I have TurboCad Deluxe 10 running under OS X 10.3.6 on one Mac. When I use the scaling command on an object, I always get uniform scaling. That has always been what I wanted, so I haven't given it any thought.
But on another Mac running OS X 10.14.6, I always get differential scaling.
I am unable to see any way to get uniform scaling on the second Mac. The manual (p 255) says: "The user interface provides two types of scaling: uniform and differential" and "The Uniform Scale tool will scale using input from mouse clicks or a scale value entered in the Data Entry Window". Later it says "The Differential Scale tool will expand or shrink a curve, surface or solid, in a non-uniform manner with respect to the x, y or z axis."
I do not see anywhere to choose uniform versus differential scaling. My interface shows only one scaling tool, and the Modify>Transform menu command lists only shows one Scale item. Similarly, the image of the icons at the top of the manual page describing Transformations shows only one object for Scaling. I've tried various modifier keys when selecting these commands and tools, but these make no difference.
How to I choose between uniform and differential scaling? I can see a similar option associated with the Gripper, where I can turn "uniform" on and off. That works as expected but has no effect on the behaviour of the Scale command.