[sane-devel] Re: [Fwd: Re: TWAIN-SANE for microtek slimscan c6 usb]

[Karsten Festag]

Hi,

I must admit that I have not planned to convert the microtek2 backend for 
using threads. And I doubt if this is the solution because under linux the 
microtek2 - USB- scanners only work with a special kernel module 
(microtek.o). This module makes the USB-scanner appear as a SCSI device to 
the backend (the backend only knows SCSI). As far as I know there is no such 
a module in OS X. 
A possible solution might be to include the translating code into the 
microtek2 backend and use libusb. I don't have the time to do this now and I 
have no USB scanner for testing available but you are welcome to try to do 
this work.
The kernel module for Linux was written by 
John Fremlin <vii@penguinpowered.com> and
Oliver Neukum <Oliver.Neukum@lrz.uni-muenchen.de>
Maybe they can help you more than I can.

Sorry for the bad news.

Best regards

Karsten



On Saturday 14 February 2004 03:03, you wrote:
> Hello,
>
> I wrote to Mattias Ellert concerning the microtek2 backend (for slimscan C6
> USB) and Mac OS X and he suggested I contact to you to find out if there is
> a time line for converting the backends to use threads instead of forks for
> microtek2
>
> Also I was wondering if this backend should work from a Mac booted into
> Yellowdog linux 3.0.1.  The backend is included as part of the Yellowdog
> distribution.   I recently tried this on my eMac using GIMP but Xsane
> indicated it couldn't find any devices.
>
> Thanks in Advance,
>
> - John
>
> > From: Mattias Ellert <mattias.ellert@tsl.uu.se>
> > Date: 2004/02/05 Thu AM 02:53:33 EST
> > To: jrlannon1@cox.net
> > CC: karsten.festag@gmx.de
> > Subject: Re: TWAIN-SANE for microtek slimscan c6 usb
> >
> > jrlannon1@cox.net wrote:
> > > Mr. Ellert,
> > >
> > > I am wondering if the Microtek Slimscan C6 USB is
> > > supported under Panther (10.3.2) using the TWAIN-SANE
> > > Interface?  The SANE backend does exist for this
> > > scanner.  However, I have noticed some caveats for USB
> > > scanners (and USB Scanners with SCSI circuitry in
> > > particular).
> >
> > Almost all the backends that exist can be complied on MacOS X (except
> > for the parallel port ones). Some of them does not work however. The
> > most common reason why it won't work is that the combination of USB and
> > fork does not work on MacOS X because the forked child process does not
> > inherit the access rights to the USB pipes opened by the parent process.
> >
> > If you have installed the sane libraries and the scanimage command from
> > the command line does not work this is probably the reason why it
> > doesn't work, since looking at the code for the backend you are using
> > (microtek2) shows that it does indeed use a fork call on MacOS X.
> >
> > This can be fixed by using a thread instead of a forked child process.
> > The process of converting the backends to use threads instead of forks
> > is an ongoing effort. The backend you are using has not yet been
> > converted. If you are interested in the time plan for this to happen you
> > should contact the maintainer of the backend at karsten.festag@gmx.de.
> >
> > The UMAX backend was recently successfully converted in this way.
> >
> > 	Mattias
> >
> > --
> > ________________________________________________________________________
> >
> > mattias.ellert@tsl.uu.se                           tel: +46 18 471 32 58
> > http://www.tsl.uu.se/~ellert/                      fax: +46 18 471 35 13
> > ________________________________________________________________________