From: earle@elroy.jpl.nasa.gov (Greg Earle - Gainfully Unemployed)
Subject: Class 2 FAX modem AT commands documentation (Re: Telebit FAX upgrade)
Followup-To: comp.dcom.modems,biz.comp.telebit
Keywords: Telebit  FAX  documentation
Organization: Gainfully unemployed
Date: Fri, 8 Jan 1993 10:35:14 GMT

In article <1993Jan7.231020.10297@netcom.com> mingso@netcom.com (Ming Yau So) writes:
>In article <1993Jan6.182313.22435@news2.cis.umn.edu> alla0008@student.tc.umn.edu (Graham Allan) writes:
>>In article <1993Jan6.100623.15326@elroy.jpl.nasa.gov> isolar!earle@elroy.JPL.NASA.GOV writes:
>>> [about lack of documentation for fax commands]
>>You can get hold of documents describing the Class-1 and Class-2 protocols
>>from several BBS's - I saw a copy which had originated from Supra.
>
>If my memory serves well, I remembered when I read the Supra's doc (either on
>paper or from their BBS), it says that the documentations for Class 1 & 2
>fax protocols (V.17 & V.29 ??) are copyrighted by CCITT, and it's CCITT desire
>to not have these docs distributed freely from the modem manufacturer, because
>CCITT are selling these docs (very expensive, I recalled) to survive.  And I
>think the docs described in the Telebit's doc might be these CCITT docs. 

Even if Telebit was enjoined from distributing a version of the modem commands
for FAX, by CCITT or otherwise, don't you think that the least they could do
is to *tell* you that, and direct you to where you *can* purchase them?  If I
had no Usenet access, I'd have no idea what to do/where to go.  That is part
of my point - a little information is better than no information, which is what
I got for my $99 - no information.

>If yes, I think you shouldn't flame Telebit that much.  Anyway, if you need
>those docs, I think you can buy them CCITT directly, though they are likely
>to be expensive.  BTW, I think all of the FAX modems which conforms to the
>CCITT standards use the same set of commands for basic FAX capabilities (like
>the AT commands for low speed data modems), e.g. they all use AT+FCLASS=? to
>determined the supported FAX protocols.

Sure, I know this.  But again, you are missing the point:

The "AT" command set to operate the modem in Data Mode is completely and
(reasonably) thoroughly documented in the Telebit manual set.  I've absolutely
no quibbles with this at all.

The "AT" command set to operate the modem in FAX Mode - "+FCLASS" et al. - is
NOT DOCUMENTED IN THE SLIGHTEST in the Telebit manual set.  There is no excuse
in my mind for not providing either the documents themselves, perhaps for a
separate fee (people have told me $200 from CCITT in private e-mails), or like
Henry Spencer said, perhaps writing their own version of the commands doc, or,
AT THE VERY LEAST, some kind of disclaimer saying that they can't provide this
documentation for it, but if you call/write/send $$$ to such-and-such, you
can get programming information for the AT FAX command set.  Is that so hard?

Just to reiterate - in another post, Daniel I. Rosenblatt said:

------- Begin Included Article

From: dir@lookout.it.uswc.uswest.com (Daniel I. Rosenblatt)
Subject: Re: A Telebit FAX upgrade FLAME (Was: "Re: WB Fax Upgrade")
Organization: US WEST Information Technologies
Date: Wed, 6 Jan 1993 19:46:41 GMT

Check out fax-3.2.1.tar.Z on prep.ai.mit.edu:/pub/gnu

It is a fully functioning FAX package for CLASS 2 modems.

AND ITS FREE.

AND IT WORKS. 

I've got it working on Sun, MIPS, and SCO UNIX on a 386.

------- End of Included Article

Someone has already told me that GNU NetFax 3.2.1 does NOT drive the Telebit
FAX mode properly, so this is a red herring - and Yet Another Reason Why we
need the documentation, so if things go wrong, we have a prayer in H*ll of
understanding why and possibly fixing it.

To use an (admittedly contrived) example, what if you connected to a remote
FAX machine or modem and got back something like

	+FNSF:00 00 9E 00 00 00 40 F0 90 C0 00 08 A0 40 A9 09 38

and what if GNU NetFax decided "Ohmigod, some non-standard feature I don't
comprehend, I'll give up" and croaked?

Or what about Data Bit Order negotiation (+FBOR=)?  Do these FAX software
packages automatically handle this, trying another if one fails?  I got
mail from someone who cobbled up a quick-n'-dirty C program to send a FAX out
the Telebit, and he had to change his AT+FBOR= command to AT+FBOR=0 because
setting it to "1" didn't work.  How can you know that you may have to change
the parameters your FAX software uses for this particular platform if you have
no documentation on what those commands are, what values they take, what those
values mean, and and what any return codes indicate?

It was pointed out to me that if I wanted the documentation, I should pay my
$200 and not fault Telebit for keeping the price of the upgrade down.  Fair
enough, but the official docs should be mainly of interest to the people that
are actually writing the FAX software.  I just want enough documentation to
know what the commands are and the meaning of things, not the complete
every-little-detail document.

The prosecution rests ...

--
	- Greg Earle				| Disclaimer: These are MY
	  Itinerant Sun Consultant		| opinions ONLY, not JPL's!
	  isolar!earle@elroy.JPL.NASA.GOV	| They just let me post through
	  (818) 353-8695			| their machines ...