[experimenter]

I found a way to remedy by adding an offset to the sync line under video_gen.cpp

if (mode) {
display.start_render = _PAL_LINE_MID – ((display.vres * (display.vscale_const+1))/2)+40; // added the “40” to shift all lines lower.
display.output_delay = _PAL_CYCLES_OUTPUT_START;
display.vsync_end = _PAL_LINE_STOP_VSYNC;
display.lines_frame = _PAL_LINE_FRAME;
ICR1 = _PAL_CYCLES_SCANLINE;
OCR1A = _CYCLES_HORZ_SYNC;
}

Another question michael. I would like to know which variable tracks how many sync lines where read before int0 is triggered with the vsync signal. It seems that “display.scanLine” only ramps up to 7 before getting the interrupt signal which I dont understand but it also means that this is not the correct line counter variable. Basically I would like to write a script that would distinguish PAL from NTSC on the fly via tracking how many lines came in before the vsync trigger.

Thanks again for the help.

[Author]

Posts