Baslinux mailing list

[Sindi Keesan <keesan AT iamjlamb.com>]

Twice now people have sent me 200x200 dpi pdf files made with a scanner 
that for some reason they set to scan at fax quality.  The scanner 
operators have no idea how to scan at 300x300 dpi.  When I print them 
at 150x150 or 300x300 dpi they are not as legible as they should be 
because the dots get interpolated (different numbers of dots from the 
original file).  They look much better viewed onscreen as image files but 
it is a blasted nuisance to translate 20-30 pages onscreen, so I would 
prefer to print them.  


(By the way, all of my image viewers display these files much much faster
than any pdf or ps viewer I tried, nearly instantaneously at 1600 dpi. The
pdf and ps files consist of the usual long string of ASCII characters
representing an image, plus a lot of irrelevant junk about font colors
styles sizes that the program needs to read every time.)

I have HP 500 and 600 series printers which print in DOS or LINUX (gs 
deskjet or djet500 drivers) at up to 300 dpi.  We were also given two 
working 600x600 dpi 'Windows' printers (HP 820Cse and HP 722C - one 
because it 'did not work' until the cartridge was pushed in all the way) 
that don't even have Mac drivers (Canon sometimes provides both).
At the end of this posting is the explanation of how HP constructed them.

A search in google/linux under 722C reveals that there are pbm2ppa 
(greyscale) and pnm2ppa (color) drivers for i386 which appear to require 
the kernel and libraries of no later than RH6.1 (at least the older 
versions, dating from 2000).  The oldest version binary .tar.gz for redhat 
is 63K color and 32K BW.  There is also a Redhat 6.1 'filter'.

Apart from running them through some rpm to tgz program (mc-menu) what do 
I do to get these drivers to work with ghostscript?  

Here is how these HP 'Windows' printers work:

   PPA  (Printing  Performance  Architecture)  is  a  closed, proprietary
   protocol  developed  by  Hewlett  Packard  for a short-lived series of
   DeskJet  printers.  In  essence,  the PPA protocol moves the low-level
   processing  of  the data to the host computer rather than the printer.
   This allows for a low-cost (to produce) printer with a small amount of
   memory and computing power. However, in practice the printer was often
   as  expensive  as  more capable printers and HP has since discontinued
   the  use  of  PPA  in  favour  of  returning  to PCL3e in their latest
   USB-based printers.

   This  project  is  a testament to open source persistence to develop a
   workable  solution  for  a  proprietary  platform despite the original
   manufacturer being extremely unhelpful.


------- 
The cartridges are also a real pain to fill and need to be left
overnight for the pressure to equilibrate or they will leak all over the
computer.  We bought a quart of ink for this particular cartridge to fill
them for two friends who have decided it is not worth it, and we therefore
have lots of ink and an endless supply of lightly-used cartridges for
these two models.  HP clearly did not design them for reuse.  I think you 
need to drill a hole and then glue it shut.  The 500 and 600 series 
cartridges are easier to fill.

Panasonic KXP1124 dot-matrix are much easier to reink - drop 10 or so 
drops of ink onto the foam pad inside the cartridge housing the ribbon and 
then spin the ribbon through the pad using an electric drill (or by hand 
if so inclined).  $10 including shipping reinks a lifetime supply but the 
ribbons will eventually wear out.


These HP 700/800/1000 color models are at least non-USB and it might be 
worth grabbing one if you find it and want to print 600 dpi with linux.

Sindi Keesan