Ham Radio 2000/Ham Radio 2000.iso/ham2000/fax_sstv/easyfax/easyfax.doc

Text File | 1992-01-11 | 23KB | 716 lines

                   EASY FAX instruction manual
                   ===========================


 GENERAL INFORMATION
 -------------------

 EASY FAX is a non-professional radio facsimile tool.  Completely
developed  using the Turbo C language this software  is  intended
for free exchange, any use of this software for commercial aim is
forbidden.

 Unlike  others software for facsimile reception, EASY  FAX  does
not  require  any type of interface to connect the audio  of  the
receiver  to  the  computer;  in each  case  ,  to  increase  the
sensitivity  of the system, the insertion of a signal-squarer  is
to  prefer.  To receive amplitude modulated  sub-carrier  signals
(such   as  weather-satellite  signals)  a   voltage-to-frequency
converter is required; it must be preceded by a band pass  filter
tuned on the sub-carrier frequency (usually 2400Hz or 1200Hz),the
output  of this one have to be rectified before the  introduction
into  the same converter. More detail on the  hardware  explained
later.

 The computer must be IBM 100% compatible with at least  640kbyte
of  memory, 1 hard disk, 1 Very enhanced Graphics  Array  adapter
board  (VGA), 1 RS232 serial adapter. Intel 80286,80386 or  80486
microprocessor-based  computers are prefered, especially  if  the
240  lines per minute reception is request, on the  8088/8086  or
very   slow  80286  computers  the  software  frequency   sampler
implemented  by the EASY FAX program may not allow  reception  of
higher lines per minute fax signals.
 Probably EASY FAX can run with MS-DOS 2.0 or later, in each case
an MS-DOS 3.0 or later is to be prefered.





















 INSTALLATION PROCEDURE
 ----------------------

 To run correctly, EASY FAX has to be copied into a sub-directory
of  your  hard  disk, once this operation is done,  you  have  to
decide  where is the place to put the image files, i.e.  in  what
sub-directory  or disk you want to store it. The mean to  specify
this  sub-directory  is the enviromental  variable  EF_PATH.  The
set  of EF_PATH can be done into your autoexc.bat file  including
the  line :  SET EF_PATH=[disk id:][directory path]; for  example
if you want to place your received images into the  sub-directory
\EASYFAX\IMAGES   of  disk  drive  E:,  you  must  add  in   your
autoexec.bat this line :

                         SET EF_PATH=E:\EASYFAX\IMAGE






 All  disk identifier is valid, in each case the use of a  floppy
disk  such  as A: or B: isn't a good idea, due to the  slow  data
flow  who  they can support. The lenght of the  path  name  can't
exceed  26  characters.  If  you  prefer  instead  of  the  above
operation, you can create a batch-file like this explained below:

         SET EF_PATH=E:\EASYFAX\IMAGE
         EASYFAX %1
         SET EF_PATH=

 Running  this  file  (called  for  example  EF.BAT)  instead  of
EASYFAX.EXE,  you  can  release  the  memory  occupied   by   the
enviromental variable, once the EASY FAX session is ended. The %1
parameter is useful to permit the access to the EASY FAX setup.
 Remember that the EF_PATH variable specify the default value, if
its setup is missed, the sub-directory where the EASYFAX.EXE file
is placed is assumed.

















 EASY FAX SETUP UTILITY
 ----------------------

 The  first time you run EASY FAX probably you have to  set  some
parameters  in function of your hardware; some of these  such  as
the  communications port, the interrupt handler,  the  brightness
and the contrast of video display are accessible only by mean  of
the  /S switch added in the command line; i.e. to enter in  setup
mode you have to type the command show below:

         EASYFAX /S

 After this command is done  EASY FAX show you the current  setup
and wait for changes. In detail the keys actived in this  section
are the followings:

         <F1>  = change the communications port (COM1:,COM2:,COM3
                 and COM4 are availables) the  interrupt  handler
                 is set to the conventional value  for  the  port
                 selected.

