Why would one want to dissable jiffydos? Why the switch? What kind of trouble can one Get into if one did not have a switch and left it on All the time, any examples? :) cheers guys, and Thank you... By the way I just successfully used one of my 28pin to 24pin boards... For my 1541 upgrade, I have a ton of LED's so I used their leads as pegs to plug into The 24 pin socket... the legs are thin flat and pretty rigid... :) the boards have a jumpter that allows you to select 2764 or 27128...