NetNews Usenet Archive 1993 #3/NN_1993_3.iso/spool/comp/os/mswindo/apps/7572

Internet Message Format | 1993-01-27 | 2.6 KB

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From: [e-mail] (Keith Walker)
Newsgroups: comp.os.ms-windows.apps,alt.fax,comp.dcom.fax
Subject: Re: WinFAX Pro 3.0 and Class 1 & 2, what are they?
Message-ID: <[e-mail]>
Date: 26 Jan 93 15:35:33 GMT
References: <[e-mail]> <[e-mail]>
Organization: Keith's House
Lines: 36

In article <[e-mail]> [e-mail] (Keith A Marlow) writes:
>>Can somebody explain the difference between Class 1 and Class 2 faxing?
>
>If the Fax-Modem you are considering is termed "Class 1" then it will
>implement features like V42/MNP-2,3,4 error correction and
>V42bis/MNP-5 data compression inside the communication software running
>on your computer - which will most likely be a package that comes
>pre-packed with the the Fax-modem (and which might also make upgrading
>or swapping to other software difficult if you don't like that
>package!). There is an existing  "standard" implementation of "Class 1"
>control called RPI (the Rockwell Protocol Interface) but you
>have to hunt hard to find the comms packages that have it! I can only
>think of "Quicklink II Fax".

I'm sure that the designers at Rockwell love this invalid
interpretation of Class 1.  Class 1, also known as EIA/TIA-578, has
nothing to do with the RPI.  Class 1 is an "open" standard describing
one particular interface to a fax modem.  The RPI is a proprietary
interface that will allow you to activate certain features (the
V42/MNP stuff you metioned) of certain Rockwell chipsets (such as the
RC224). You cannot get a description of RPI, only an object module to
link in with your MS-DOS programs.  It is *not* cheap.  (Actually, as
with all things like this, if you are willing to spend a lot of money,
you can get the description but I was unwilling to spend the
$10,000.00 I was quoted to support two lousy modems.)

Class 1 and the RPI have nothing to do with one another other than the
fact that Rockwell has placed support for both on a chipset (RC224).

The RPI is hopefully going away simply because nobody would buy it.

--
[e-mail] | Ah, the early space program:
Keith Walker             | The moon, the planets, the stars!
                       | We were going to do *everything*!
[phone]         | Now, it's everything we can do. :-(