I  had the task on Implementation of a calibration station for the Trillium VLSI tester.
This was I task that I got when I first got to Intel the factory had invested in a custom
built test rack and test equipment but it lay dormant mostly due to the fact that there
were major risks in doing in house calibration of the stanards that the tester used.

I wrote a visual basic program that tracked the calibration data of the boards . I wrote a
white paper that showed that the data from the boards did not change from calibration
to calibration enough to cause a yield problem.

 I  opperated did the calibration for over Ten years  and saved $30000 per year in calibration
fees if the boards were sent to the manufacturer for cal

The Amux board was the had all the refrence resistors and voltages on it that got measured each 6 months and
entered into the tester.I compair the New Data with the Last Cal data and wanted to see a small change in values 
(1/10 of the window pass)

The tester used TDR to measure  the distance to the test head in calibration there were standard coils on the Tref boards
that I measured twice a year. I compair the New Data with the Last Cal data and wanted to see a small change in values 
(1/10 of the window pass)

The Values +1 +2 are with a repect to the refrence coil.

Tcon board was the main timming board I measured the frequency on  the board once a year.
the board was the main timming clock for the tester this changed from 200mhz downto 170Mhz
depending on the test Period

The last part of the program Tracking of all Digital boards by serial numbers via ftp to the testers and getting the

init_tester output 

The program checked to see if boards moved postion in the Tester.
The program also tracked boards that were removed from the Testers.