sane-project-backends/doc/sane-apple.man

.TH sane-apple 5 "13 May 1998"
.IX sane-apple
.SH NAME
sane-apple - SANE backend for Apple flatbed scanners
.SH DESCRIPTION
The
.B sane-apple
library implements a SANE (Scanner Access Now Easy) backend that
provides access to Apple flatbed scanners. At present, the following
scanners are supported from this backend:
.PP
.br
----------- ----------- ------------------ -----
.br
AppleScanner 4bit 16 Shades of Gray
.br
OneScanner 8bit 256 Shades of Gray
.br
ColorOneScanner 24bit RGB color 3-pass

.PP
If you own a Apple scanner other than the ones listed above that
works with this backend, please let us know by sending the scanner's
model name, SCSI id, and firmware revision to
.IR sane\-devel@mostang.com .

.SH "DEVICE NAMES"
This backend expects device names of the form:
.PP
.RS
.I special
.RE
.PP
Where
.I special
is either the path-name for the special device that corresponds to a
SCSI scanner. For SCSI
scanners, the special device name must be a generic SCSI device or a
symlink to such a device.  Under Linux, such a device name could be
.I /dev/sga
or
.IR /dev/sge ,
for example.  See sane-scsi(5) for details.
.SH CONFIGURATION
The contents of the
.I apple.conf
file is a list of options and device names that correspond to Apple
scanners.  Empty lines and lines starting with a hash mark (#) are
ignored.  See sane-scsi(5) on details of what constitutes a valid
device name.
.PP
Options come in two flavors: global and positional ones.  Global
options apply to all devices managed by the backend whereas positional
options apply just to the most recently mentioned device.  Note that
this means that the order in which the options appear matters!

.SH SCSI ADAPTER TIPS
SCSI scanners are typically delivered with an ISA SCSI adapter.
Unfortunately, that adapter is not worth much since it is not
interrupt driven.  It is (sometimes) possible to get the supplied card
to work, but without interrupt line, scanning will put so much load on
the system, that it becomes almost unusable for other tasks.
.SH FILES
.TP
.I @CONFIGDIR@/apple.conf
The backend configuration file (see also description of
.B SANE_CONFIG_DIR
below).
.TP
.I @LIBDIR@/libsane-apple.a
The static library implementing this backend.
.TP
.I @LIBDIR@/libsane-apple.so
The shared library implementing this backend (present on systems that
support dynamic loading).
.SH ENVIRONMENT
.TP
.B SANE_CONFIG_DIR
This environment variable specifies the list of directories that may
contain the configuration file.  Under UNIX, the directories are
separated by a colon (`:'), under OS/2, they are separated by a
semi-colon (`;').  If this variable is not set, the configuration file
is searched in two default directories: first, the current working
directory (".") and then in @CONFIGDIR@.  If the value of the
environment variable ends with the directory separator character, then
the default directories are searched after the explicitly specified
directories.  For example, setting
.B SANE_CONFIG_DIR
to "/tmp/config:" would result in directories "tmp/config", ".", and
"@CONFIGDIR@" being searched (in this order).
.TP
.B SANE_DEBUG_APPLE
If the library was compiled with debug support enabled, this
environment variable controls the debug level for this backend.  E.g.,
a value of 255 requests all debug output to be printed.  Smaller
levels reduce verbosity.

.SH CURRENT STATUS
The apple backend is now in version 0.3 (Tue Jul 21 1998). Since
I only have the AppleScanner and not the other models (OneScanner,
ColorOneScanner) I can only develop/test for the AppleScanner effectively.
However with this release I almost complete the gui part of all scanners.
Most of the functionality is there. At least OneScanner should scan
at the AppleScanner's compatible modes (LineArt, HalfTone, Gray16). My
personal belief is that with a slight touch of debugging the OneScanner
could be actually usable. The ColorOneScanner needs more work. AppleScanner
is of course almost fully supported.

.SH MISSING FUNCTIONALITY
Currently all 3 models are lacking upload/dowload support.
.TP
.B AppleScanner
Cannot up/download a halftone pattern.
.TP
.B OneScanner
Cannot up/download halftone pattern and calibration vector.
.TP
.B ColorOneScanner
Cannot up/download halftone pattern, calibration vectors,
custom Color Correction Table (CCT) and of course custom gamma tables.
.TP
.B Park/UnPark (OneScanner, ColorOneScanner)
.PP
The above functionalities are not only missing because I don't actually
have the hardware to experiment on it. Another reason is the lack
of understanding of how SANE API could provide enaugh means to me
to actually describe other array types than the gamma one.

