Michael,
here is a section of one of my tape files.
(CUTTER_DIAM : 0.187500)
G91G28Z0.
G90G49
M01
T8
M6
S8900M3
If this is what you are looking for I would need to see the post to see why it isn't outputting like this. It's a pretty straight forward post file that I am using.
Steve