Pathway/iTS TCP and Terminal Programming Guide

Programming for Specific Terminals
Compaq NonStop™ Pathway/iTS TCP and Terminal Programming Guide—426751-001
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Using Simulated Devices
•
The following special registers have no meaning for programs that communicate
with intelligent devices:
•
In order for a SCREEN COBOL program unit to communicate with an intelligent
device, the OBJECT-COMPUTER paragraph of the Environment Division must
specify that the terminal type is INTELLIGENT. In addition, the PATHMON
environment must be configured for intelligent devices; this is accomplished by
setting the terminal type in a SET TERM or SET PROGRAM command. Refer to
the Compaq NonStop™ Pathway/iTS System Management Manual for details.
Using Simulated Devices
Compaq provides the means for you to write nonprivileged programs that function as a
terminal, printer, tape driver, or other device. In the terminology of the Compaq
NonStop™ Kernel operating system, these programs are called subtype 30 processes.
Specifying device subtype 30 tells the system that the terminal-simulation process will
supply device information in response to a request for the device-type information.
Hence device subtype 30 must be specified for a terminal-simulation process; otherwise,
the file system will reply to the DEVICEINFO request.
All the devices that Pathway/iTS interfaces with can be emulated with a subtype 30
process. The device list includes:
•
Terminals
RUN PROGRAM terminals have a DEVICEINFO time limit of five minutes.
START TERM terminals do not have a DEVICEINFO time limit.
•
Log files
Log files have a DEVICEINFO time limit of two minutes if PATHMON is starting.
However, log files have a time limit of five minutes if PATHMON is running.
•
Associative servers
Associative servers have a DEVICEINFO time limit of five minutes.
When a DEVICEINFO error occurs, an error is not logged. Instead, the following error
message is sent to the operator:
ERROR - *1040* UNABLE TO DETERMINE DEVICE TYPE (nnn)
where nnn is an operating system error.
REDISPLAY
PW-QUEUE-FKEY-UMP
PW-QUEUE-FKEY-TIMEOUT
PW-TERMINAL-ERROR-OCCURRED
TELL-ALLOWED