home
***
CD-ROM
|
disk
|
FTP
|
other
***
search
/
Ham Radio 2000 #2
/
Ham Radio 2000 - Volume 2.iso
/
HAMV2
/
FAX_SSTV
/
MSCAN211
/
MAN210E.DOC
< prev
next >
Wrap
Text File
|
1996-11-25
|
67KB
|
1,703 lines
MANUAL MSCAN 2.10
TABLE OF CONTENTS
1 INSTALLATION
1.1 Installing the MSCAN software
1.2 Computing the xtal calibration factor
2 OPERATION
2.1 Screen layout
2.2 Selecting the program mode
2.3 Loading and saving pictures
2.3.1 Changing the path
2.3.2 Loading a picture from disk
2.3.3 Loading a picture from the auto directory
2.3.4 Loading a picture from memory
2.3.5 Loading a standard image
2.3.6 Loading a picture from a video digitizer
2.3.7 Saving a picture to disk
2.3.8 Saving a picture to memory
2.4 Text editor
2.5 Receiving and transmitting pictures
2.5.1 Receiving pictures in SSTV modes
2.5.2 Transmitting pictures in SSTV modes
2.5.3 Receiving pictures in Fax modes
2.5.4 Transmitting pictures in Fax modes
2.6 Processing pictures with the toolkit
2.7 Managing the spectrum
2.8 Exiting the program
APPENDIX I - INTERFACES
A Interface comparison chart
B Installation of each interface
1. OPAMP
2. Microscan RX
3. PC speaker
4. TxD pin
5. Ad Lib
6. Multiscan
7. EasyFax
8. ViewPort VGA
9. Miniscan
APPENDIX II - SUPPORTED VIDEO DIGITIZERS
A Iris
B Video Blaster
C ComputerEyes/RT
APPENDIX III - TROUBLESHOOTING
APPENDIX IV - MODE DESCRIPTIONS
A SSTV
B Fax
APPENDIX V - AGENTS AND CONTACTS
MSCAN 2.1x (c) Copyright 1996 CombiTech - Holland
CombiTech,
P.O. Box 507,
3235 ZG Rockanje,
The Netherlands.
Tel/Fax: +31 181 404252
B.B.S. : +31 181 404513
Email: combitech@pi.net
http://www.pi.net/~ctech
Ad Lib is a registered trademark of Ad Lib, Inc. The Graphics Interchange
Format(c) is the Copyright property of Compuserve Incorporated. GIF(sm) is a
Service Mark Property of Compuserve Incorporated. IBM is a registered
trademark of International Business Machines Corporation. Sound Blaster and
Video Blaster are registered trademarks of Creative Technology Ltd. All other
products are trademarks or registered trademarks of their respective owners.
1 INSTALLATION
MSCAN is a program for receiving and transmitting SSTV and Fax images. For
convenient operation, MSCAN requires an IBM-compatible personal computer (PC)
with at least an 80286 processor, SVGA video capable of displaying in 16.7
million colours (true colour) and a mouse. MSCAN supports various modems, from
the simple Hamcomm interface to the advanced Multiscan modem. A short
description of these modems and a comparison chart can be found in Appendix I.
MSCAN is a unique program. No other program offers the multitude of
multitasking possibilities you will find in MSCAN. While you are transmitting
or receiving a picture, MSCAN enables you to load another picture, or digitize
it, and overlay it with text. To make all of this possible, MSCAN uses many of
the advanced (often not used) features your computer, graphics adapter and
mouse have to offer. It is therefore absolutely necessary that these parts
have a high degree of compatiblity and that MSCAN will not be influenced by
any other program which would be present in memory (so called resident
programs).
MSCAN consists of two files:
MSCAN.EXE - the main program
MSCAN.CNF - the configuration and registration file.
1.1 Installing the MSCAN software
The MSCAN software is supplied on floppy disk which should be copied to the
computer hard disk before use. At the DOS prompt type :
MD \MSCAN
CD \MSCAN
Now copy the software from the distribution disk to this new directory, e.g.:
XCOPY A:*.* /s
Before the software can be used it must first be configured.
To enter the calibration menu type:
MSCAN /C followed by a <Enter>.
A number of questions will be asked in sequence, with each entry the current
status is reported (...). If you do not want to change a parameter a simple
<Enter> is sufficient.
SVGA chipset
Select the chipset which is present on your video card. If MSCAN does not
support your chipset select VESA, this will work most of the times. Some video
cards are very slow in VESA mode, selecting VESA/fast will cure this problem
but some cards may not work properly in this mode.
When VESA is selected, the following question will be asked:
VESA mode
Select standard to begin with. If you do not get the correct image on your
display (e.g. the menu is at the top and not at the bottom of the screen) then
try starting MSCAN again with the hybrid#1 and hybrid#2 settings. It is
possible that your video card requires a VESA driver to be loaded in order to
be VESA compatible.
RX interface
Select the interface you want to use for decoding SSTV & Fax signals.
TX interface
Depending on which RX interface you have selected, you may now have a choice
of which interface you want to use for generating signals.
For a short description of the available interfaces see Appendix I. Some
interfaces need to be calibrated, if so this will also be explained in
Appendix I.
Spectrum calibration factor low
Spectrum calibration factor high
Some RX interfaces require calibrating. The outcome of this calibration is
stored in two values: the spectrum calibration factor low and high. If you
have a previous version of MSCAN, enter the same values here which are
displayed in the configuration menu of your previous version. If you bought an
assembled Multiscan it will already be calibrated, and you will have received
the calibration factors on paper. Fill them in here.
