Thanks guys
I managed to save the G code file onto a stick , carted it off to the workshop, and loaded g code directly into Mach 3 from the stick address (without copying elsewhere ) and all seemed to appear as required into the Mach 3 . So lookin good

Doesnt look like Cambam and Mach 3 speak the same dialect though !

So when I click start , the process begins and looks promising until it stops and I get I get an error message .
Says "Radius to end of arc differs from Radius to start (with block reference )
Block is G2 F800.0 X180.0 Z-0.0856 I-12.5717 J58.6681
No radius in there to trouble us , is there ????

And if i go to edit the .txt file come up with pages totally delineated load of code . Not a list , just pages of consecutive text, so finding the offending block to edit is nigh on impossible.