*Bits 5..4 define the skew (delay) of the DISPTMG signal (00 = Non-skew ; 01 = One-character skew ; 10 = Two-character skew ; 11 = Non-output).
*Bits 3..2 are ignored.
*Bits 1..0 define the interlace mode (00 = No interlaceInterlace; 01 = Interlace Sync; 10 = No Interlace; 11 = Interlace Sync and Video).
UM6845R: