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Hi Jerry,<br><br>The short answers to your questions are:<br><br>(1) Distinguishing Emulation from Genuine was not a<br>design objective.<br><br>(2) Distinguishing PDL versions was also not a design<br>objective (or plausibly interoperable).<br>
- The use and misuse of the corresponding version<br>elements in the Printer MIB v1/v2 prtInterpreterTable<br>is a hopeless mess.<br>- Nobody was willing to let the editors to address this<br>when we did Printer MIB v2.<br>
<br>So, inserting version information may work for a given<br>vendor, but completely breaks interoperability across<br>different spoolers and OS environments.<br><br>We could perhaps introduce a syntax for version<br>suffixes, but the chances that vendors will correctly<br>
implement it seems very unlikely.<br><br>Bearing in mind the machine-readability imperative,<br>do you have an interoperable version suffix format<br>to propose? <br><br>Or an interoperable Emulation versus Genuine suffix<br>
format?<br><br>Cheers,<br>- Ira (1284 Cmd Set editor)<br><br clear="all">Ira McDonald (Musician / Software Architect)<br>Chair - Linux Foundation Open Printing WG<br>Co-Chair - TCG Hardcopy WG<br>IETF Designated Expert - IPP & Printer MIB<br>
Blue Roof Music/High North Inc<br>email: <a href="mailto:blueroofmusic@gmail.com">blueroofmusic@gmail.com</a><br>winter:<br> 579 Park Place Saline, MI 48176<br> 734-944-0094<br>summer:<br> PO Box 221 Grand Marais, MI 49839<br>
906-494-2434<br>
<br><br><div class="gmail_quote">On Wed, Jan 27, 2010 at 11:58 AM, William Wagner <span dir="ltr"><<a href="mailto:wamwagner@comcast.net">wamwagner@comcast.net</a>></span> wrote:<br><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
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<p class="MsoNormal"><span style="font-size: 14pt; color: rgb(31, 73, 125);">Hi Jerry,</span></p>
<p class="MsoNormal"><span style="font-size: 14pt; color: rgb(31, 73, 125);"> </span></p>
<p class="MsoNormal"><span style="font-size: 14pt; color: rgb(31, 73, 125);">I am sending your questions onto Ira. I think your two points
are very good ones. My take on them:</span></p>
<p class="MsoNormal"><span style="font-size: 14pt; color: rgb(31, 73, 125);"> </span></p>
<p class="MsoNormal"><span style="font-size: 14pt; color: rgb(31, 73, 125);">The spec allows for </span><span style="font-size: 14pt;">PrtInterpreterLangFamilyTC, mime-media-type,
and </span><span style="font-size: 14pt; color: rgb(31, 73, 125);">Private type designations. </span><span style="font-size: 14pt;">PrtInterpreterLangFamilyTC does not provide
for version and emulation variations; mime-types for all of the variations do not
exist, and would be cumbersome if they were to be all registered; and having applications
understand the difference between private types is unrealistic.</span></p>
<p class="MsoNormal"><span style="font-size: 14pt;"> </span></p>
<p class="MsoNormal"><span style="font-size: 14pt;">The
intent is machine identification of the command language. Just indicating (by
an appropriate means… placing “emulation” after the designation
does not appear consistent with the spec) that a pdl is an emulation
warns the interpreter that there may be differences from the defined set, but these
will likely be different from one emulation to another. I think the best approach
depends on how good the emulation is (as an emulation, not as a PDL). But, barring
having to define and designate each emulation as a separate PDL, there
might be some benefit in somehow flagging that a PDL might deviate somewhat
from the defined language.</span></p>
<p class="MsoNormal"><span style="font-size: 14pt;"> </span></p>
<p class="MsoNormal"><span style="font-size: 14pt;">Major
Version differences are likely more drastic, more likely to be independently
defined and since there should be fewer of them that possible emulations, more
amenable to being listed as separate MIB or MIME types. That is, there is
little advantage in knowing the language is up-version (other than
expecting differences) unless the interpreter knows what the differences are.
