Re: Forwards-Backwards

Peter Kirchgessner (pkirchgessner@t-online.de)
Fri, 01 Jan 1999 02:05:04 +0100

aRtsCi - Nikos Diamandis wrote:
>
> Why could my scanner which is a SE6000SP with it's own DTC3181e SCSI
> interface card, scan like crazy going let's say 10mm forwards and then 5
> backwards. Then again 10mm forwards and again 5mm backwards. After it goes
> forwards it stops and waits for some time and then it goes backwards again.
> Why? Why doesn't this happen to anyone else!? Why am I the most annoying
> person in the mailing list? Is it my fault?
> I told you I've applied the mustek-0.6. patch on a 2.0.36 kernel compiled sg
> and g_NCR5380 and used the SCSI card with it's 2 jumpers in every possible
> position. I've done everything! What is missing? Please someone! This is the
> last email I'm sending to this mailing list, because everyone tells me go and
> buy another SCSI card. I don't quit!!! I'm not surrendering at M$'s strategy.
> --
> Nikolas Diamandis
> mailto:artsci@freemail.gr
>

Hi,

I am not quite sure if I can help you. I dont know the Mustek scanners.
But I know the phenomenon from another scanner. The problem is that the
data
the scanner generates is not picked up fast enough by the application
(or the
SCSI-driver). To prevent a buffer overrun, the scanner stops until the
data
has been picked up. Then it has to continue the scan at the scanline
where
it stopped. To get sufficient scan speed, it moves a little bit backward
and then restarts scanning in the correct direction.
You may experience that the moving forward/backward is not so bad in
lineart
(b/w) mode (if it exists) because the amount of data to transmit is much
less.
Specifying an option like --speed Fastest will make it even more worse.
I am quite sure you have tried the option --speed Slowest. But maybe
this
would be in fact faster.
Unnecessary to mention that the outputfile should not be written over a
slow
network.

--Peter

-- 
Peter Kirchgessner
WWW:    http://www.kirchgessner.net
e-mail: peter@kirchgessner.net

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