COUPLE OF QUESTIONS:
1.where within the Mach 3 file system can I locate and review the Default G Codes as they appear in the upper right of the menu screen?
2. have there been any updates to the Mach3 software in the last three to 5 months?
3.how can I manually edit Machine Coord under the Diagnostis menu/screen and
4. under the Offsets menu/screen how can I manually edit the Part offsets?

(;-) Thank You

1.  Do you want to access the Mode message line OR do you want to see the reference of what the gcodes do?  I don' think you can access the Mode line and you can see the Gcode references ON SCREEN by pressing the Gcode button lower left hand side of the main page(program Run)

2.  You need to look at the download page and read the updates section to see what and when things were done to the versions. That way you get fresh info.

3. You cannot edit the Machine coord base the only thing you can do to it is Reset it to zero based on your current position(not recommended)

4. You edit the table and tool offsets in the Tool table and the Fixture offset tables in CONFIG  OR through Gcode calls. You can also modify the CURRENT Fixture offset from the offsets page.

Hope that helps, (;-)TP

COUPLE OF QUESTIONS:
1.where within the Mach 3 file system can I locate and review the Default G Codes as they appear in the upper right of the menu screen?

Most are set with the way you have Mach configured, such as the CV /ExactStop IJ modes, Metric/Imperial etc

2. have there been any updates to the Mach3 software in the last three to 5 months?

Check the change log on the Mach download page.

3.how can I manually edit Machine Coord under the Diagnostis menu/screen and

Homing sets machine coords and is the only way it can be done, well there is another way to zero machine coords via VB but really homing is the way to do it.

4. under the Offsets menu/screen how can I manually edit the Part offsets?

Click in the DRO type what you want and hit the enter key on your keyboard.

Edit

Oh well too slow in typing I see