1kohm_to_gnd: connected to ground via an 1kOhm resistor,
6kohm_to_gnd: connected to ground via a 6kOhm resistor,
20kohm_to_gnd: connected to ground via a 20kOhm resistor,
+ 90kohm_to_gnd: connected to ground via a 90kOhm resistor,
100kohm_to_gnd: connected to ground via an 100kOhm resistor,
125kohm_to_gnd: connected to ground via an 125kOhm resistor,
500kohm_to_gnd: connected to ground via a 500kOhm resistor,