code: function doADC( value ) {
  		var t = A + value + flagC;
  			
  		flagV = !!((A ^ t) & (value ^ t) & 0x80) && 1;
  		flagN = !!( t & 0x80 );
  		flagC = ( t > 255 );
  		flagZ = !( t & 0xff );
  
  		writeA( t & 0xff );
  	}
docs: Actually performe add with carry.
  Useful, as SBC is also a modified add-with-carry.