Re: Patch for Microtek ScanMaker X6 (microtek2 backend)

Sebastian Erdmann (serdmann@cs.tu-berlin.de)
Sun, 22 Nov 1998 07:00:05 +0100 (MET)

On Sat, 21 Nov 1998 17:24:57 +0100, Bernd Schroeder writes:
>
> On Fri, Nov 20, 1998 at 01:41:21PM +0100, Sebastian Erdmann wrote:
[...]
> > I tried every computer/scanner power-up sequence I could think of :-)
> > I also tried loading/unloading the SCSI driver, but the problem occurs
> > every time. It doesn't seem to be related to SCSI, since it occurs on
> > both the Adaptec AVA-1505 host adapter (supplied with the scanner)
> > and my NCR 53C810 controller.
>
> But I still don't understand why the device doesn't work after it is
> powered on, and then works better, if it switched off an on again.

I don't understand it, either. :-(

[...]
> The reason why I am somewhat sceptical about this "send diagnostics" is
> that I think it is an overkill to introduce a command that costs a lot
> of time and additional movements of the scan head (and may have side effects)
> to work around a problem, that occurs only once after the scanner is powered
> on.

Unfortunately, the problem isn't gone after the first scan -- it
persists until the scanner is power-cycled or a "send diagnostics"
command is sent. Also, the problem is present in all scan modes
(line art, greyscale and color -- didn't test the 12-bit modes, though)

[...]
> The next release will have an option "disable backtracking", and it can
> be configured in the configuration file, whether this option will be
> visible in the frontend or not. If not it is set to a default value.
> Some other less important options will follow (bind resolution is another
> candidate). The purpose is to have less active options in order to reduce
> the height of the xscanimage window, because on small screens and with
> low resolutions xscanimage exceeds the size of the screen.
>
> So something like 'option fix-thisorthatproblem on/off'
> in the configuration file, that activates/deactivates a respective
> boolean option in the frontend might indeed be useful (one for each problem).

That's a neat idea.

> But I strongly recommend to set the default value for this
> "send diagnostics" to "off" (and never activate it if it is not an X6) :) .

Agreed. :-)

> It looks as if you have the documentation, so if iyou discover anything that
> explains, why these problems occur, please let me know.

I got the SCSI command set documentation from Microtek's USA FTP site.
Reading it back-to-back didn't reveal anything particular enlighting
(except for that ugly "send diagnostics" workaround...)

I'll keep you informed.

Sebastian

-- 
                                        ___
Sebastian Erdmann                      /
serdmann@cs.tu-berlin.de           ___|__
se@pobox.com                      (_  |
http://pobox.com/~se              __)  \___



--
Source code, list archive, and docs: http://www.mostang.com/sane/
To unsubscribe: echo unsubscribe sane-devel | mail majordomo@mostang.com