use 5.014;
use Data::Dumper;

open my $inFH, q{<}, \ <<EOD or die $!;
N260G02X142.05Y649.62I77.33J58.34H2M25
N265M20
N270G45
N275G01X304.78Y608.8C45.91M25
N280M20
N285G46C0
N290G03X324.39Y638.4I-69.58J67.4H2M25
N295M20
N300G45
N305G01X180.04Y592.89C326.5M25
N310X279.77Y586.78C26.5
N315X195.39Y584.57C336.5
N320X228.31Y579.58C355.92
EOD

my @dataLines =
   map { { split m{(?x) (?<=[A-Z]) (?=[-\d]) | (?<=[-\d]) (?=[A-Z]) } } }
   map { chomp; $_ }
   <$inFH>;

close $inFH or die $!;

print Data::Dumper->Dumpxs( [ \ @dataLines ], [ qw{ *dataLines } ] );