IBM 31x, Installation And Service Manual, Page: 39 / 68

Vertical-scroll display control mode (12) <DC2>
12
Purpose:
Sets vertical-scroll display control mode (DC2) and permits data to be
written to either line. When the display position is at the last position of the
top line, the cursor moves to the first position of the bottom line. When
either valid character data or a Horizontal Tab command is sent to the last
position of the bottom line, the data on the bottom line is transferred to the
top line and the cursor is moved to the lower left position. Note that a
Carriage Return command does not cause the data on the bottom line to be
transferred to the top line. This mode is the default setting for power on and
reset. The display remains in DC2 mode until a DC1 mode command is
issued.
Cursor on (13) <DC3>
13
Purpose:
Turns on the cursor. The command is the power-on default setting.
Cursor off (14) <DC4>
14
Purpose:
Turns off the cursor.
Reset (1F) <US>
1F
Purpose:
Causes the display to reset some programmable parameters to the
power-on state, which is defined as:
v
Cursor on.
v Scrolling alphanumeric message off.
v
All character positions filled with X'20'.
v
Write position for next write at position X'00' (top left).
v Default code page (437) selected.
v
DC2 mode enabled.
v Default (Logic Controls) emulation mode selected.
v
Brightness set to 100%.
v IBM user-defined characters not erased. The Logic Controls user-defined,
character key is reset.
All byte values between X'00' and X'1F' not defined in this section are ignored by
the display in Logic Controls mode. User-defined characters in the IBM mode that
have not been defined previously are spaces.
Input/output device commands
11-9-2005
Appendix A. Input/output device commands
A-7