techblog 

It is rare that the OSX interaction designers get it wrong, but this is one of those cases and it is a whopper.

We have an HP DesignJet 120nr in the office, basically a big (A0) printer, networked up for us to share.  I’d only ever used it from a Windows box before but I needed to set it up on OSX.  My first step was to open System Preferences then Print and Fax and press the + to add a new printer.  Then I selected LPD printing and typed in the queue name, which it duly recognised as a valid queue.

However it did not auto-detect the printer type and decided it was a Generic Postscript Printer.  So I dropped down the list of drivers, found HP on the list, but I could not see the DesignJet 120nr on that list.

This seemed pretty obvious to fix, just install the drivers.  I downloaded those after a bit of hassle because HP make you register to get them (so old-fashioned) and installed them.  But still the printer did not appear in the list.

I then spent ages looking at files like hpdjPM.plugin and trying to work out how it all fitted together but got nowhere.  I could clearly see from the installer log that the right driver was installed in :Libary:Printers:hp:deskjet:hpdjPM.plugin:Contents:Resources:XMLData:Printers:designjet_120nr.xml but it would not appear in that list.  I tried fixing disk permissions, which found a lot of errors around there but that still did not work.

Finally I spotted a clue on the web that gave me an idea as to how it works.

I went to the same screen but instead of filling anything in, just pressed the ‘More Printers …’ button.  Then I selected ‘HP IP Printing’ from the drop down at the top.  The screen then has two tabs, Auto and Manual.  Auto was blank so I guess that uses a local subnet broadcast and Manual asks for an IP address.  After all this fiddle using dig to get the printer’s IP address is trivial but still something I should not have to do.  Anyway I did that, entered the IP address and pressed Add.  After a several second delay it flipped back to the printer screen with my new printer correctly identified as a DesignJet 120nr and even had the right icon.

What a fuss.