Changes

On CRTCs 0/1/2, the condition VCC=R6 is considered immediately to activate the VBORDER. The only exception is for CRTC 1 with a value of 0, which triggers an immediate BORDER without the condition VCC=R6 being required.

On CRTCs 3/4, the condition VCC=R6 test is done tested only at new character line start. The update of R6 during the character line is therefore not considered.