case 580 powershift question

Hello all, newbie question here. I am in the process of buying my first real backhoe. went the farm tractor and add on hoe first and was not impressed. Finally found a 99 580 super l with a powershift trans. Looked at it this week, runs great, pretty tight, hoods a mess but that is the norm. Heres my problem, I cant find any info on the powershift trans. More specifically what the button on the forward /reverse lever does and when pressing the mode button on the display what that changes. i seam to scroll through 3 or 4 abbreviations. trying to figure out what those mean and if there are different modes or what they might be. Problem #2 is it has a hydro qc on the loader. I have no idea nor does the guy selling it know how that works. any info would be appreciated..... Pics to follow this week!!!!

Thanks in advance

case 580 powershift question