         <F2>  = change the interrupt handler (IRQ3 or IRQ4).

<Left>/<Right> = move the graphic cursor inside the gray-scale to
                 select the gray bar to modify.

        <Down> = darken  the selected bar.

          <Up> = brighten the selected bar.

         <Esc> = accept the changes for this session of  EASY FAX
                 but don't store them on disk.

       <Enter> = accept the changes and  store them on  disk  for
                 next sessions of EASY FAX.

 The  brightness  and darkness limits for each gray  bar  is  the
value  of the two bars respectively on the right and on the  left
of the bar selected.
















 HARDWARE CONNECTIONS
 --------------------

 Once  decided what's the communications port to connect  to  the
radio,  the  pins of the connector on the rear  of  computer  are
assigned as described in the table below:


            SIGNAL | DB25 PIN # | DB9 PIN # | FUNCTION
           --------+------------+-----------+----------
             GND   |   1 & 7    |     5     |  GROUND
           --------+------------+-----------+----------
             RTS   |     4      |     7     |   +12V
           --------+------------+-----------+----------
             DTR   |    20      |     4     |   -12V
           --------+------------+-----------+----------
             DSR   |     6      |     6     | AF INPUT
           --------+------------+-----------+----------


 How  you can see in the table, are indicated two columns of  pin
numbers, this is done because of the two standard connector  used
in  RS232  network, so if your computer is equiped with a  9  pin
connector  you  have  to refer to the DB9 column,  else  if  your
computer is equiped with a 25 pin connector you have to refer  to
the  DB25  column. The current sourced by the RTS  and  DTR  pins
don't  have  to  exceed 5mA, so if your  interface  needs  higher
current  you  have to provide an external power supply;  in  this
case  remember  to connect its ground to the GND  pin(s)  of  the
computer.  Many people thinks that connect a radio to a  computer
is dangerous for electrostatic discharge, i don't advise the  use
of  photocoupler  but  if you want to put it  between  the  rigs,
remember  to  unconnect the ground wire of computer by  the  some
wire of the radio (or interface), else the photocoupler  function
is  bypassed  and  void.  How discussed  at  the  begin  of  this
document, the use of a signal-squarer is advisable to improve the
sensitivity   of  the  system;  it  may  be  realized  using   an
operational amplifier used such as a Schmitt trigger with a small
voltage  hysteresis  (less than 100mV);  an  another  inexpensive
signal-squarer  may  be  done simply driving the base  of  a  NPN
bipolar  transistor  with  the AF signal via  a  current  limiter
resistor  (about 10Kohms), the emitter must be connected  to  the
GND pin, the collector instead must be connected to the DSR  pin,
a pull-up resistor(1Kohm) must connect RTS to DSR, this  solution
theorically is wrong, but i had test it on some RS232  interfaces
with good results.









 HOW TO USE EASY FAX
 -------------------

 This software was written for fun, it's not a professional  tool
for  radio  fax  reception, but it can be a good  aid  for  radio
relayers  or listeners who want to approach to the world of  slow
scan  image  transmission (meteo chart, newspaper  and  satellite
photos).

 To  start  EASY FAX in DOS environment execute  EASYFAX.EXE  (or
EF.bat if any). Once the EASY FAX logo is appeared on your  video
screen, you have to press one key to continue; after you can  see
the  "EASY  FAX main menu" appear on the top-left corner  of  the
video  screen. This main menu can be cleared or recalled via  the
<Esc>  key  (it's usually located at the top-left corner  of  the
keyboard).

 The  "EASY FAX main menu" shows the commands availables, on  the
left  of the equal sign is represented the key to be pressed  and
on  right is indicated a short form description of  the  function
associated to the key.

 Near  the bottom of the "EASY FAX main menu" is present  a  gray
box,  in this box are normally displayed : the  current  selected
lines per minute scan rate, the page wrapping option status,  the
name  of the image loaded into the video buffer and the  name  of
the setup file in use.




























