Changes
CRTC
,/* Signal delay */
On CRTCs 3/4, the delay is identical for the HSYNC signal. While on CRTCs 0/1/2, there is no delay for HSYNC.
So on CRTCs 3/4, HSYNC occurs 1µs later than on CRTCs 0/1/2. Interrupts being dependent on HSYNC, this is a serious source of incompatibility.
==== Discolouration effect ====