Dedication: Since this whole series follows my history with computers in the Bay Area, I want to dedicate the final cache to a true pioneer I had the honor of working with, Betty Holberton. She was one of the first 6 programmers of digital computers ever, all women. http://en.wikipedia.org/wiki/Betty_Holberton The CDC Cyber 180 Series represented Control Data's final break with the 60-bit words and 6-bit characters that were used by all models starting with the CDC 6600. The new hardware used 64-bit words and 8-bit characters. However, the hardware models were ready well before the NOS/VE operating system, new compilers,etc. In order to achieve a graceful transition, the machines had an alternate microcode that could run all of the old 60-bit code. Therefore, they were originally sold as the Cyber 170/800 series and appeared to be just another hardware technology rev of the existing line. When the new 64-bit mode operating system and software was ready, all that had to be done was announce it and let existing customers know they already had hardware that could run the new mode at the same time as the old mode. This provided a way for customers to move to the new architecture while still running their old software.
There were clues that observant customers might notice like 16-bit wide sets of switches in the Deadstart Panel, hardware switches that loaded the initial instructions to boot the hardware.
By the time CDC moved facilities from the Orleans Drive location to Clyde Avenue, the starting point of of this multi-cache, little software development for any of the hardware was going on. The company had morphed its remaining software talent into a consulting style operation and some web development work. The company had been bought by Syntegra, a division of British Telecom, and lived out it's final days in the Bay Area at this location.
The large green utility box near the corner of the 520 Clyde Avenue building has a visible number of the form C-rstu
A = r + s
B = s + s
C = s
D = t
E = u - s
F = s
The sum of the digits A,B,C,D,E, and F should be 24. The final stage is less than 1/2 mile away.
The cache is located at N 37° 23.ABC W 122° 03.DEF
As always, try to put things back exactly as you found them so the next seeker can have as much of a challenge as you did.
Note: 4/21/2014 Recent work added a big set of external piping on the side of the walkway.The cache is not hidden in the piping since this is a new addition to the area and the hide style has not changed.
You can validate your puzzle solution with certitude.