Awhile back I saw some USB-to-serial adapters which were extremely slick. Imagine the whole package in the same form-factor as the DB-9 (serial) pin header. That’s right! The whole adapter fits in the same footprint as the serial port connector which your device uses.
Now instead of a USB-to-serial cable connected to your device, you can just connect directly to a USB port – no need for that silly adapter cable! Just solder one of these modules in place of the existing passive serial-connector and you have yourself what has effectively become a USB device! What a great way to modernize a legacy piece of equipment.
You can purchase these adapters for about $15 from Digikey.
Update: I purchased a couple of these units and they are fantastic!! I installed one in a DSP-232+