dviconcat − concatenate DVI files
dviconcat [ −m magnification ] [ −o outfile ] list of files
Dviconcat concatenates the named files (or standard input, if no file names are given) onto the standard output or the given outfile, creating a new DVI file usable by any of the TeX conversion programs, or even by dviconcat itself.
The magnification of the output file is the same as that of the first input file unless the −m option is given. When dviconcat changes the magnification of any input file, it prints a warning to this effect.
Chris Torek, University of Maryland
MC-TeX User’s Guide
The program should be called dvicat, but that name was taken (for the driver for the C/A/T typesetter).