AGI/AGI256
AGI256
AGI256 is a hack on the original PC AGI interpreter v2.936 by Dark Minister. It adds 256-color background picture support to the AGI engine. It uses the default VGA palette.
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.
AGI256-2
AGI256-2 is an extension to AGI256 by Brian Provinciano. It adds 256-color view (i.e. sprite) support to AGI256.
Implementation details
As AGI256-2 is an extension to AGI256, all AGI256 implementation details apply here unless otherwise noted.
AGI256-2 modifies the sprite drawing routine to handle non-RLE-encoded raw 256-color data.