To Read Data From And Write Data To The Display Screen - IBM 5110 User Manual

For example:
CTL~'INR
11005 ID=(DIRECT) MSG=OFF'
Cll .. ,
o
x
Do not display the error messages.
The file identification.
The data is on diskette drive 1, file 5.
Read-only data from a direct access data file.
The second element of the return code identifies the number of
records in the data file.
See To Update a Direct Access Data File for a description of how
records are read from a direct access data file.
To Read Data from and Write Data to the Display Screen
Reading and writing data on the display screen is similar to reading
and writing data on a direct access data file. That is, the operation
requires a pair of shared variables, with one of the shared variables
having the prefix CTL and the other having the prefix OAT. You
specify the operation as follows:
CTL~'DISPLAY
[MSG=OFFJ'
1
The error messages are not displayed.
Read or write data on the display screen.
A pair of shared variables is used for reading and writing
data to the display screen.
Once the operation is specified, the CTL shared variable is used to
specify what character positions to read or write. To do this you must
assign a two- or three-element vector to the CTL shared variable, as
follows:
CTL
+-
0 starting character number [number of characters] L
1
If this elemLt is not
o
specifies a read data operation. specified, one character
1 specifies a write data operation. is assumed.
I nput/Output Control 133