We have a Haas TL-1 lathe in our shop .
If I make a program in Mastercam , or any other CAM software, which
way should it be drawn. The way it looks in the machine(the front side of the part), or like our other machines, the back side of the part.
Do it the way you do for any other CNC machine where the tools are at the back. For writing programs just treat the TL as a normal CNC machine.
Really, 'front or back' does not matter, the reference point for the X axis is the spindle centerline; X movement in a negative direction moves toward the spindle centerline. positive moves away. It does not matter whether the tool is in front, behind, above or below.
An open mind is a virtue...so long as all the common sense has not leaked out.