[Gllug] HP Photosmart 7550

[John Hearns]

On Sun, 2002-12-29 at 08:46, Eric Lee wrote:
> versions, but no luck so far.  I just get pages that read:
> 
> %!PS-Adobe-3.0
> %%Creator: Gnore Print Version 0.35
> %%Creation Date: D:2002122710594
> 
Eric, as you have no doubt by now figured out this is the printer
printing out a raw Postscript file.
The first two characters %! identify it as such,
and then it goes on to say level 3. I guess your printer does not
recognise this.
In your next email you have changed to level 2, and a different 
filter program to create the Postscript.
I cannot diagnose your exact problem with the Evolution and AbiWord
printing, but I bet that they are still using the Gnome printing with
level 3 output.


It might help some other people if we discuss this a bit further?

It is a long time since I delved deep into Postscript, but here goes.
Postscript is a page description language developed by Adobe systems.
So it describes to printers, and other output devices such as the
machines used to print books and magazines, how a page should exactly
look like. PS was also used by Sun(?) and Next in the windowing systems
of their workstations.

Postscript is the end result of a production chain - so you normally
work with (say) a LaTEX or a Word document, then do the final conversion
to Postscript before sending it to the printer. 

The printer itself will contain a language interpreter, which reads the
Postscript and converts this into the specific commands which the
printers electronics use to produce the page. 
So the printer itself has to be a small computer - this is why PS
printers tend to be more expensive, and also why you see RAM sizes being
listed for them.
(as an aside, someone has run Linux on an HP laserjet!)

A Postscript file is a sequence of ASCII characters - even the graphics
on the page are encoded this way. So you can edit the file with a normal
text editor, and maybe do some small tweaks on it if really needed.


http://www.cs.indiana.edu/docproject/programming/postscript/postscript.html


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