Serial numbers on AS/400s
The Serial number for an AS/400 server is a unique number. It is located on the front of the server and can be accessed from within the operating system using system value QSRLNBR.
Historically, the first two characters of the serial number have determined the location of manufacture, though this may not always be the case
- 06 - unknown location, for blade servers running i5/OS or China
- 14 - Denmark
- 10 - United States
- 44 - Europe
- 65 - Asia or Ireland
These unique numbers were also stamped on the machines themselves, but were not generally accessible from programming or visible on system displays.
Industry magazines released source code for RPG assembler subroutines which could read the serial number from IBM System/36s. These were published circa 1991, with names like SUBR## and SUBRSN. An EXIT/RLABL call from RPG retrieved the serial number into a 6-position field. There was no corresponding open source that would function with a System/34.
The serial number is one basis for enforcing a software license using a mathematical routine that converts an encoded text into a known constant. When installed on a new computer, a thusly-protected application no longer functions correctly because the serial number does not match.