I'm looking for a decent G-Code tutorial.  Preferably one for Mach 3.  There are a couple projects I want to do that I think it would just be easier to write the raw g-code than to draw the picture in a CAD program, run it through the CAM stuff I can afford and then go back and tweak it so it will work.  I was just going to write it line by line, but then I ran across a reference to routines or subroutines that seemed to indicate you could do reiterative work with Mach 3 compatible g-code. 

I do not mind buying a book.  I'm not looking for a freebie or a handout. 

Specifically it seems to wasteful and confusing to repeat the same code over and over to cut a pocket.  It seems it would be a lot easier to increment Z and go back to the same code instead. 

You can use the wizards for a lot of simple stuff. There is also a wizard that you can use for repeating a shape and incrementing down on the Z at a preset step. I have not used it in a long time but if I remember correctly you put the full Z depth in your code and then go to the wizard and decide what step you want to go down on the Z.
 As for books then probably best to read up on Fanuc as the next version of Mach is being made to follow Fanuc very closely.
Hood

I have an idea for you. Use CopyCat, there is a manual,and it rather easy to use. Just put a tootpick in the chuck instead of using a camera. Make a sketch of something and then trace it out with CopyCat. The Gcode will be generated on the fly, you can learn a lot.

I would recomend the books by Peter Smid. Lots of reading in there!

If you can do CAD, then Lazycam Mill can be used to generate code, and very quickly, a pocket or  profile, check out the manual for it.

Some of the wizards are very good, Andy's Circle Routines are very nice and easy to use.

BTW, for ARC's ( done primarily  for the lathe ) you may want to take a look at ARC Motion in the Members Docs.

Just some suggestions,
RICH

I attended the MACH 3 seminar @ Cabin Fever in January . Brian is working on Standardizing the program and is using the Peter Scmidt Bood as a guide and he carries a copy with him . I picked up a copy for myself
CNC Programming Handbook Peter Smid isbn 978-083113347-4
Tin

There are two books by Smid ,and although i don't have the one Tin refers to, I have read parts of it and
think it is easier.
RICH

BOb: yo can preview Peter Smid's books here.
http://books.google.com/books?q=peter+Smid&btnG=Search+Books
Tin