@Substring ok. i think i approximately understand the logic behind it. now i got a perfect output. a centered picture and the graphic quality is absolutely beautiful pixel by pixel.
One problem is, that Marvel vs Capcom for example is nearly a widescreen game. With 320x240 i can't get the full screen because the game got a resolution of 384x224pixels.
I've found a solution for that here but where i have to put the runcommand-onstart
and runcommand-onend scripts when i switch to retroarch? simply in the script folder?
And last but not least my config.txt if anybody needs. the timings are perfect for a Sony Trinitron KV-21X5D (of course you have to make the correct settings in retroarch. so no scaling, turn off pixel perfect, custom aspect ratio, setting offset etc.)
#uncomment if you get no picture on HDMI for a default "safe" mode
#uncomment to force a specific HDMI mode (this will force VGA)
#comment to get jack audio
#force hdmi while the tv can take time before sending the signal on the hdmi output
#uncomment for composite PAL
#uncomment for lirc-rpi
#if you plug your tv at the same time as your rpi and that the rpi switches from the hdmi or give a low resolution because tv had no enough time to initialize it
#uncomment if you don't want the rainbow at startup
#NOOBS Auto-generated Settings:
hdmi_timings=320 1 10 30 47 240 1 4 3 15 0 0 0 60 0 6400000 1