On 06/15/2018 07:08 PM, Richard Damon wrote:
On 6/15/18 9:00 PM, Jim Lee wrote:
On 06/15/2018 05:00 PM, Chris Angelico wrote:
On Sat, Jun 16, 2018 at 4:52 AM, Rob Gaddi
<rgaddi@highlandtechnology.invalid> wrote:
On 06/15/2018 11:44 AM, Larry Martell wrote:
My favorite acronym of all time is TWAIN
Really? I always thought it didn't scan.
Having spent way WAY too many hours trying to turn documents into
images (and text), I very much appreciate that laugh.
ChrisA
I once had a Mustek color scanner that came with a TWAIN driver. If
the room temperature was above 80 degrees F, it would scan in color -
otherwise, only black & white. I was *sure* it was a hardware
problem, but then someone released a native Linux driver for the
scanner. When I moved the scanner to my Linux box, it worked fine
regardless of temperature.
-Jim
There actually may still have been a hardware issue, likely something
marginal in the timing on the cable. (Timing changing with temperature).
It would take a detailed look, and a fine reading of specs, to see if
the Windows Driver was to spec, and the hardware is marginal (but the
Linux driver didn't push the unit to full speed and got around the
issue), of if the Windows driver broke some specification but still sort
of worked, especially if things were warm, while the Linux driver did it
right.
You are exactly right. It was so long ago that I forgot some of the
details, but it boiled down to the TWAIN driver pushing the SCSI bus out
of spec. I remember looking at the bus on a scope, measuring pulse
widths, and playing with terminator values to try to optimize rise
times. I don't believe it used the Windows SCSI driver at all, but
instead drove the scanner directly (I could be remembering wrong).
-Jim
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