BGMaps are used for displaying large, static images on the VB Screen. Each BGMap, known as a "segment", is composed of Chars from Character Attribute Memory. A segment is a 64×64-character (512×512 pixel) image consisting of 4096 8×8 pixel characters. These characters are laid out in left-to-right, top-to-bottom order.

Table 2.3 - BGMap: Arrangement of cells within a segment; 1 Segment = 4096 Cells

While it is possible to move the entire BGMap relative to the display, it is not possible to move the individual character cells relative to one another. The H parameter of the World in which a BGMap is displayed cannot be less than 7 (meaning 8 pixels high), but can be increased in increments of 1.

There is enough RAM to store up to 14 BGMap segments. The region of memory where BGMaps are stored, which ranges from 0x0002_0000 to 0x0003_C000, inclusive, is shared with the parameter table(s), if any. Parameter tables define the parameters for H-Bias and Affine transformation effects. Any space not used to store BGMap data is free to be used for H-Bias and/or Affine parameters, but the BGMaps must always be aligned to 8192 byte boundaries, starting at 0x0002_0000.

Each cell of a BGMap segment is a 16-bit entry consisting of a 2-bit palette index, two 1-bit mirroring flags, a reserved placeholder bit, and an 11-bit index into character RAM.

1 segment: 16 bits * 4096 (0×1000) = 8192 bytes (0×2000 Bytes).

Table 2.4 - BGMap Cell format