you would receive the CP time-of-day message, and you could no longer
use the truncation "T" for the CMS command TYPE. In order to see the
contents of a CMS file displayed at your terminal you would have to
enter at least "TI" as a truncation. CONTROLLING KEYBOARD-DEPENDENT COMMUNICATIONS You are dependent on your terminal for communication with VM/370: when
your virtual machine is waiting for a read either from the control
program or from your virtual machine operating system, you can not
receive messages until you press the Return key to enter a command or a
null line. If you are in a situation where you must wait for a message
before continuing your work, for example, if you are waiting for a tape
device to be attached to your virtual machine, you can use the CP command SLEEP to lock your keyboard:
cp sleep You must then press the Attention key to get out of sleep and unlock the
keyboard so you can enter a command.
If your virtual machine is in the CP environment when you issue the SLEEP command, or if you issue the SLEEP command from the CMS environment using the .CP function, your virtual machine is in the CP environment after you press the Attention key. If your virtual machine
is in the CMS environment when you enter the SLEEP command (or if you
enter CP SLEEP), your virtual machine is in the CMS environment when you
press the Attention key once. You can control the effect of pressing the Attention key on your
terminal with the CP TERMINAL command. If you specify:
cp terminal mode cp
then, whenever you press the Attention key, you are in the CP environment.
If you use the default terminal mode setting, which is VM, and then
you press the Attention key once, you cause a read to your virtual
machine; if you press the Attention key twice you cause a CP read, and
you are in the CP environment.
The effect of pressing the Attention key is also important when you
are executing a program. At times, you may wish to enter some CP commands while your program executes, but you do not want to interrupt
the execution of the program. If, before you begin your program you
issue the command:
cp set run on
and then use the Attention key to get to the CP environment while your
program executes, the program continues executing while you communicate
with CPa The default setting for the RUN operand of the SET command is
off; usually, when you press the Attention key (twice) during program
execution, your program is interrupted. SPECIAL CHARACTER SETS: If you are using a Frogramming language or you to use characters that are not on your
keyboard, you can select some characters that yeu do not use very often
and establish a translate table with the SET command. For example, if
your terminal does not have the special characters [and ] (which have 30 IBM VM/370 CMS User's Guide

the hexadecimal values AD and ED, respectively), you could issue the
commands:
set input % ad
set input $ bd
Then, when you are entering data lines at your terminal, whenever you
enter the characters "%" or "$", they are translated and written into
your file as "[" and "In. When you display these lines, the character
positions occupied by the special characters appear to be blanks,
because they are not available on your keyboard. If you want these
special characters to appear on your terminal in symbolic form, you
should issue the commands:
set output ad % set output bd $
so that when you are displaying lines that contain these characters,
they will appear translated as % and $ on your terminal. If you are
going to use the input and output functions together, you must set the
output character first; if you set the input character first, then you
are unable to set the output function.
If you are an APL user and have
3270 feature and keyboard, you can
tables with the command:
cp terminal apl on
the special APL type font or the APL tell VMj370 to use APL translation
Commands to Create, Modify, and Move Data Fiies
and Programs
The CMS command language provides you with many different ways of
manipulating files. A file, in CMS, is any collection of data; it is
most often a disk file, but it may also be contained on cards or tape,
or it may be a printed or punched output file. COMMANDS THAT CREATE FILES You create files in CMS by several methods; either specifically or by
default. The EDIT command invokes the CMS editor to allow you to create
a file directly at your terminal. You must specify a file identifier
when you are creating a new file:
edit mother goose
In this example, the file has an identifier, or fileid, of MOTHER GOOSE. The EDIT subcommand INPUT allows you to begin inserting lines of data or
source code into this file. When you issue the subcommands FILE or SAVE, the lines that you have entered are written into a CMS disk file.
Files are created, and sometimes named, by default, with the
following types of commands: • Commands that invoke programming language processors or compilers.
For example, if you issue the command:
assemble myfile
Section 3. What You Can Do With VMj370-CMS Commands 31