MFM drives do NOT like RLL encoding

[cr1901]

My embarrassment gets even better...

I tried all my remaining MFM drives on the two controllers I had, and they all failed. Thinking something was up, I took out the main hard drive (the original CMI drive- still works Mike ...) from my PC/AT and installed a number of the tested hard drives in... they worked just fine.

... turns out, both remaining controllers I had were RLL controllers... I don't have any MFM drives except for the dying Kalok Octagon.