AGI/AGI256/Implementation Details

In the original PC AGI interpreter v2.936 the engine holds the color and priority/control line information for each pixel in a 160x200 byte buffer. The color data for each pixel is held in the byte's lower 4 bits and the priority/control line data is held in the upper 4 bits.

AGI256 extends this 160x200 byte buffer to a 320x200 byte buffer so that the 256-color data is held in the right 160x200 half of the buffer and the original style 16-color and priority/control line information is held in the left 160x200 half of the buffer.