Another kick at the can:
void setup(){ /*123456789 123456789 123456789 123456789 123*/
String newRow="\n|________________________________________";
String scrSiz="\n|\n|\n|\n|\n|\n|\n|\n|\n|\t";
Serial.begin(115200);
// this baudrate should not have flicker but it does as seen when
// the persistence of vision threshold is insufficiently exceeded
// 115200 baud should display ~10000 cps or a char every 0.1 msec
// each 'for' loop iteration 'should' print 65 chars. in < 7 msec
// Serial.print() artifact inefficiencies are the flicker culprit
// unfortunately '\r' does not render in the IDE's Serial Monitor
Serial.print( scrSiz+"\n|_____ size screen vertically to fit _____" );
for(int i=0;i<30;i++){
delay(1000);
Serial.print((String)scrSiz +i +"\t" + (10*i) +newRow);}
}
void loop(){}