Trying to learn about stepper motors so I assembled the l297 l298 combo as shown in the datasheets. I can turn the assembly on and off with the enable pin. Ground it and all the driver pins go to low. Set the enable pin high 5V and I get what appears to be the home state. At the l298 output 1 is low 2 is high 3 is low and 4 is high. I have tried just about every combination of the other pins but what I have read those really shouldn't make much difference for the basic operation. I am using the 7805 for the l297 circuit it maintains 5 volts at all times. I am using a 4.7nf capacitor for the chopper but again that shouldn't matter for the basic operation. The clock input is from a 555 timer circuit. I also tried pulling pin 18 low with a resistor but still nothing but the single state. Perhaps I just got a bad chip but since the oscillator is working, and pin 10 is working it seems I might be doing something wrong. Also if I pull pin 20 to ground it doesn't appear to affect the state of pin 3. From what I can gather pin 3 is an open collector so placing a pull up resistor and an LED on pin 3 I should get a light when the chip is in Home state. I should be able to force this by making pin 20 low but that does not work. Bad chip or am I missing something.