These have been take out of military test gear, they are built on ceramic material and the resistors are laser trimmed to value. Two pins are for power to the logic which is 5 to 7 volts. Two pins are for the resistance output, And 10 pins are for selecting resistance. This circuit accepts 10 bit binary code to determine the output resistance. Taking the individual pins high one at the time gives the following resistance out put:
As can be seen the values go up by doubling the previous value.
I used a fluke multimeter to measure the resistance, please bare in mind that they probably will be different values measured with other multimeter, but they wont be that much out, the resistors are in 0.1% tolerance.
