I have come across some custom DIP resistor networks in HP machines where it's not just isolated resistors or resistors from the pins to a common pin (the common standard configurations). With those, simple pin-pin resistance measurements are not enough ( I forget if it's enough in theory, but in practice if the resistors are wildly different values you won't do it). I seem to remember working out a method where you (a) measure resistance from each pin to all other pins strapped and (b) make a potential divider using one pin as the input, another as the output and all others strapped as the common. Repeat for all combinations of pins. Here, I think is how it works out. Suppose in (b) you apply the input to pin x and take the output from pin y. Suppose that there is a resistor r between x and y, and the parallel combination of all other resistors on pin Y has resistance R. Then the division ratio is clearly R/(r+R) Now think of (a) using pin y (the pin that was the output of the potential divider). Resistor (r) is now included in the parallel combination, so the resistance from pin y to all others strapped is (R.r)/(R+r). Dividing one by the other will give you the value of r. Repeating for all pin combinations will give you the resistor between each pair of pins -tony

Resistor networks.. AB should have been the tip-off. Thanks for the help, everyone. But I can't say that I have any use for the things.. anyone need a few? Would be helpful if we had a catalog or some kind of literature.. On Sun, Jan 18, 2015 at 2:11 PM, Chuck Guzis <cclist at sydex.com> wrote: