A simple character generator, see Text mode on Wikipedia. Both scan line and dot counter binary registers are divided to high and low parts. These high parts combined serve as a character index and are passed to the text buffer (character pointer table), those output is a code point. Code point, and low parts of scan line and dot counter are indices in 1-bit three-dimensional array (ROM or RAM), representing a monospace font. Its output is a text mode video signal. The 3-bit low parts of scan line and dot counter produces a 8×8 glyph matrix, and the 5-bit character row and column indices are typical for video architectures of the ZX Spectrum, Nintendo Entertainment System, Sega Master System, and Game Boy.
Own work
Incnis Mrsi, Damian Yerrick