SEGA SATURN DEVELOPER'S MANUAL

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Gouraud shading table area
This is an area that stores a Gouraud shading table of 1 entry and 8 bytes.
The same size exists in areas 0 and 1.
Color lookup table area
This area stores a color lookup table of 32 bytes per entry, and is managed with numbers starting from 0. Area
Commonly referenced from 0 and 1.
Block pool area
Character data and subroutine commands (subroutine commands) in areas commonly referenced from command areas 0 and 1
command is not currently supported). Character data is managed with numbers from 0.
The allocation of character data, etc. to this area is dynamically acquired / released in block units (32 bytes).

[Allocation size of each area]

The size of each area is assigned as follows. One block is 32 bytes.

Area name	Number of blocks
VRAM area reference switch command	1
System command area	4 × 2
User command area	COMMAND_MAX × 2
Gouraud shading table area	(GOUR_TBL_MAX + 3) / 4 × 2
Color Lookup Table Area	LOOKUP_TBL_MAX
Block pool area	All remaining blocks

COMMANND_MAX: Maximum number of commands

GOUR_TBL_MAX: Maximum Gouraud shading table count

LOOKUP_TBL_MAX: Maximum number of lookup tables

These values are defined by the VDP1 extended processing work area definition macro described later.

[Block allocation algorithm in block pool area]

● In case of acquisition
Search the free continuous block area that satisfies the acquisition request block size, and allocate the smallest area.

● In case of release
If there is an adjacent free block after releasing the specified block area, the continuous free blocks are measured and large
Group into empty blocks.

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