Changes
CRTC
,/* UM6845R and R12/R13 */
Just like other CRTCs when RC==(R9-1), the current MA is captured for the next char-line.
In demos to make a display compatible with all CRTCs , program R12/R13 when VCC!=0. This will then take effect at the next frame start.
=== UM6845R status register ===
