Hope I don't waste bandwidth for everyone, but I didn't get Mark's
e-mail address from his message (MS-Mail, ain't it great?  not!)
So here are my quick answers.
If you need/want more details, e-mail me privately.
Terry Simpkins

  1) Did you have/purchase parallel interfaces on your 256x printers OR did
     you use a parallel-serial converter?
>>> actually we have used two different solutions.  preferred is to put a parallel
card in the 256x and use a JetDirect EX box from HP.  Otherwise, we connect
them serially to an Intel NetportExpress Pro's serial port  (if we have several
printers sitting next to each other, this saves IP addresses)

  2) Do you send 256x control characters embedded in your prints (similar to
     PCL codes to a laser printer) or environment files, and do they work?
>>>  I don't know of any, generally what gets sent to these printers is plain-old
line printer reports from our application (MANMAN).  All "forms" printing is
done on LaserJets via Fantasia

  3) Were there any particular NPCONFIG parameters you had to set up for this
     to work?
>>>  Here is an entry right from our NPCONFIG.PUB.SYS file:
4000   (network_address = xxx.xxx.xxx.xxx
        PJL_SUPPORTED = FALSE
        JAM_RECOVERY = FALSE)
#  line printer (HP2563A w/Parallel card) - slough


  4) Have you had any problems with this configuration?
>>>  None other than getting the parallel cards installed and configured.
That said, I do have one just installed at a site in the UK that isn't working yet.
Of course the person there has never seen an HP3000 or HP printer, and
we are still working on the printer configuration.