Character Generator - Zenith Z-100 Reference Manual

Page 7.8
Video Graphics Programming

Character Generator

The ROM character generator on the video card, when in text mode, generates
software-selectable characters from dot p
configurations are provided: 7 x 7 double-dot width, 5 x 7 single-dot width,
and underlined versions of either of these character sets. You may install provided
hardware jumpers to enable either of the character types at powerup, and/or
use 8088 I/O OUT commands to program select your choice.
Timing Generator
The timing generator creates the timing signals for the 6845 CRT controller and
the dynamic display memory. It also handles traffic control between the CPU
and CRT controller for display buffer access.
Video Output
The video output circuitry routes the video information to the proper output con-
nector. It sends color dots to the RGB connector and generates levels of gray
for the monochrome output.
atterns stored in the ROM. Four character