and the resulting data to be processed is:'
/sos tabcmd I I, abc I' The SOS facility recognizes only two types of data; SOS commands and data
to be typed on the I/O virt!lal screen. As each logical line is obtained from
the eMS console stack, a check is make to determine if it contains a valid SOS command. A valid sos command is defined as one which starts in position
one (1) of the logical line, begins with the characters "/ sos ", and has as its
first operand a recognized sos command. If the logical line does contain a
valid sos command, the rest of the line is returned to the eMS console stack
and the command is executed. If the logical line does not contain a valid sos
command, it is considered to be data and is placed on the I/O virtual screen at
the current position of the virtual cursor. The cursor position is then incre­
mented once for each character so inserted.
sos continues to process the eMS console stack until the stack is empty _or it
reads a "null" entry (an entry with zero length). At that time, it relinquishes
control of the I/o virtual screen which is subsequently written to the physical
display device.
Note: It is important for the user to recognize that changes made to the I/O virtual screen by the sos facility have exactly the same effect as those made
by the user on his display terminal. In fact, except for the I/o Processor, the
editing system has no knowledge of the source of changes to the 1/0 virtual
screen.
Advanced Editing Facilities 44

SOS COlnmands All sos commands are prefixed by the characters "/ SOS ". TIW description
of each command, below, conforms to the following format: uppercase
characters indicate the shortest allowable form of the command, while the
lowercase letters complete the command.
ALarm
Attn
BField n CLEAR CONTinue Down n
DELete n
ENTER
ERAseof
ERRor Continue
ERRor VERIFY ERRor ESCAPE EXec xxx p r INsert Ring the terminal alarm when, and if, this screen is written
to the physical display terminal.
If the NOREAD setting is on, perform the same function as /SOS ENTER. If the NO READ setting is off, perform the
same function as a "null" entry in the stack (display the
virtual screen on the physical display terminal).
Reposition the cursor as per the back field key. The key is
to be depressed n times. The default is one (1). - Clears the eMS console stack and thus will terminate SOS activity and display the virtual screen on the physical ter­
minal.
Implies processing is to continue.
Move the cursor down n lines on the virtual screen. The
default is one (1).
Delete n characters at the position of the cursor from the 3270 field. The default value for n is one (1).
Depress the ENTER key. This will cause the I/O virtual
screen to be mapped to the active level virtual screens and
thus processed by the Display Processor. It is not until
this key is depressed that any changes can be made to the
data file.
Depress the ERASE EOF key. Erase the data until the end
of this 3270 screen field.
If an error message is found on an edit level virtual screen,
ignore it and continue processing
If an error message is found on an edit level virtual screen,
issue the sos "error encountered" message and terminate
sos activity (do not purge the console stack however).
If an error message is found on an edit level virtual screen,
issue the sos "error encountered" message, terminate sos
activity, and purge the eMS console stack.
Execute exec xxx and pass to it the parameters p and r.
Insert turns on insert mode. Insert mode will be on for the
duration of one (1) logical line (the next one). After that
an automatic reset is issued. Data may be inserted only
within fields for which NULLS have been set on.
Advanced Editing Facilities 45