Controller Software Suggestions Please

Well after using my Sherline converted CNC milling machine for about 5
months, I am now at a point where I am seeing limitations in the software
used to control the stepper motors. I have Camtronics 2A controller board
and I am driving it via TurboCNC. The only thing that I use the CNC for is
to do detailed line engravings on titanium rings. Since I have a rotary
table controlled as one of my axes, I can only use G01 linear movement
commands. The rotary table is set up in degrees and the arc commands only
work on linear axes. Because of the relatively small line segments pieced
together in order to make a smooth curve, I am finding that the endmill is
not leaving a nice enough finish on the bottom of the carving. i am getting
some striations due to the starting and stopping between line segments. I
believe that controller software that does continuous contouring will
alleviate this problem. Is that correct? If so, what is an inexpensive yet
effective software to use on a DOS computer?

If I slow down the motors significantly then I get rid of the machining
marks, but it is taking too long to cut the patterns.

Thank you for any and all of your suggestions.

Daniel J. Statman, Statman Designs
www.statmandesigns.com