Epson LQ-300+

[Colin Dyson]

I haven't used Cups before. I'm planning printing through a network print server to a parallel Epson and also from another machine directly to a USB Epson LQ-300+II which I think is fundamentally the same printer apart from the port difference.
I've looked at the Administration page and the Epson choices seem to give me TCP/IP but not USB.
I've downloaded a .ppd file which is for this Epson (http://cups.org/ppd.php?L381+I0+T+Qlq+2180) but I'm not sure what to do with it. (I'm not sure whether it's already available or I have to install it and it downloaded without the .gz)
Any advice would be much appreciated.