UM6845:
*Bits 7..6 define the skew (delay) of the CUDISP signal (00 = Non-skew ; 01 = One-character skew ; 10 = Two-character skew ; 11 = Non-output).*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.
UM6845R:
*Bits 7..2 are ignored.*Bits 1..0 define the interlace mode.
MC6845:
*Bits 7..2 are ignored.*Bits 1..0 define the interlace mode.
Pre-ASIC/ASIC:
*Bits 7..6 define the skew (delay) of the CUDISP signal.*Bits 5..4 define the skew (delay) of the DISPTMG signal.*Bits 3..2 are ignored.*Bits 1..0 define the interlace mode.