IBM W2H Vertical-scroll display control mode 12 DC2, Cursor on 13 DC3, Cursor off 14 DC4, Purpose

11-9-2005 Input/output device commands

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:

vCursor on.

vScrolling alphanumeric message off.

vAll character positions filled with X'20'.

vWrite position for next write at position X'00' (top left).

vDefault code page (437) selected.

vDC2 mode enabled.

vDefault (Logic Controls) emulation mode selected.

vBrightness set to 100%.

vIBM 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.

Appendix A. Input/output device commands A-7