otto - DOS 6.22 is an old operating system for a PC, before win3.1 or win95.
A Serial port is a 9 pin D shaped connector that is on most older laptops and computers.
This is the same software and it comes with a cable . . .
http://cgi.ebay.com/ebaymotors/FICHT...QQcmdZViewItem
I almost forgot you'll want a service manual too . . .
http://cgi.ebay.com/ebaymotors/150-1...QQcmdZViewItem
One last comment . . . The mid sections/lowerunits of these motors is the same as the Carb versions, so if for some reason these FICHT's don't work out . . . you can yank the powerheads off, hawk the parts on ebay, and replace them with dressed Carb powerheads.