🚀 go-pugleaf

I've got my asbestos underwaer on in case I am wrong and the flames are hot!

Some of the old controller cards for the IBM hard drives had no jumpers
or switches on them and would only work with 10 meg drives. If it has jumpers
or switches then you can probably reconfigure it for 20 meg. There are usually
three sets of jumpers if there are any. one is for the memory address of the
ROM on the controller and this affects whether it is hard controller 1 or 2.
There is another set that controls the port address of the port used to control
the card. The third set is usually a set of 4 jumpers that control the
type of drive attached to the controller. (this is all from a limited 
experience with a couple of the old slugs) If you can do a low level format
using your diagnostics (not the format command...) then you can try the
sixteen possible combinations of the four jumpers until you end up with
the right one maybe! The easiest approach is to find doc on your card. Its not
hard usually to go to a few shops and find someone with the manual for
your controller card