Tandy 1000 Basic Reference Manual page 305

Chapter
10 I BASIC
Ke.ywords
SCREEN
Statement
SCREEN [model[, [burst][, [active pagel[,dispZay page11
[,erasell
Sets the screen attributes to be used by all other graphics state-
ments (CIRCLE, LINE, DRAW, POINT, PSET, PRESET, PAL-
ETTE, and PALETTE USING).
Mode is a n integer in the range 0 to 6 that sets the valid coordi-
nates and the number of colors you can use. Screen Mode de-
scriptions a r e given i n Chapter 8, "Displaying Color and
Graphics
."
When you change from one mode to another, BASIC stores the
new screen mode, erases the video display, and sets the fore-
ground color to white and the background and border colors to
black.
Burst
enables or disables color. In Screen Mode 0 (text mode), set
burst
to 0 to disable color or 1 to enable color. In medium resolu-
tion (Screen Modes 1 and 4), set
burst
to 0 t o enable color or 1 to
disable color.
Burst
has no effect in high and low resolution
(Screen Modes 3, 5, and 6) where color is always enabled or in
Screen Mode 2, which is black and white.
Active page
is a n integer that selects the video page to which
BASIC will write. All output statements to the screen go t o the
selected
active page.
The range depends on the screen mode and
the amount of video memory available. If you omit
active page,
BASIC assumes the current active page.
Active page
is initially
set to Page 0.
Display page
is a n integer that selects the video page for BASIC
to display. The range is the same as
active page.
If you omit
dis-
play page,
BASIC uses the same page
as active page.
BASIC au-
tomatically sets
display page
to
active page
if the program halts
because of an END or STOP statement or because of an error.
All video pages share one cursor. Therefore, when switching ac-
tive pages, you should save the cursor position with the POS and
CSRLIN statements. Then when you return to a n active page,
you can restore the cursor with the LOCATE statement.
303