QB中的图像代码 ［screen命令］

SCREEN - a graphics statement that sets the specifications for the
display screen

Syntax
SCREEN [mode] [,[colorswitch]][,[apage]][,[vpage]]
☆mode is an integer constant or expression that selects a screen mode
for a particular combination of display and adapter:

MDPA, CGA, EGA, or VGA (Text Only)
CGA, EGA, VGA, or MCGA Low- and Medium-Resolution Graphics
EGA and VGA Medium- and High-Resolution Graphics
EGA and VGA Monochrome High-Resolution Graphics
VGA and MCGA High-Resolution Graphics
Hercules and Other Adapters
☆colorswitch, apage, and vpage are Details



SCREEN 0: Text mode only
☆Either 40 x 25, 40 x 43, 40 x 50, 80 x 25, 80 x 43, or 80 x 50 text format
with 8 x 8 character box size (8 x 14, 9 x 14, or 9 x 16 with EGA or VGA)
☆16 colors assigned to 2 attributes
☆16 colors assigned to any of 16 attributes (with CGA or EGA)
☆64 colors assigned to any of 16 attributes (with EGA or VGA)

SCREEN 1: 320 x 200 graphics
☆40 x 25 text format, 8 x 8 character box
☆16 background colors and one of two sets of 3 foreground colors assigned
using COLOR statement with CGA
☆16 colors assigned to 4 attributes with EGA or VGA
SCREEN 2: 640 x 200 graphics
☆80 x 25 text format with character box size of 8 x 8
☆16 colors assigned to 2 attributes with EGA or VGA

SCREEN 7: 320 x 200 graphics
☆40 x 25 text format, character box size 8 x 8
☆32K page size, page ranges are 0-1 (64K), 0-3 (128K), or 0-7 (256K)
☆Assignment of 16 colors to any of 16 attributes
SCREEN 8: 640 x 200 graphics
☆80 x 25 text format, 8 x 8 character box
☆64K page size, page ranges are 0 (64K), 0-1 (128K), or 0-3 (246K)
☆Assignment of 16 colors to any of 16 attributes
SCREEN 9: 640 x 350 graphics
☆80 x 25 or 80 x 43 text format, 8 x 14 or 8 x 8 character box size
☆64K page size, page range is 0 (64K);
128K page size, page range is 0 (128K) or 0-1 (256K)
☆16 colors assigned to 4 attributes (64K adapter memory), or
64 colors assigned to 16 attributes (more than 64K adapter memory)

SCREEN 10: 640 x 350 graphics, monochrome monitor only
☆80 x 25 or 80 x 43 text format, 8 x 14 or 8 x 8 character box size
☆128K page size, page range is 0 (128K) or 0-1 (256K)
☆Up to 9 pseudocolors assigned to 4 attributes

SCREEN 11
☆640 x 480 graphics
☆80 x 30 or 80 x 60 text format, character box size of 8 x 16 or 8 x 8
☆Assignment of up to 256K colors to 2 attributes
Screen 12
☆640 x 480 graphics
☆80 x 30 or 80 x 60 text format, character box size of 8 x 16 or 8 x 8
☆Assignment of up to 256K colors to 16 attributes
☆VGA required
Screen 13
☆320 x 200 graphics
☆40 x 25 text format, character box size of 8 x 8
☆Assignment of up to 256K colors to up to 256 attributes

SCREEN 3: Hercules adapter required, monochrome monitor only
☆720 x 348 graphics
☆80 x 25 text format, 9 x 14 character box
☆2 screen pages (1 only if a second display adapter is installed)
☆PALETTE statement not supported
SCREEN 4:
☆Supports Olivetti (R) Personal Computers models M24, M240, M28,
M280, M380, M380/C, M380/T and AT&T (R) Personal Computers 6300
series
☆640 x 400 graphics
☆80 x 25 text format, 8 x 16 character box
☆1 of 16 colors assigned as the foreground color (selected by the
COLOR statement); background is fixed at black.