Logic Board Assembly

A 5 MHz dot clock drives a 9-bit Horizontal dot Counter (S16, S17 and T17) and an 8-bit Vertical Line Counter (G17 and K16). The horizontal counter counts from 0 to 255 during active scan lines and 256 to 317 during the horizontal blanking time. When the horizontal counter reaches 317, it resets to zero. At the beginning of the horizontal blanking time (horizontal counter 256), it increments the vertical counter. The vertical counter counts from 0 to 239 during active vertical blanking time....