Re: Mustek Scanner distorted image lines

becka@sunserver1.rz.uni-duesseldorf.de
Tue, 13 May 1997 00:33:47 +0200 (MET DST)

> - 128k SCSI buffer

> The scanner is a MFS-12000SP which says
> Host: scsi1 Channel: 00 Id: 06 Lun: 00
> Vendor: SCANNER Model: Rev: 1.00
> Type: Scanner ANSI SCSI revision: 01 CCS
Here I have :

Vendor: MUSTEK Model: MFS-12000SP Rev: 1.00
Type: Scanner ANSI SCSI revision: 01

> The problem is that about every 128kBytes in the image 1 or two scan
> lines of garbage seem to be added (I think sometimes lines are
> missing, too).
This is probably due to a bad color-correction scheme. I added an alternate
scheme for my scanner which doesn't use backtracking, but sends R,G,B at
1/72" offset. The correction code influences particularly the start and
end of a complete SCSI Buffer. Please check out, if the following section
of code gets activated for you :

/* Revision 1.00 of the MFS-12000SP firmware is buggy and needs
this workaround. Maybe others need it too, but this one is
for sure. We know for certain that revision 1.02 or newer
has this bug fixed. */
if (fw_revision < 0x102)
dev->flags |= MUSTEK_FLAG_LD_MFS;

Then change it to be (de-)activated depending on what was the state before.

I suppose this should correct the problem. please report what happened, so
we can add auto-detection. MUSTEK should be shot for not counting up
Firmware-Revision ...

> The distorted lines also appear in modes other than Color. I'm pretty
> sure (90%) that I had a similar distortion when I once had the scanner
> connected to the NCR53C400 card.
This shouldn't happen. Please check, if 10% are the case ;-)
The correction code which is the most probable cause, is only activated in
color mode.

CU,Andy

-- 
Andreas Beck              |  Email :  <becka@sunserver1.rz.uni-duesseldorf.de>
===  World-Wide-Web URL :  http://sunserver1.rz.uni-duesseldorf.de/~becka  ===

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