Path: utzoo!utgpu!news-server.csri.toronto.edu!rutgers!cbmvax!uunet!hayes!tnixon
From: tnixon@hayes.uucp
Newsgroups: comp.dcom.modems
Subject: Re: want info on fax modems for PC
Message-ID: <3819.27ce2b7c@hayes.uucp>
Date: 1 Mar 91 10:22:51 GMT
References: <44845@ut-emx.uucp>
Followup-To: comp.dcom.modems
Distribution: usa
Organization: Hayes Microcomputer Products, Norcross, GA
Lines: 78

In article <44845@ut-emx.uucp>, sanjay@ccwf.cc.utexas.edu (Sanjay
Keshava) writes: 

> What input format do the Fax modems require?  ...text, formatted text,
> bitmap?

The fax modem itself wants data in compressed Huffman-coded format 
as specified in CCITT Recommendation T.4 -- the same format that is 
used to send the image on the phone line.  The software that comes 
with most fax modems has the ability to convert from a variety of 
file formats into the T.4 image format.

> In what format do fax modems output received faxes?

The same T.4 image format referred to above.  The software oftens 
adds headers or other information to the file for its own 
convenience, but the modem itself deals with only T.4.

> How can I view received documents?

That is a function of the software provided by the modem.  
Magnification capability is important (the resolution of most 
screens is much lower than fax), as is image rotation (many people 
load documents into their machines bottom-first, which causes them 
to come through upside-down and difficult to read on a screen!)

> What are the general procedures for creating and sending a fax, and
> receiving and viewing one?

This varies with the software capability.  Most want you to direct 
the output of your word processor or other program to a file on disk 
(some will redirect it for you), then process it through a program 
(either offline, or on-the-fly, depending on the software) to 
convert it to T.4 image format.

> Are PC fax modems compatible (baud rate, encoding, etc.) with
> conventional fax machines?

Absolutely.  They'd be useless otherwise.

> What features should I look for?

That's a big question that is difficult to answer.  Again, remember 
that most of the functions are provided by the software -- the modem 
is pretty dumb.  You have to decide whether or not receiving and 
sending in the background is important to you, or whether its OK to 
set the PC up each time you want to receive a fax.  Will you be 
sending to one user at a time, or to distribution lists (I send to 
long lists on occasion, when sending press releases)?  List 
management is an important function.  Do you want to be able to 
design your own cover sheets, use different cover sheets at 
different times, or settle for whatever the software provides?  What 
file/graphic formats do you need to support?  Do you want an 
external modem or internal?  Can you afford to have the modem use up 
one of your serial COM ports, or do you want one that is memory 
mapped or otherwise interfaces in a manner that doesn't affect 
existing serial devices?  Do you want the modem to also have data 
capabilities, or is a dedicated fax modem OK (i.e., you already have 
a data modem)?  What operating system do you run -- DOS, Unix, or 
something else -- since you have to have compatible software to use 
the modem?

> Lastly, any horror/success stories?  ...recommendations?

My personal experiences are all with the AppleFax modem on a 
Macintosh, using both Apple's AppleFax software and BackFax from 
Solutions, Inc.  BackFax seems to work great.  In the PC 
environment, there is a lot to choose from.  The Hayes JT Fax 9600 
has received very good reviews in a lot of magazines, both for the 
quality of the modem itself and the software.  Hayes provides DOS 
software, but there is very good software available also for Unix 
from several different companies.

-- 
Toby Nixon, Principal Engineer    | Voice   +1-404-840-9200  Telex 151243420
Hayes Microcomputer Products Inc. | Fax     +1-404-447-0178  CIS   70271,404
P.O. Box 105203                   | UUCP uunet!hayes!tnixon  AT&T    !tnixon
Atlanta, Georgia  30348  USA      | Internet       hayes!tnixon@uunet.uu.net