Watching YouTube it looked like left/right/open/close were pretty absolute commands, but that up and down varied (there are two steps in Gyromite but more than two for StackUp). So those two at least probably include some kind of distance or step command.   I don't have StackUp, but I took a look at Gyromite's signals via emulation, and these are the patterns I get. 0 is a black screen, 1 is a green screen (although any bright color will probably work, the color indexes used in Gyromite are $0