Changes
CRTC
,/* HSYNC */
The HSYNC width value is interpreted differently between CRTCs. On CRTCs 0/1, if 0 is programmed then no HSYNC is generated (and therefore, no interrupts). On CRTCs 2/3/4, if 0 is programmed then this gives an HSYNC width of 16.
==== Contiguous HSYNCs ====
On CRTC 0, two HSYNCs cannot be contiguous. They are always separated by at least 1 CRTC character.
On CRTCs 1/2/3/4, HSYNCs can be contiguous.
==== Signal delay ====