AM3270/TR3271 Reference Manual

Details of the ITI Protocol
AM3270 Subdevice Protocols
4–2 086705 Tandem Computers Incorporated
Subdevice Information The following information pertains to the AM3270 ITI protocol in the 3650/6100 CSS
environment:
The BREAK function is simulated by the PA1 key.
The end-of-file operation (CTRL-Y character) is simulated by the PA2 key. The
EOF! is displayed on the screen. Also, note that if TRANSLATE is enabled (see the
ALTER command in the SCF Reference Manual for AM3270 and TR3271), and the
standard translation table is used, the EOF! will be displayed as EOF|.
The Fix (FC) command works normally.
The EDIT program’s Fix (FC) command works normally. However, if a line has
more than 80 characters, it is displayed in two parts with a space between the two
parts. When using the Fix (FC) command to modify the second part, the cursor
should be moved one extra character position to the left.
Backspace and line delete characters are terminal local operations and are not
handled by the protocol.
The protocol maintains an output line count and cursor address. The output data
is displayed in wrap-around fashion. A screen separator in the form of a line of
equal signs (=) is used to indicate the bottom of the screen and is updated each
time a READ or WRITEREAD is completed.
When the line count indicates the screen is full (that is, the next outbound data
overwrites the data just written), the protocol prompts for depression of the ENTER
key. If the ENTER key is selected, the display is continued. If a BREAK (PA1) key is
selected, the protocol treats the selection as a BREAK and passes it to the application
program. If a CTRL-Y (PA2) key is selected, the protocol treats the selection as a
control Y and passes it to the application program.
The two-step READ is not supported for block mode.
The FIELD MARK key character is translated into a backslash (\).
Applicable File-System
Procedures
For AM3270/ITI protocol, the following file-system procedures are recognized:
AWAITIO DEVICEINFO SETMODE
CANCEL FILEINFO SETPARAM
CONTROL OPEN WRITE
CLOSE READ WRITEREAD
Note that all file-system procedures are documented in the System Procedure Calls
Reference Manual. File system procedures CONTROL 11 and 12, READ, SETMODEs 8,
11, 12, and 20, SETPARAM 3, WRITE, and WRITEREAD have special significance for
this protocol and are also discussed in this section.