CRTC 2 is the exception. R4, R5, R6, R7 do not need to be reprogrammed as it considers each character line to be a double character line.
==== Interlace Adjustment adjustment line ====
On all CRTCs, in both interlace modes, an additional line (the 625th line) is added automatically by the CRTC at the end of the even field. This line is added after the lines of the vertical adjustment mode.