Hello,
there was a patch (by Luke) recently that allowed warming up to work
for the
HP2400. The following function in execution path to fix is
gl646_search_start_position() . A way to do it is to run the backend with
all the debug, and compare this output with what it does under windows. Then
correct the function until the picture scanned to locate the start of
scanning area matches the one from windows USB log.
From time to time I upgrade the document at
http://stef.dev.free.fr/sane/genesys with informations on the genesys backend
and how to modify it. It explains also how to work with windows USB logs.
The next major hurdle one has to overcome for the 2400 if the creation
of the
slope tables that drive the stepper motor. The HP2300 and MD6471 code uses
an 'old' method with some magic constants to generate slope tables matching
those in logs, but gl841 based scanners code uses a newer and better function
that is based on the start and cruise speed needed.
There must also be some register tweaking to do, but this is easy
(places
testing for a HP2300 will give you hints) to do with a simple compare to
windows log.
Regards,
Stef
