The standard BobTach is manually operated, you have to get out of the seat and use the levers to disconnect a attachment or bucket, then sit back down, move to what ever you want to attach, engage the attachment plate, lift the attachment, then get out of the seat again and use the levers to lock the wedges in.
On a power BobTach you can do it all from the seat and is a option available on later models machines. I sure Bobcat would get big bucks to add this option later because it would require a different BobTach, running of hydraulic lines, installing the valve and electrical.
By looking at the Bobcat historical specs it looks like the first year a power BobTach was available is 2003.
http://www.bobcat.com/historical_specs