TN3270 screen size is configurable.
The default screen size is 80x24, 80 columns by 24 lines, also known as a Model 2.
Changing TN3270 screen size to 132x27 is useful for viewing the z/OS system log and unix files with long lines
ISPF Settings, =0, Terminal Characteristics, Screen format must be 3, Max.
File > Session Wizard > 2. Edit Session > 4. Model Number > 5. Model 5 has 27 rows and 132 columns
Vista TN3270 (Windows)
Start a New Terminal Session > Terminal Model - select Mod 5
Options > Options > Display tab > Select Mod 5
Options > Screen Size > Model 5 (132x27)
3270 Terminal Protocol
- Existed more than a decade before the internet and HTML
- Is text only and designed for speed
- Capable of sending and receiving full screens (rows x columns) as the result enter
- Has protected screen fields, will not accept typed input, and unprotected fields, will accept typed input
- Tab key will tab to next unprotected field
- Input screen may consist of many changes and instructional commands to be processed as a result of enter