I picked a big stack of HP150 single sided software
disks today, most of
which I didn't have.
Sidewinder Ver. 2.1 (no idea what this is?)
There have been a number of programs that use the graphics mode of a
dot-matrix printer to print pages sideways (you might say in landscape
mode). One of those programs was even _called_ Sideways. They were usually
aimed at spreadsheet users, because spreadsheets are much wider than they
are tall. Your disk could be one of these programs.
-- Derek