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1, 2, 4, and 8 Bits Per Pixel

With pixel formats 1 byte long or less, no pixel transformation is required, because the bridge's address-invariant byte swapping does not affect data below the byte level. However, it is important to recognize that PCI-based Power Macintosh computers assume that pixels are packed into bytes in left-to-right order. For example, in 1-bit mode the most significant bit of a byte is the leftmost visible pixel on the screen. This is consistent with existing VGA pixel formats.

Figure B-1 shows 1-bit-per-pixel mode. The 2-bit, 4-bit, and 8-bit cases are similar.

Figure B-1    1-bit-per-pixel formats