You have to set the printer up like this:-

Kmenu - KNOPPIX - Configure - configure printer(s)

enter root password (blank on live CD - so you may need to open a root shell and enter a password with 'passwd' to get past this stage).

Select Add - Add Printer/Class this gives you a wizard, select 'HP' and then scroll down the list to 'laserjet 5' and follw the wizard through. (including printing a test page).

That should do it.

Stoo.....