Returns the separator character used in the file path names by the operating system. On Windows machines, this character is '\'; in UNIX, it is '/'; in VMS, it is '.'.
macread(strcat("DSP", pathchar, "macros", S))
defines the macro DSPMACREAD to read in macro file, S, from the "macros" subdirectory of DSP.
PATHCHAR is helpful for setting up folders for menus and SPL functions.