1. SECAM is a little weird. It takes the PAL software, but
the console color/black & white switch is hardwired as
black & white. Therefore, it reads the PAL black & white
tables in software and assigns a fixed color to each lum of
black & white according to the following table:
There is a trap here: the manual is the same for NTSC,
PAL, & SECAM. This means that the descriptions for black &
white must jive between NTSC & PAL. If you make major
changes to PAL black & white to achieve good SECAM color,
NTSC black & white must be made similar.
2. PAL sounds work fine on SECAM with one exception: when a
sound is to be turned off, it must be one by setting
AUDV0/AUDV1 to 0, not by setting AUDC0/AUDC1 to 0.
Otherwise, you get an obnoxious background sound.