The CRT A1 card controls the display that will be shown on the CRT. The board run on a 8085 microprocessor. It transmits the red, blue, green, and sync signals to the CRT monitor. The board has two LEDs. Board contains no jumpers.

 

LEDs       Purpose:

 DS1      Is dimly lit when outputting data. 

DS2      Normally lit, shows CPU is running.