It has been a while sence I have used one of these plc's. Although you could get software for programming these. A keypad was also available that would snap on top of the power supply/plc on the right side of the rack. I remembering programming these with the keypad, once you got the hang of it, it wasn't so bad. I also believe that the GE Series One, is the same as the Texas Instruments 305. Anyway, at one factory I worked at, we were able to inter-exchange the keypad and I/O cards between these 2 different brand of plc's. So, if you are searching around for info on your Series One, try searching for info on the TI 305.