BIG printer setup for Ubuntu?

[Phillip Sc. Boegh]

Hi Ubuntu's

I am supporting a layout company to swich to Linux, but got problems with
big scale printers.
In a local LUG I have heard that the BIG printers (and maybe plotters) can
CUPS usenetwork Generic postscript printer drivers. But in (old)
Mackintosh and in windows a server program for these big printers comes
after the driver called RIP server application for setting up colors, size
and printing materials such as linnet and plast etc. for banners, signs
etc.

The actual printers are: HP-DesignJet_3000CP , Xerox DC50 (Document Centre
printer model 50) and on theRoland CJ500 (comjet).

I do not realy get into using Cups as neither my root+password OR my
general user + userpassword are usefull for CUPS at the:
http://localhost:631/admin

Haw can I get access?

Best regards

Phillip