Hello, all: I decided to play with my 11/34a over the holiday, and discovered that one of my heretofore working RK05 drives has developed a chatter in the linear positioner. Here's what happens: the drive goes OnCyl with no problem, but on the first acccess, the OnCyl light blinks, and I get a device error returned to RT-11. I opened the case and watched the servo during this process and it seems to move in and out by one cylinder during this condition. So, I figured that there may be dirt on the positioner optics. I used compressed air to blow it off, which had no effect. Any clues? [ Rich Cini/WUGNET [ ClubWin!/CW7 [ MCP Windows 95/Windows Networking [ Collector of "classic" computers [ http://highgate.comm.sfu.ca/~rcini/classiccmp/ [ http://highgate.comm.sfu.ca/~rcini/pdp11/ <================ reply separator =================>