escape sequences.
• Edit check escape sequences.
Field definition types include: unprotected fields, protected fields, transmit-only fields, and
security fields. Edit check types include: numeric-only, alphabetic-only, and all characters.
END CHARACTER TRANSFER. When the last character of the data block has been sent,
the terminal adds one or more ((end characters" to the data block. These are as follows:
• Block terminator.
• Carriage return.
• Line feed (if enabled).
The type of end character(s) transmitted depends on the terminal mode combination.
9-8
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