The text modes use a coordinate system that divides the screen into rows and columns as shown in the following figure:
Text coordinates use the following conventions:
Numbering starts at 1. An 80-column screen contains columns 1-80.
The row is always listed before the column.
If the screen displays 25 rows and 80 columns (as shown in the above Figure), the rows are numbered 1-25 and the columns are numbered 1-80. The text-positioning routines, such as SETTEXTPOSITION and SCROLLTEXTWINDOW, use row and column coordinates.