Now that my RX02 floppy drive is working I decided to try and figure out what is wrong with my RL02 drive. I began by checking the sector transducer and sector timing test points. As you can see, they are quite nicely aligned:
I moved on to checking the output from the heads on the R/W module.
Comparing the left to the right you can see that the servo burst S2 is offset in the wrong direction, which suggests it is reading from the wrong side of the platter. Weird - so I checked the connections for the heads. In an RL drive, there are two heads - one for the top (facing down, the
down head) side of the platter and one for the bottom (facing up, the
up head) side. For some reason,
up was connected to the
down header, and
down was connected to the
Without thinking about the consequences I switched the connections and loaded a pack. Unfortunately this did not end well. I heard a horrible sound and hit the load button as quickly as I could to unload the heads. Inspecting the pack I can now see a thin black ring, which definitely was not there when I cleaned the pack.
It seems to me that the heads being mixed up may be the source of my RL02 problems. I'm not sure why switching the connections to make them correct would have caused an issue though. I am very sad about this. I have emailed classiccmp list to see if anyone has any idea of what happened.