John,
Thanks for that but after doing a bit of searching earlier on the same site I determined it was a System 4 but with only three cards fitted.
I now have about 5 copies of the various iterations of that System4 book.

Many thanks anyway.

Will have some more question is a fresh thread as this machine a Boxford 160 has a toolchanger fitted and it's been roughly converted to Mach3 [ one axis moves ] but it's lacking the tool changer macro.

However I need to do some homework for myself first and then if still stuck, start a new thead.