 MAIN MENU FUNCTIONS
 -------------------

 <R>  (image  Reception)

 This command lets you enter into the "EASY FAX rx menu". If  you
have received another image yet, EASY FAX prompt you to answer if
you  want really continue (in that case you lost last  image)  or
return to main menu. Once you are in the rx menu the reception is
enabled and the signal received (if any) begin to build the image
starting  on the top-left corner of the video screen.  In  bottom
left  corner  the  rx menu remember you  what  are  the  function
enabled.  This  menu  is slowly cleared by the  image  that  take
shape, this to let it the longer time possible on the screen. The
sub-functions enabled are :
 <Home> (syncro start) pressing this key the computer enter  into
a  waiting  state  until the standard  syncronization  signal  is
received.
 <End> (abort syncro start) clear the above function.
 <Del>  (clear  screen) erase the entire video screen  and  video
buffer, after it redraw the "EASY FAX rx menu".
 <F1> (LPM select) pressing this function key change the line per
minute rate, the values for this selection are: 60,90,120,180 and
240 (Note  that higher lines per minute rate may be  unaccessible
on slow machines).
 <W>  (turn  page wrapping on|off) this key, if pressed, let  you
switch  on or off the capability of the program to return at  the
top-left  corner of video after the bottom-right of the  same  is
reached(if  this function is disabled the program exit  from  the
"EASY  FAX rx menu" when the image reach the bottom of the  video
screen).
 <F4> (update file ########.DAT) using this function key, you can
update the configuration file indicated(if any).
 <Left> (\\ image adjust) this key lets you straighten the  image
during reception if it's top-left to bottom right inclined.
 <Right>  (// image adjust) the same as the above  mentioned  but
for top-right to bottom-left image inclination.
 <+>  (\ fine image adjust) it's the same of <Left> but for  fine
tuning.
 <-> (/ fine image adjust) it's the same of <Right> but for  fine
tuning.
 <Esc> (return to main menu) this key,if pressed exit from the rx
menu and go back to the "EASY FAX main menu".












 <T>  (Tuning utility)

 This  key  clear the image from the video screen (not  from  the
video  buffer) and put you into the tuning tool; it's a  spectrum
analizer like display. On the top-left of the video screen  three
box itemize what's the edge of the gray scale you can move  using
the  <Left> and <Right> keys; to select the box you have  to  use
the  <Up>  and  <Down> keys, the selection is  indicated  by  the
enhancement of the line who composing the same box. How indicated
on the screen, the frequency markers are intended for  indicative
use  only, i.e. may be that the frequency indicated differs  from
the frequency really connected to the serial port, this is due to
the slowness of the computer, in each case the relation from  the
frequency indicated and the gray bar is correct. A special marker
is  also indicated on the graph, this marker shows you the  lower
limit that guarantee the horizontal dot resolution, the  position
of  this marker changes on the 240 LPM scan rate. Tune the  black
and  white bars respectively near the lower and higher  edges  of
the shapes drawn by the signal received.



 <O>  (set Origin)

 Using  this key, the "EASY FAX help" window appears  instead  of
the  main menu; this window tells what you have to do. To  remove
the  help window you have to press any of <Left>,<Right>,<Up>  or
<Down>  key or, if present, move your mouse on the desk; now  you
can  move the pointer (the small cross appeared on the centre  of
the  screen)  using the above keys or the mouse; if you  use  the
keys  remember that the <Scroll Lock> key sets the speed  of  the
pointer  movements, in detail if the Scroll Lock light is  turned
on the speed is one pixel at a time otherwise is eight pixels  at
a time. The pointer indicates the pixel who will become the  top-
left corner of the video screen, to do that press the <Enter> key
otherwise, to abort this function press the <Esc> key. For  mouse
users the left mouse button is the same of <Enter> and the  right
mouse button is the same of <Esc>.


 <H>  (Horizontal image mirror)

 This function is useful in many facsimile signals who build  the
images  from right to left instead of the standard left to  right
image  transmission. Once you pressed this key the image  on  the
screen is re-painted.


