The Keyboard; Command And Function Key Codes; Figure 1.2 The Data Entry Keyboard - IBM 5280 Programmer's Manual

The Keyboard
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The Keyboard
This section describes the function and command keys, and their interaction
with COBOL programs and the IBM 5280 system. The chapter is intended
primarily for the COBOL programmer. For a tutorial, with a detailed
explanation of the use of each key, the operator should look at the Operator's
Guide.
Figure 1.2 shows a data entry keyboard.
The relative positions of most of the keys on the other keyboards available
with IBM 5280, are the same as on the data entry keyboard. For a detailed
description of all keyboards, see the Operator's Guide.
For descriptive purposes, the keys can be classified as data keys,junction
keys, and command keys.
• Data keys, when pressed, cause entered data to be processed by your
COBOL program or the system.
• Function keys, when pressed, cause the IBM 5280 system to take some
action.
• Command keys, when pressed, give control to your COBOL program. A
code showing which key was pressed is passed to a control area, if
specified, in the program.
Figure 1.2 The data entry keyboard
In general, the function keys shown in figure 1.1 are colored dark, and the
data keys are white. The operator presses a function key to enter the desired
data or execute a desired function. Additionally, the top row of data keys can
also be used as function keys or command keys. The next two sections
describe the use of these keys and how they affect your COBOL programs.
Command and Function Key Codes
The following codes are returned in the work station control area (described
under "Work Station Control Area" in Chapter 3) to your program when it
receives control from the work station:
• 0 when either the Enter or Record Advance key is pressed.
• 99 when any other function key is pressed.
Chapter I. Transaction I/0 - Introduction 1- 5