Texas Instruments TI-89 Tip List page 343

The first syntax writes a single string. The second syntax writes the strings as multiple lines. The third
syntax writes expressions, or lines of text mixed with expressions. The square brackets indicate that
the arguments font_size and mode are optional and need not be included. However, if you include the
mode argument, you must also specify the font_size argument.
x and y specify the starting position of the text in pixel coordinates. x is the column coordinate, and y is
the row coordinate. The upper left coordinate of the screen has coordinates x = 0 and y = 0. Negative
values of x and y cause the string to be displayed outside of the visible screen area.
string specifies the string to be displayed.
font_size specifies the size of the displayed text:
0 = small
1 = medium (the 'normal' font size; default)
2 = large
mode specifies one of five settings which control the appearance of the displayed text:
0 = white text on black background (over-write mode)
1 = black text on white background (OR mode; default)
2 = black text on white background (XOR mode)
3 = gray text on white background
4 = black text on white background (over-write mode)
In over-write mode, the text and background replace any pixels previously displayed . In OR mode, the
text and background pixels are logically OR'd with existing pixels, which means that the pixel at a given
location will be 'on' (black) if the previous pixel or the text pixel is on. In XOR mode, the resulting pixel
is off only if the original background pixel and the text pixel are the same. The over-write mode could
be considered an 'opaque' mode, while the OR mode is a 'transparent' mode.
The third syntax and its arguments are described in an example below, after some examples for the
first two syntaxes.
Syntax 1 example: Single lines, different font sizes, black and gray text
This example uses the first syntax to display some sample text in three font sizes, with modes 1 and 3.
clrio
"ABCDEFGHIJKLMNOPQRSTUVWXYZ"→s
disp
util\write(60,3,s,0,1)
util\write(40,12,s,1,1)
util\write(10,23,s,2,1)
util\write(60,40,s,0,3)
util\write(40,49,s,1,3)
util\write(10,60,s,2,3)
© Clear Program I/O screen
© Display Program I/O screen
© Write lines in mode 1 (black on white)
© Write lines in mode 3 (gray)
7 - 54