A type of file format commonly used for gaphics and character sets.
The content of a chr file is multiple lines of bit strings, the position of these bit strings represent a pixel in an 8x8 tile (totaling 128 bits) going in a row-column order The. The color of the pixel is irrelevant because it's chosen through the code by the programmer with an attribute table, so it's the bit combination that is significant and there is no storage of color values. "Colors" the bit represents is the pixels level of brightness.
Ex 1: 0000 0000 003c 6642 4266 3c00 0000 0000
Ex 2: 0x00, 0x3c, 0x42, 0x40, 0x40, 0x42, 0x3c, 0x00
An array of hex, like the one in the first example, is converted to a C bit array, where each bit is an integer constant in base 16.