The Tandem port is only minimally supported. The port's contributor no longer has access to a Tandem system.
The Tandem port was done on a Cyclone machine running D20. The port is pretty clean and all facilities seem to work except for the I/O piping facilities (see Getline/Pipe, Getline/Variable/Pipe, and Redirection), which is just too foreign a concept for Tandem.
To build a Tandem executable from source, download all of the files so that the file names on the Tandem box conform to the restrictions of D20. For example, array.c becomes ARRAYC, and awk.h becomes AWKH. The totally Tandem-specific files are in the tandem “subvolume” (unsupported/tandem in the gawk distribution) and should be copied to the main source directory before building gawk.
The file compit can then be used to compile and bind an executable. Alas, there is no configure or make.
Usage is the same as for Unix, except that D20 requires all `{' and
`}' characters to be escaped with `~' on the command line
(but not in script files). Also, the standard Tandem syntax for
`/in filename,out filename/' must be used instead of the usual
Unix `<' and `>' for file redirection. (Redirection options
on getline, print etc., are supported.)
The `-mr val' option (see Options) has been “stolen” to enable Tandem users to process fixed-length records with no “end-of-line” character. That is, `-mr 74' tells gawk to read the input file as fixed 74-byte records.