Stepper controller to manually input a specific degree

[m_c]

I don't really see much point in using the above methods when you can just use a computer you found in the skip, connect the parallel port a cheap stepper driver and run it on mach3 / linuxcnc. You don't even need a breakout board if you use an opto isolated driver (e.g. m542) and the parallel port is old enough to output 5V.

Convenience. With a standalone controller, you just need to plug it in and go, with none of the faff involved with setting up a computer. Then when you're finished, you can unplug it, put it back on the shelf/in the drawer and forget about it.