 <V>  (Vertical image mirror)

 This  function re-paint the image up side down, it's useful  for
polar weather satellite images that represent the earth depending
on their path (if North to South or vice versa).


 <N>  (Negate (reverse) color)

 This key, if pressed reverse the gray shades i.e. black  becomes
white  and  vice versa etc. This is useful, for example,  if  you
mistake the sideband during the reception of an SSB image.


 <Z>  (Zoom selected zone)

 Using  this key, like in the "set origin", the "EASY  FAX  help"
appears  instead of the main menu; the operation are the same  as
such  in the set origin function; the difference is the  pointer,
who is a 320 by 240 pixels box; once you pressed the <Enter>  key
or  clicked the left mouse button, the part of image  inside  the
box is magnified by 2, otherwise you can press <Esc> or click the
right  mouse  button to shut down this function.  Note  that  the
magnified   image  maintain  the  vertical  resolution  and   the
horizontal  resolution  is re-computed via the mean  of  adiacent
pixels.



 <S>  (Save image)

 Once you pressed this key, EASY FAX ask you the name to give  at
the  image to be saved, if you answer with <Esc> the function  is
aborted  and nothing is done. The name may be 8 characters  long,
and must be at least 1 character, all alphanumeric keys are valid
characters,  the extension is by default ".FAX" and the  path  is
set  by the EF_PATH enviromental variable or the later  discussed
<C> command. To accept the name and save the image press <Enter>.


 <L>  (Load image/List image)

 This key puts the program into the "EASY FAX image loader"; here
you  can load one of the listed images files simply pressing  the
respective  function  key  associated to,  if  the  sub-directory
contains other images you have to press the <F10> key to  display
them.  The small gray box at the bottom of the image loader  show
the  current  sub-directory  and the name of  the  current  image
loaded into the video buffer. If you want to shut down the  image
loader without loading any image, press the <Esc> key.


 <P>  (create 1280x960pixels Pxc image)

 Once you pressed this key, the program ask you the name to  give
at the ZSoft .PCX file to be created. The keys and procedures are
the same as in the "Save image" function except for the extension
(naturally  is  .PCX  !!). This function is  useful  to  transfer
images to high level drawing programs such as PaintBrush VI  plus
by ZSoft, these programs can clear the images from spots produced
by  weak  signals  received and can print the  image  using  very
powerful functions.
 <C>  (Change current path for images)

 This function lets you free to change the current path name i.e.
the  place where EASY FAX stores and load the images.  The  maxim
length is 26 characters, all alphanumeric keys are valid here  in
addition the <\> and <:> characters are available; the <Esc>  key
shut  down the function and leave the path unchanged,  to  accept
the  new  path name press the <Enter> key; root  directories  are
invalid  and  floppy  disk identifier such as A: or  B:  are  not
advisable.  An  invalid path name produces an error  message  and
assumes the sub-directory where the EASY FAX program is placed as
the current path.


 <U>  (Up load setup)

 After you recall this function the program enter into the  "EASY
FAX setup loader"; it's like the image loader but it show you the
list  of  setups availables. Into the gray box at the  bottom  is
indicated the current setup (if any).


 <W> (Write new setup)

 This  function write the current settings into a .DAT file.  The
procedure  is the same as the (Save image) function but the  path
is always the sub-directory where the EASY FAX program stays.


 <Q> (Quit program)

 Once  you  pressed this key, the program ask if you  are  really
sure  and  if you answer <Y> the program exits otherwise  if  you
press <N> it return to main menu.





















 THANKS
 ------

 I wish to be thankful for the help gived to me by the people who
had  tested the program in its first release. Special  thanks  to
TRAVAGLINO Mario (IK1GKJ) for the consultancy on Turbo C and 8086
assembly  languges  and  BOZZOLA  Angelo  (IK1MSL)  for   program
testing and delivery.





