[363] in linux-scsi channel archive
Reading more than buffersize
daemon@ATHENA.MIT.EDU (Christian Ullenboom)
Thu Jul 13 20:01:00 1995
From: Christian Ullenboom <ulliull@uni-paderborn.de>
To: linux-scsi@vger.rutgers.edu
Date: Thu, 13 Jul 1995 13:37:22 +0200 (MET DST)
Hi Folks,
A few days ago I bought a Fledbed Scanner which I am now trying to access under
linux. If I am scanning a whole line with 8.5" at 1200dpi I would have to
read 10200 bytes, but with a single read-command (SCSI-Command 0x08) I can
only get about 4000 byte (plus the SCSI-Header). My Scanner (a Mustek MSF-6000cx)
can only send whole lines, so without patching the kernel in order to get a bigger
inputbuffer scanning a whole line at 1200dpi is impossible.
Another disadvantage of getting only a few lines at one read is, that the scanner
stops for a few milliseconds after every read-command and so a smooth scanning is
not possible and in the scanned image you can see positioning errors (doublescanned
lines etc.).
So how can I get more then 4000 byte with a single read-command without patching
the kernels buffersize. Scanning the whole page (8.5" x 14") at 300dpi with 255
colors would lead to 10Megs of data !!!
thanks for answering,
Matthias Greim
P.S.: please also write your answer to ulliull@uni-paderborn.de because I am
not on the linux-scsi-mailing list !!!
