[sane-devel] Canon D660u uses Merlin chipset (-->plustek?)

Henning Meier-Geinitz henning@meier-geinitz.de
Sun, 6 Jul 2003 00:38:28 +0200


On Sat, Jul 05, 2003 at 08:06:02PM +0000, jollyprince@juno.com wrote:
>> We know, you have mentioned that fact more than once :-)
>> But what's the connection to the article about the Canon D660u you are
>> responding to? As you yoursef wrote, the visioneer 5800 uses a
>> Realtek, not a National Semiconductor chip.

> I had been advised to model any backend that I would write after the
> Plustek project, that's all.

I think that was because we thought your scanner is based on the E5
chipset which was thought to be a National Semiconductor LM9832. But
that is not true, it's realtek. So the plustek backend is not of much
use. You can use it as a general example of an USB backend but not
much more. It's pretty complex so looking at a simpler backend like
ma1509 may make more sense.

>> Have you already asked Realtek about programming information for that
>> chip? What about Visioneer?
> No, i was led to believe this was hopeless.  Are you saying , not necessarily so.

I don't know any of these companies. When I contacted Mustek, I got
good responses, even the Windows source code for some scanners. Some
other manufacturers also cooperate so I would just try it. It may be
difficult to get the right contact addresses, however.

>> Have you read the documentation you have been ponited, to? E.g. 
>> http://www.meier-geinitz.de/sane/misc/unsupported.html
>> http://www.meier-geinitz.de/sane/misc/develop.html
>> and
>> doc/backend-writing.txt?
> Yes, I'm currently in a state of information overload and I'm saving
> everything I can get my hands on.  Right now, I'm trying to be more
> productive than that.  I'm at the crossroads.  I may well be better
> served to go shopping for a different scanner,

That will be definitely easier.

> but I simply don't know at this point.  With the information and data
> I already have maybe I can start, but I just don't know for sure.
> I've never done anything like this.
>> In your case I'd start with trying to capture the USB commands send to
>> the scanner using one of the methods explained in the docu.
> Now you're talking!  Where do I start?

Well, I just wrote it in the above sentence. Capture the USB data. The
methods how to do that are mentioned in the develop.html web page.
Also have a look at the recent discussions on sane-devel on the hp2300
scanner. While that scanner is different, the guy who wants to write
the backend also captures the commands the windows driver sends to the