Catatonic Rockwell AIM-65

[Mark Matlock]

Rick,
   I have a Rockwell AIM-65 and back in the day did a lot of laboratory data acquisition and other things with them. I interfaced one to an atomic absorption graphite furnace  to collect the readings and compute the parts per billion of various trace minerals in samples to translate 6 bit ticker tape code at 66.67 baud to 9600 baud ascii for a PDP-11/44. I did development on the AIM-65 and then transferred the code on EPROMs to Rockwell RM6500 single board cards usually. At home I made a ballistic chronometer with some aluminum foil and a resistor and my trusty AIM-65.

   The most interesting project was an instrument I designed to measure how stable a vegetable oil was to oxidation. The AIM-65 would test 16 samples using a wire wrapped relay board to sequence through the signals, an Intersil 7109 12 bit A/D chip, a conductivity circuit, 32 Kbytes of RAM to hold data for plotting and a small 4 inch wide Radio Shack Pen Plotter. We built about five of them to use within our company, but had requests from customers for the instruments. Eventually, we out licensed the patents to an external company and I rewrote the software to run on a IBM PC. Later I rewrote the software in LabVIEW and it still runs in many labs where vegetable oils are refined or used. The analytical method  for it is called the “Oil Stability Index” and I wrote the official method (AOCS Cd12b-92) that defines it. If you search for “Oil Stability Index” you’ll find it is widely used in the field. It is also sometimes called the Rancimat method after another automated instrument introduced later that works in the same way.

  When I do get my AIM-65 out to play, it often is catatonic at first. I’ve found that (at least for mine) it is related to the inexpensive IC sockets Rockwell used in it. Usually some Deoxit or tuner cleaner on the sockets and reseating some ROM chips is all that is needed to get it going. That said you certainly could have more complicated issues as well.

Best,
Mark