Homebrew PCBs

When creating a drill file (NC Excellon) in Protel it generates a file that
contains the tool numbers and the X & Y coordinates.  Unfortunately it does
not indicate if the holes are plated or not.

That information is in a separate file with the extension .DRR.  It is also
indicated in Gerber files with the .Legend directive.

 

The problem for PCB manufacturer is that the NC drill file needs to be
separated or used twice:

1: First pass all plated holes ae drilled, patterns are added, plated,
etched and so on.

2: Afterwards the panels are put back in the Excellon drill and the second
part of the drill file with unplated holes are drilled.

 

Some PCB houses request that two drill files be delivered, plated and
non-plated.

 

I am really surprised that there is not an option to include the
plated/unplated and drill size information in the common drill file or at
least I have not found it.  Similar to the apertures being included in a
Gerber header.  That brings my questions:

 

Is there a standard for including the info in a common NC file?

 

Is there software available to split the NC file?  I have bene doing it
manually and thinking about writing a little program but of course I would
be happier if I could find it and not have to spend time on that.

Thanks in advance,

Bertho