My favorite recovery (though it was not fun at the time) involved a headless machine that wasn't booting, and all I had available that would boot on the machine

My favorite recovery (though it was not fun at the time) involved a headless machine that wasn't booting, and all I had available that would boot on the machine was a floppy disk that ran a rescue shell. I modified the floppy to start linux with console=/dev/fd0, and so was able to type blind and then remove the floppy to read the output. After a few painful cycles of this, I noticed I could often guess at what was happening by listening to the write patterns of the floppy drive, and completed the rest of the recovery using essentially morse code.