.SH UNSUPPORTED FEATURES.
The following "features" will never be supported. At least as I am maintaining
the sane-apple backend.
.TP
.B NoHome (AppleScanner)
The scanner lamp stays on and the carriage assembly remains where it stops
at the end of the scan. After two minutes, if the scanner does not receive
another SCAN command the lamp goes off and the carriage returns to the home
position.
.TP
.B Compression (AppleScanner)
Scanner it can compress data with CCITT Group III, one dimensional algorithm
(fax), and the Skip White Line algorithm.
.TP
.B Multiple Windows (AppleScanner)
AppleScanner may support multiple windows. That it would be a cool feature
and a challenge for me to code it if you could intermix different options
for different windows (scan areas). This way you could scan a document
in LineArt mode but the figures in it on Gray and in a different resolution.
Unfortunately this is impossible.
.TP
.B Scan Direction (OneScanner)
It controls the scan direction. (?)
.TP
.B Status/Reset Button (OneScanner)
This option controls the status of the button in OneScanner model. You can
also reset the button status by software.

.SH BUGS
The bugs in a sane backend are divided in two classes. We have
.B GUI
bugs and
.B scanner specific
bugs.
.PP
We know we have a GUI bug when a parameter is not showing up itself when it
should (active) or vice versa. To find out which parameters are active
accross various Apple modes and models from the documentation
.B ftp://ftpdev.info.apple.com/devworld/Technical_Documentation/Peripherals_Documentation/
is an interesting exercise. I may missed some dependancies. For example
for the threshold parameter the Apple Scanners Programming guide says
nothing. I had to assume that is valid only in LineArt mode.
.PP
Scanner specific bugs are mostly due to mandatory round offs in order to
scan. In the documentation in some place states that the width of the
scan area should be a byte multiple. In an other place says that the
width of the scan area should be an even byte multiple. Go figure...
.PP
Other source of bugs are due to scsi communcation, scsi connects and
disconnects. However the classical bugs are still there. So you may
encouter buffer overruns, null pointers, memory corruption and
.B SANE
API violations.
.TP
.B SIGSEGV on SliceBars
When you try to modify the scan area from the slice bar you have a nice
little cute core dump. I don't know why. If you select the scan are from
the preview window, or by hand typing the numbers everything is fine. The
SIGSEGV happens deep in gtk library (gdk). I really cannot debug it.
.TP
.B Options too much
It is possible, especially for the ColorOneScanner, that the backend's
options panel to exceed from your screen. It happens with mine
and I am running at 1024x768 my X Server. What can I say? Try smaller
fonts in the X server, or virtual screens.
.TP
.B Weird SCSI behaviour.
I am quoting David Myers Here...

>> OS: FreeBSD 2.2.6

>> CC: egcs-1.02

>Just wanted to follow up on this...  I recently changed my SCSI card from

>the Adaptec 2940UW to a dual-channel Symbios 786 chipset.  When I started up

>SANE with your driver, I managed to scan line art drawings okay, but Gray16

>scans led to a stream of SCSI error messages on the console, ultimately

>hanging with a message saying the scanner wasn't releasing the SCSI bus.

>This may be that the Symbios is simply less tolerant of ancient

>hardware, or may be bugs in your driver or in SANE itself...

.SH DEBUG
if you encounter a GUI bug please set the environment variable
SANE_DEBUG_APPLE to 255 and rerun the excact sequence of keystrokes
and menu selections to reproduce it. Then send me a report with the
log attached.
.PP
It would be very helpfull if you have handy an Apple machine (I am not sure
how Mackintos are spelled) with the AppleScanners driver installed and check
what option are grayed out (inactive) in what modes and report back to me.
.PP
if you want to offer some help but you don't have a scanner or you
don't have the model you would like to offer some help, or you are
a sane developer and you just want to take a look at how the apple backend
looks like. Goto to apple.h and #define the NEUTRALIZE_BACKEND
macro. You can select the scanner model through the APPLE_MODEL_SELECT
macro. Available options are APPLESCANNER, ONESCANNER, COLORONESCANNER.
.PP
if you encounter a SCSI bus error or trimmed and/or displaced images please
also set the environment variable SANE_DEBUG_SANEI_SCSI to 255 before sendme
the report.

.SH TODO
.TP
.B Non Blocking Support
Make sane\-apple a non blocking backend. Properly support for
.B sane_set_io_mode
and
.B sane_get_select_fd
.TP
.B Scan
Make scan possible for all models in all supported modes.
.TP
.B Missing Functionality.

.SH "SEE ALSO"
sane(7), sane\-scsi(5)

.SH AUTHOR
The sane-apple backend was written not entirely from scratch by
Milon Firikis. It is mostly based on the mustek backend from
David Mosberger and Andreas Czechanowski