The situation: An old (more than 20 years) Epson LX-850 9-pin dot matrix printer, no parallel port on the new motherboard and so using a USB to parallel adapter cable
Here's what I did to get it working on Mageia 2:
1. Installed task-printing (to get the Epson drivers)
2. Commented the line blacklist usblp in /etc/modprobe.conf.d/blacklist-cups-common.conf
3. Made sure that the printer was switched on and "online" and then re-booted.
4. Confirmed that /dev/usb/lp0 now existed
5. Using MCC - Hardware - Printer set up the printer as a parallel printer on lpt0
6. Right-clicked on the printer's icon and selected Properties
7. Manually changed the Device URI to parallel:/dev/usb/lp0 and clicked on Apply.
I was then able to print a test page.
There may be some procedure that is simpler or more elegant, but this worked for me. It may be of use to someone else trying to get a USB to parallel adapter working with a very old printer.
Jim