WonderWitch/FreyaBIOS/Display

The Display interrupt provides an abstraction layer and helpers for the WonderSwan's display hardware.

Note that features specific to the WonderSwan Color are implemented using libwwc, which is linked statically with the user program and thus not part of the BIOS call surface.

Interrupts

INT $12/AH=$00 - display_control

• AH = $00
• BX = Display Control value

INT $12/AH=$01 - display_status

• AH = $01

Return:

• AX = Display Control value

INT $12/AH=$02 - font_set_monodata

• AH = $02
• BX = Starting tile
• CX = Tile count
• DS:DX = Input data buffer (8 x Tile count bytes)

Stores 1 bit-per-pixel tile data, which is expanded to 2 bits-per-pixel using the configured color.

INT $12/AH=$03 - font_set_colordata

• AH = $03
• BX = Starting tile
• CX = Tile count
• DS:DX = Input data buffer (16 x Tile count bytes)

Stores 2 bit-per-pixel tile data.

INT $12/AH=$04 - font_get_data

• AH = $04
• BX = Starting tile
• CX = Tile count
• DS:DX = Output data buffer (16 x Tile count bytes)

Retrieves 2 bit-per-pixel tile data.

INT $12/AH=$05 - font_set_color

• AH = $05
• BX = Color

15  bit  8  7  bit  0
 ---- ----  ---- ----
 .... ....  .... bbff
                 ||||
                 ||++- Foreground color (0-3)
                 ++--- Background color (0-3)

Used by font_set_monodata.

INT $12/AH=$06 - font_get_color

• AH = $06

Return:

• AX = Color

INT $12/AH=$07 - screen_set_char

• AH = $07
• AL = Screen (0, 1)
• BL = Top-left tile X coordinate
• BH = Top-left tile Y coordinate
• CL = Width, in tiles
• CH = Height, in tiles
• DS:DX = Input tilemap buffer (2 x Width x Height bytes)

Places a rectangular tilemap on the specified screen.

INT $12/AH=$08 - screen_get_char

• AH = $08
• AL = Screen (0, 1)
• BL = Top-left tile X coordinate
• BH = Top-left tile Y coordinate
• CL = Width, in tiles
• CH = Height, in tiles
• DS:DX = Output tilemap buffer (2 x Width x Height bytes)

Retrieves a rectangular tilemap from the specified screen.

Special case: If CL/CH are equal to 0, DS:DX is ignored and instead AX is set to the tile at coordinates (BL, BH).

INT $12/AH=$09 - screen_fill_char

• AH = $09
• AL = Screen (0, 1)
• BL = Top-left tile X coordinate
• BH = Top-left tile Y coordinate
• CL = Width, in tiles
• CH = Height, in tiles
• DX = Tile attribute

Fills a rectangular area with the specified tile attribute.

INT $12/AH=$0A - screen_fill_attr

• AH = $0A
• AL = Screen (0, 1)
• BL = Top-left tile X coordinate
• BH = Top-left tile Y coordinate
• CL = Width, in tiles
• CH = Height, in tiles
• DX = Tile data
• SI = Tile mask

Modifies each tile in the specified rectangular area as follows: tile = ((tile & SI) | DX).

INT $12/AH=$0B - sprite_set_range

• AH = $0B
• BX = Sprite Table First
• CX = Sprite Table Count

INT $12/AH=$0C - sprite_set_char

• AH = $0C
• BX = Sprite ID in table (0 - 127)
• CX = Sprite attribute

INT $12/AH=$0D - sprite_get_char

• AH = $0D
• BX = Sprite ID in table (0 - 127)

Return:

• AX = Sprite attribute

INT $12/AH=$0E - sprite_set_location

• AH = $0E
• BX = Sprite ID in table (0 - 127)
• DL = X coordinate
• DH = Y coordinate

Note that DL/DH are swapped relative to the order in which the sprite coordinate bytes are stored in memory.

INT $12/AH=$0F - sprite_get_location

• AH = $0F
• BX = Sprite ID in table (0 - 127)

Return:

• AL = X coordinate
• AH = Y coordinate

INT $12/AH=$10 - sprite_set_char_location

• AH = $10
• BX = Sprite ID in table (0 - 127)
• CX = Sprite attribute
• DL = X coordinate
• DH = Y coordinate

INT $12/AH=$11 - sprite_get_char_location

• AH = $11
• BX = Sprite ID in table (0 - 127)

Return:

• AX = Sprite attribute
• DL = X coordinate
• DH = Y coordinate

INT $12/AH=$12 - sprite_set_data

• AH = $12
• BX = Initial sprite ID in table (0 - 127)
• CX = Sprite count
• DS:DX = Input data buffer (4 x Sprite count bytes)

INT $12/AH=$13 - screen_set_scroll

• AH = $13
• AL = Screen (0, 1)
• BL = Screen Scroll X value
• BH = Screen Scroll Y value

INT $12/AH=$14 - screen_get_scroll

• AH = $14
• AL = Screen (0, 1)

Return:

• AL = Screen Scroll X value
• AH = Screen Scroll Y value

INT $12/AH=$15 - screen2_set_window

• AH = $15
• BL = Screen 2 Window Left value
• BH = Screen 2 Window Top value
• CL = Window width
• CH = Window height

INT $12/AH=$16 - screen2_get_window

• AH = $16

Return:

• AL = Screen 2 Window Left value
• AH = Screen 2 Window Top value
• DL = Window width
• DH = Window height

INT $12/AH=$17 - sprite_set_window

• AH = $17
• BL = Sprite Window Left value
• BH = Sprite Window Top value
• CL = Window width
• CH = Window height

INT $12/AH=$18 - sprite_get_window

• AH = $18

Return:

• AL = Sprite Window Left value
• AH = Sprite Window Top value
• DL = Window width
• DH = Window height

INT $12/AH=$19 - palette_set_color

• AH = $19
• BX = Palette index (0 - 15)
• CX = LCD Mono Palette value

INT $12/AH=$1A - palette_get_color

• AH = $1A
• BX = Palette index (0 - 15)

Return:

• AX = LCD Mono Palette value

INT $12/AH=$1B - lcd_set_color

• AH = $1B
• CX:BX = LCD Mono Shade LUT value

INT $12/AH=$1C - lcd_get_color

• AH = $1C

Return:

• DX:AX = LCD Mono Shade LUT value

INT $12/AH=$1D - lcd_set_segments

• AH = $1D
• BX = LCD Icon Control value

INT $12/AH=$1E - lcd_get_segments

• AH = $1E

Return:

• AX = LCD Icon Control value

INT $12/AH=$21 - screen_set_vram

• AH = $21
• AL = Screen (0, 1)
• BL = Internal RAM address, shifted right by 11

Note: This function is undocumented.

INT $12/AH=$22 - sprite_set_vram

• AH = $22
• BL = Internal RAM address, shifted right by 9

Note: This function is undocumented.