Hi Peter,
Your change to the M23 position in the generated code is good and makes the editing easier - the M10P1/M11P1 commands I use are specific to Mach3 (
http://hobbycncart.com/publ/cikkek/mach3_temaju_cikkek/switching_a_laser_under_mach_control/8-1-0-29 )
I had to remove an M00 (not quite sure why it is there) and add the % character to the end of file and (because I am using a laser) remove the dwell commands but the editing is quick and easy to do and your code works extremely well.
Mach3 will run just fine on your 64 bit machine it is just the parallel port drivers which don’t work.
You are welcome to use my posted pictures (if I had known, I would have used a clean piece of stock).

Tweakie.