g77 issues

[Paul Koning]

I'm not sure if these qualify as bugs but they are problems I ran into
trying to use g77 on what was a working Fortran program that operated
correctly with older (e.g., DEC Ultrix) f77 compilers.

1. Attempts to open unit 5 or 6 fail.  The program tried to offer the
option to output to a file by opening that file on unit 6.  I had to
change all the I/O to use a variable unit number instead.

2. In data file parsing, the code was looking for tab characters by
using the quoted string '	' (that's '\t').  That didn't work, I
don't know what the compiler did to it.  Comparing with ACHAR(9) does
work.

Are these ANSI mandated problems, or things that were always wrong and
just happened to be permitted, or g77 bugs?

	paul