© 1985 ASCII CORP. / NIPPON GAKKI CO.
Page 95 of 108
© 2010-2015 Eugeny Brychkov
5. SPRITES
MSX-VIDEO can display up to 32 sprites on the screen. Depending on the sprite mode,
sprite sizes can be 8*8 or 16*16 dots. X-axis coordinate of sprite location is always
between 0…255, and this means that in graphics modes with 512 dots on the X-axis single
sprite’s dot occupy two horizontal dots of the screen.
Sprites can be placed anywhere on the screen. Sprites are processed independently of
and do not affect other graphics. They can be independently switched on or off.
The following diagram conceptually shows how sprites are displayed. Note that visible
screen area may have 192 or 212 pixels depending on the setting of LN bit of register R#9,
and visible screen area can be vertically scrolled using vertical offset register R#23.
(0, 255*)
(255, 255*)
(X,Y)
Sprite
Sprite
Visible screen area
(0, 191) or
(0, 211)
Invisible screen area
(255,191) or
(255, 211)
Sprite
(0, 254)
(255, 254)
* They Y-coordinate of the upper edge of the sprite screen is 255
The MSX-VIDEO can work in two sprite display modes. Respective mode is selected
during initialization of the screen mode.
•
Sprite mode 1: GRAPHIC1, GRAPHIC2, MULTICOLOR
•
Sprite mode 2: GRAPHIC3 … GRAPHIC7
Sprites are not available in TEXT1 and TEXT2 modes.