If the original machine boots, there are many
possibilities.  I once
 did a linkup with a system with NO serial or parallel ports (and an
 utterly incompatible with anything floppy setup) by bit banging an LED
 on the console and picking the bits up with a phototransistor connected
 to some parallel port pins. 
Chuck,
I hate to think how long it would take to transfer a 400MB drive using that method... Of
course if the data is valuable enough...