 SOMETHINGS ABOUT THE PROGRAM
 ----------------------------

 I began the writing of EASY FAX on March 1991, first it was just
a  bet  with  myself, to be able to  receive  a  facsimile  image
without  any interface; after, many days later, i  have  realized
that  the  program  was  efficient and i have  decided  to  do  a
complete tool for facsimile reception. This was my first  program
written  in C language and it was completed part-time  along  the
rest of 1991, so it is not surely optimized. I hope you will have
fun with it. I wish you all the best in facsimile reception,  and
if  you  are  a radio relayer i hope to met you on  the  air,  my
callsign is IK1IZA.


       Best regards

              PORZIO Massimo



























                         A D D E N D U M
                         ===============


12-20-1991
----------

 Version 1.08

 The escape key into the setup enviroment now run correctly.


01-04-1992
----------

 Version 1.09

 Some radio relayers on the RBBS network indicates that EASY  FAX
don't run correctly on 386/486 machines. This version solves  the
problem due to the timer/counter chip installed on that machines.
The  frequency  counter  routine is  now  re-written  for  better
reception and a bus-clock frequency counter is added at the start
of  program.  Some 286 compatible such as Commodore  Pc-30  can't
still execute correctly EASY FAX ,i don't know the  timer/counter
chip used on it, so i can do nothing!!.
 When the EASY FAX logo appears, a new message can pop up in  the
centre of the screen, this message warning you that the  selected
communication  port  is  not ready(may be it's  absent  or  wrong
addressed),in  that  case you can use EASY FAX for  viewing  pre-
recorded images but you can't receive any others of them.

Many thanks to IK1MSL BOZZOLA Angelo,who let me use his new 80386
based computer to debug this software.



















01-11-1992
----------

 Version 1.10

 I  written  this update to give to EASY FAX  the  capability  to
create  640x480pixel  HFFAX  image files; this  function  is  now
available  in the main menu pressing the <F> key and  typing  the
name of the file. The HFFAX files compatibility lets you free  to
use  all the softwares wrote to this files, such as FAXCOLOR  the
color  images builder; at first  i think to write  an  equivalent
software  to the EASY FAX format but the file created became  too
large; so, at last, i preferred this way, in each case if someone
want  to  write  software to manipulate the EASY  FAX  files  the
structure  is  explained below. At the same time i  re-wrote  the
load  and  save  functions, so now they  are  much  faster.  I've
removed also some little "bugs".


EASY FAX file structure
-----------------------
 The  first  three  bytes represent the keyword  "FAX",  used  to
identify  the  file; the next bytes represent the  image  shapes,
each  byte  represent two pixels, the  least  significant  nibble
represent  the  pixel  on the odd lines  (1,3,5,7...),  the  most
significant nibble instead represent the pixel on the even  lines
(2,4,6,8...); the lines are represented starting on the top (line
1) and ending at the bottom of image (line 960); each line is 640
bytes long, the 1280 pixels resolution is obtained by the average
value of two consecutive pixels; the nibble value 0 is the  color
white and the value 15 represent the color black.
























 TRADEMARK & COPYRIGHT ACKNOWLEDGEMENTS
 --------------------------------------


 Turbo C is a trademark of Borland International,Inc.


 IBM  and VGA are trademarks of International  Business  Machines
Corp.


 Intel,8086,8088,80286,80386  and 80486 are trademarks  of  Intel
Corp.


 MS-DOS is a trademark of Microsoft Corp.


 PaintBrush VI plus and ZSoft are trademarks of Zsoft Corp.


 Commodore Pc-30 is a trademark of Commodore Business Machines.


 HFFAX  is a copyrighted software (c)1987-88-89-90 John E.  Hoot,
Software Systems Consulting.

 FAXCOLOR  is  a  copyrighted  software  (c)  1991   IW1CIX-I1EPJ
licensed to NUOVA ELETTRONICA.

 NUOVA ELETTRONICA is one of the most popular electronic magazine
in  Italy  that  delivers Kits such as LX.1004  or  LX.1049  100%
compatible  with  the EASY FAX communications  port  for  Weather
Satellite reception.