I don't know why it's so hard for people to download and read a manual
ShowDesigner Manual
But, as far as firmware, I looked at the binary, and wow, not human readable. Of course, you can still use Terminal, but if you lack a serial port on your PC, you're going to need a USB to serial adaptor cable and then a null model cable or adaptor to make the rest work.
Of course, I also don't see the Show Designer software available via the ADJ web site but I'm also not going to make a major effort right now either.
The unit has been discontinued. I'm sure someone has to have the software laying around.