Field-Oriented Screens
The 5250 screen buffer contains 24 lines by 80 columns and is generally field-oriented (formatted), or organized by fields.
The 3270 screen buffer can have different display models:
Mod Number |
Screen Size |
Mod 2 |
24 x 80 |
Mod 3 |
32 x 80 |
Mod 4 |
43 x 80 |
Mod 5 |
27 x 132 |
Most of the ECS subroutines are written to access field-oriented screens. accesses the screen buffer by first assigning sequential numbers to each field in the buffer. By specifying a field number, you can retrieve that field's contents and associated attributes, or write text into the specified field.
Line-Oriented Screens
Sometimes, a 3270/5250 application contains screens in which each line is a field of its own, or contains screens that have no fields at all. These are called line-oriented (unformatted) screens.
There are two ECS subroutines used to access line-oriented screens:
You can use these subroutines to access line-oriented or field-oriented screens, but you cannot use field-oriented subroutines to access line-oriented screens.