Here are a couple more examples:
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Starting download ...
***** 4226: 0a should be 32
******
30,0a,31,32,33,34,35,36,37,38,39,30,0a,31,0a,
0a <===
31,32,33,34,35,36,37,38,39,30,0a,31,32,33,34
******
Starting download ...
***** 4227: 0a should be 31
******
0a
0a <===
31,32,33,34,35,36,37,38,39,30,0a,31,32,33,34
******
***** 4259: 31 should be 30
******
37,38,39,30,0a,31,32,33,34,35,36,37,38,39,31
31 <===
32,33,34,35,36,37,38,39,30,0a,31,32,33,34,35
******
Starting download ...
all downloads so far: 5041230
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Starting download ...
***** 225634: 0a should be 32
******
30,0a,31,32,33,34,35,36,37,38,39,30,0a,31,0a
0a <===
31,32,33,34,35,36,37,38,39,30,0a,31,32,33,34
******
Starting download ...
***** 225635: 0a should be 31
******
0a
0a <===
31,32,33,34,35,36,37,38,39,30,0a,31,32,33,34
******
***** 225667: 31 should be 30
******
37,38,39,30,0a,31,32,33,34,35,36,37,38,39,31,
31 <===
32,33,34,35,36,37,38,39,30,0a,31,32,33,34,35
******
Starting download ...
all downloads so far: 5041230
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It's interesting that in all cases 2 or 3 bytes are added, then 32
bytes later one is skipped.
-- Dave Strauss
On Fri, 7 Sep 2001 15:54:52 -0400, D.Strauss@motorola.com (Dave Strauss) wrote:
>
> [ ... ]
> >
> > Well, it's all a bit hairy, particularly the stuff using "test
> > mode" to figure out how many bytes were in the FIFO. Theoretically
> > I think it should cope with the printer suddenly going un-busy at a
> > bad time. If your delay is always 35 seconds long then it seems
> > unlikely that it's caused by a byte being read in unexpectedly.
> >
> > Do you know what chip your parallel port uses?
> >
> > If you have any way to find out, it would be useful to know exactly what the
> > bad data the printer is seeing is -- whether it's a data byte being
> > duplicated, or random garbage being inserted in the middle.
> >
> > p.
> >
> >
>
> Here's an example of what the printer sees. The printer is expecting
> a repeating pattern of "123456789\n", and when it sees something
> different it dumps the byte it received, what it expected, then
> some context (up to 15 bytes before, the offending byte, then up
> to 15 bytes after if they are available). It also prints the
> current byte count.
>
> After an error it tries to re-synch with the test pattern; hence the
> "Starting download ..." messages.
>
> At the end (when it gets the end marker) it prints the total count
> of bytes received. The total should be 5041228.
>
> - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
>
> Starting download ...
> ***** 668438: 30 should be 31
> ******
> 39,30,0a,31,32,33,34,35,36,37,38,39,30,0a,30
> 30 <===
> 0a,31,32,33,34,35,36,37,38,39,30,0a,31,32,33
> ******
>
> ***** 668439: 0a should be 31
> ******
> 30,0a,31,32,33,34,35,36,37,38,39,30,0a,30,0a
> 0a <===
> 31,32,33,34,35,36,37,38,39,30,0a,31,32,33,34
> ******
>
> ***** 668470: 0a should be 39
> ******
> 36,37,38,39,30,0a,31,32,33,34,35,36,37,38,0a
> 0a <===
> 31,32,33,34,35,36,37,38,39,30,0a,31,32,33,34
> ******
> Starting download ...
>
> ***** 668471: 0a should be 31
> ******
> 0a,
> 0a <===
> 31,32,33,34,35,36,37,38,39,30,0a,31,32,33,34,******
>
> all downloads so far: 5041229
>
> - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
>
> It looks like the first error was a repeat of "0" followed by
> an extra newline. The second error looks like a missing "9".
>
> -- Dave Strauss
>
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This archive was generated by hypermail 2b29 : Fri Sep 07 2001 - 16:28:37 EDT