To be able to do this, the version and its definitive reference should be
identified in a standard way. The problem then, of course, is who is going to
register these versions.</span></p>
<p class="MsoNormal"><span style="font-size: 14pt;"> </span></p>
<p class="MsoNormal"><span style="font-size: 14pt;">Thanks
for the input.</span></p>
<p class="MsoNormal"><span style="font-size: 14pt;"> </span></p>
<p class="MsoNormal"><span style="font-size: 14pt;">Bill
Wagner</span><span style="font-size: 14pt; color: rgb(31, 73, 125);"></span></p>
<p class="MsoNormal"><span style="font-size: 14pt; color: rgb(31, 73, 125);"> </span></p>
<p class="MsoNormal"><span style="font-size: 14pt; color: rgb(31, 73, 125);"> </span></p>
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<p class="MsoNormal"><b><span style="font-size: 7.5pt;">Jerry
Thrasher/Lex/Lexmark</span></b> </p>
<p><span style="font-size: 7.5pt;">01/27/2010
09:07 AM</span> </p>
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<p class="MsoNormal" style="text-align: right;" align="right"><span style="font-size: 7.5pt;">To</span></p>
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<p class="MsoNormal"><span style="font-size: 7.5pt;">"William
Wagner" <<a href="mailto:wamwagner@comcast.net" target="_blank">wamwagner@comcast.net</a>></span> </p>
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<p class="MsoNormal" style="text-align: right;" align="right"><span style="font-size: 7.5pt;">Subject</span></p>
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<p class="MsoNormal"><span style="font-size: 7.5pt;">Re:
[Pwg-Announce] PWG last call - Command Set Format - IEEE1284 Device
ID -25 Feb 2010</span></p>
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<p><br>
<br>
<span style="font-size: 10pt;">Bill,</span> <br>
<br>
<span style="font-size: 10pt;">A couple of
questions have come up with respect to what's really required to be done and
what</span> <br>
<span style="font-size: 10pt;">can be done
with respect to two particular issues.</span> <br>
<span style="font-size: 10pt;">1. The percieve
requirement for not confusing PDL emulation with "true" PDL support</span>
<br>
<span style="font-size: 10pt;">Example,
Postscript Emulation vs. Adobe PostScript and PCL Emulation vs. HP PCL support.</span>
<br>
<span style="font-size: 10pt;">2. The need for
the ability for versioning of the various PDLs.</span> <br>
<span style="font-size: 10pt;">PCL 6 is very
different from PCL 3 (most low end inkjet printers still support only PCL 3,
the first</span> <br>
<span style="font-size: 10pt;">PCL to support
color).</span> <br>
<br>
<span style="font-size: 10pt;">So here's what
I'm talking about from a real string.</span> <br>
<span style="font-size: 10pt;">Example:</span>
<br>
<span style="font-size: 10pt;">If the current
CMD string is:</span> <br>
<br>
<span style="font-size: 10pt;">COMMAND
SET:PCL 6 Emulation, PostScript Level 3 Emulation, NPAP, PJL;</span> <br>
<br>
<span style="font-size: 10pt;">Would a
compliant string simply be:</span> <br>
<br>
<span style="font-size: 10pt;">COMMAND
SET:PCL,PS,PCL 6 Emulation, PostScript Level 3 Emulation, NPAP, PJL;</span> <br>
<span style="font-size: 10pt;"><br>
</span>_____________________________________ </p>
<p><img src="cid:image001.gif@01CA9F42.965E49A0" alt="LEXMARK" height="46" width="164"><span style="font-size: 10pt; color: rgb(102, 102, 102);"> <b><br>
Jerry Thrasher</b><br>
Senior Engineer, WW Corporate Standards<br>
C14/082-1, 740 New Circle Rd, Lexington Ky 40550<br>
Office: +1 859 825 4056 Fax: +1 859 232 7628<br>
thrasher(at)lexmark(dot)com</span></p>
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