yes it is right with either the switch or jumper >high side< not grounf side.,
555 is a 1 shot timer,which need's to be reset every xx depending on it's r/c constant.,and for wdt decorder chip's,gate's/nor/_or/exulsive or/nor/decade counter's,it run's the gamment,it all depend's on the board and complexity of the down stream circuit's and there demand's..,some may have different timming issuie's
or different _ce/_cw/clk/reset/_reset,and most of all there call in the micro proseser
"register stack",which by nature is rom controlled >game rom<.
so basicly as i have been trying to explain to u
when the wdt fire's u have a down stream problem,this is where u need to know what line's
should be doing at >xx< and what they are not to be doing,the wdt is a good starting point,as it will by it's control line's tell u where u need to be to repair the game board in question
ed