I used the badflash 2-connector cable and it works fine.
I also got the characters you saw (or at least some characters). Every time I hit a key on the keyboard, I got a new line with the same characters.
It turned out that the problem was...
I forgot to set the drive partition to be active. I put the drive back in my desktop machine as Drive C and used fdisk from a floppy to take care of this. Worked beautifully after that.
I later cut the cable down to 4 or 5 inches. It's still too long, though.