For every line in display memory, the Host Integrator attempts to remember the leftmost column that was entered from the keyboard, as opposed to that received from datacomm. This way, the Host Integrator can distinguish the host prompt portion of each line from the user-entered portion. This information is used when you enable LINE MODIFY or MODIFY ALL to determine the leftmost column that should be transmitted to the host when you press Enter or Return.
Under some circumstances, it is impossible for the Host Integrator to tell which column was the first user-keyed column; when that happens, it uses the value you enter in this box to determine the leftmost column to be transmitted. When Display Columns are set to 80, enter a value from 0 to 79. When you're in 132-column mode, enter a value from 0 to 131.
The values are 0-131. The default is 0.
Note: This setting is saved as part of the model's default settings, and will be used when initially connecting or resetting a session. Another setting, HP Start Column, reflects the current terminal state, which can be changed by the host.