Changes
CRTC
,/* HSYNC and VSYNC */
CRTCs 1 and 2 have a fixed VSYNC width value of 16. VSYNC width can be configured with Register 3 on CRTCs 0, 3 and 4.
The bit 0 of port B of the PPI changes to 1 as soon as the VSYNC signal is produced by the CRTC.
== The 6845 Registers ==
