Digital BW, The Print

--- In DigitalBlackandWhiteThePrint@yahoogroups.com, "ray_maxwell2000" 
<rmaxwell@d...> wrote:
> 
> Hi Roy,
> 
> I would like to confirm that I have also experienced this problem.  I
> using OS X 10.3.8.  Due to requirements of other software I am using,
> I am reluctant to move back to earlier USB drivers.
> 
> This has only happen once to me while printing on Epson Premium Luster
> 250 in Rolls.  I have only had the RIP for a few weeks.
> 
> Other than this problem I am very happy with the results I am getting.
> 
> Ray Maxwell

Here's a fairly long winded account of the problem as I know it.

I tend to be leery about suggesting to others about changing "internal" things
in their OS, so I understand your hesitation.  However, I think this one is pretty
localized -- I can't be positive but I doubt anything else in your system
uses this particular program.  In Jaguar 10.2 a new print system was
introduced called CUPS -- Common Unix Printing System.  Only print drivers
that were redone for CUPS use the usb backend driver that I'm talking about.
No other usb devices go through this cups backend.

With CUPS there's one "backend" for each kind of hardware connection.
So there's a usb backend, an ethernet backend etc.  The reason you can't
use firewire is that there isn't a firewire backend -- yet, I think Tiger will have
one.  The nice thing is that drivers such as QTR don't have to even know what
kind of hardware is used for the connection.  With the old way -- Epson still
uses it -- you need a separate driver for each connection.  
If anybody's interested the backends are in:    /usr/libexec/cups/backend

When Panther came out Apple updated the usb backend and it flat out wouldn't
talk to my 7500 at all.  Being an experimenter I tried the old Jaguar usb backend
and lo and behold it worked fine.  I reported this to Apple a long time ago but
since the printer is so old I imagine the bug is very low priority for them.
I've never had a problem with my 4000 so I was surprised by the reports of
the printer backing up intermittently.   One guy had it consistently enough that
we tested a few things out.  The clincher for me was this test:
We made a 5 page print job and saved all the output from QTR in a file.  Then
we sent the "raw" file to the printer multiple times.  Interestingly, the identical
raw data showed the backup problem on different pages each time.  This at
least points to QTR not producing weird commands.

The fact that I never experienced the backup problem suggested that maybe
the Panther usb backend had a problem with the 4000 as well.  I've only had
a few people switch back to the Jaguar usb backend but so far it looks like
this is a fix to the problem.

Roy