COM port or LPT port
Depending on which RX interfaces you have selected, you will now be prompted
for the port to which this interface is connected.
COM port IRQ nr
Depending on which RX interface you have selected, you will now be prompted
for the IRQ number of the selected COM port. The text 'standard' will mark the
IRQ number that is normally associated to this port.
RX display sequence
TX display sequence
These questions allow you to determine the default receive and transmit screen
settings in the SSTV modes. You can always change these settings afterwards in
the program itself.
Crystal calibration factor
Both new SSTV and Fax modes rely heavily on synchronism between transmitter
and receiver, for this the PC has to be able to precisely set timing.
Therefore you will have to calibrate the PC. The computed correction factor
(see 'Computing the calibration factor') can be entered here. If you have
already computed this factor for a previous version, simply enter the old
factor here.
Header text
Just before a picture is transmitted, a header will be placed at the top of
it. This header contains your callsign at the left, and the version number of
MSCAN at the right. The space in between can be filled with the 'header text'
(due to limited space not available in B&W and Wraase modes).
Call to be transmitted
In the shareware version of MSCAN you can enter your callsign here.
Note:
If a memory manager like QEMM, EMM386 or 386MAX has been installed in your
computer, then disable it first. On some PCs memory managers can greatly
influence timing. This can cause MSCAN to function incorrect or even not at
all! You can disable the memory manager by placing the text 'REM ' in front of
where the command is placed in your AUTOEXEC.BAT or CONFIG.SYS file. Then
restart your computer and run MSCAN and check its proper functioning. If all
is ok, then enable the memory manager, reboot your system and run MSCAN again.
If you detect any problems, or a degraded picture quality, then you cannot use
this memory manager while running MSCAN.
1.2 Computing the xtal calibration factor
Precise timing is vital for especially the new SSTV and Fax modes. A slight
deviation in the crystal frequency of the PC will result in bad
synchronization (picture skew) when receiving pictures. If you detect this
picture skew when receiving SSTV or Fax signals, first confirm it by receiving
a picture of a 'commercial' Fax station (i.e. calibrated station). If the
picture is still skewed, the crystal in your PC will have a slight deviation
(which is absolutely normal!). MSCAN uses the xtal calibration factor to
remember the deviation in this crystal. Calibration is easy:
1) Switch the program to New SSTV mode (SYN or VIS setting) or Fax mode
by clicking on the program mode indicator.
2) Receive a picture from a calibrated station.
3) Without changing the mode, click the PARAM menu button and click again
on CALIB. You will now be prompted to mark the top of the picture.
Move your mouse pointer to e.g. the top left corner of the picture and
click the left mouse button. Now move your mouse pointer to the bottom
left corner of the picture, doing this you will draw a line parallel
to the picture. Now click again the left mouse button. MSCAN now
automatically calculates the xtal calibration factor and stores it in
the configuration file.
Beware that commercial stations can transmit skewed pictures, simply because
someone placed the chart askew in the Fax machine! A good alternative is to
use a timepulse station (look around 10 MHz) which will transmit a bleep e.g.
every second. These bleeps appear as small lines on your screen. When your
calibration is ok, these lines must appear directly under each other.
2 OPERATION
To start the main program type
MSCAN followed by <Enter>.
The program will enter the default mode which was defined during
configuration.
2.1 Screen layout
In the SSTV modes most of the screen is filled with two screens, numbered 1
(left) and 2 (right). These screens are used to display incoming and/or
outgoing images. Below this the 14 memories are displayed. Since Fax modes
require display of high-resolution pictures, here only one big screen is
visible.
At the bottom of the screen you can see the console, which is made up of the
spectrum, the indicators and the menu buttons.
The spectrum shows the in- or outgoing audiosignal. The spectrum contains a
sync-indicator. When a correct synchronization is established this indicator
lights up. In SSTV modes you can see three markers at the bottom of the
spectrum, these mark the frequencies (from left-to-right) 1200, 1500 and 2300
Hz. In Fax modes the 1200 Hz marker is omitted since it has no function. The
other two markers either mark 1500 and 2300 Hz for 800 Hz shift or 1750 and
2050 Hz for a 300 Hz shift.
In the console of MSCAN you can find both (menu) buttons and indicators. Menu
buttons are visible in the lower part of the console and make up the menu.
Indicators can have a display function only, or can have both a display and
button function. In the latter case clicking an indicator, using your left
mouse button, will activate a corresponding function, or will select a new
setting. Some indicators have more than one function, by repeatedly clicking
on the indicator other functions or settings are shown. A function or setting
will become active when the indicator is not changed for one second, or when
another indicator is clicked. The right (and middle) mousebutton have an
escape function and are used to leave a (sub)menu.
2.2 Selecting the program mode
┌────────┐ ┌────────┐ ┌────────┐ ┌────────┐ ┌────────┐
│B&W SSTV│->│ WRAASE │->│NEW SSTV│->│B&W FAX │->│COL FAX │
└────────┘ └────────┘ └────────┘ └────────┘ └────────┘
To the right of the spectrum you can find the program mode indicator, which
shows the current program mode (like SSTV or Fax). Clicking on it selects
another program mode.
2.3 Loading and saving pictures
You can load a picture from disk, from the auto directory or from one of 14
memories (which are in fact stored on disk). MSCAN will load pictures in GIF
and JPEG format. Because of the high data compression pictures will always be
saved in JPEG format. Pictures can be loaded and saved at all times, even when
receiving or transmitting another picture. A picture can be loaded into the
entire screen or just to a part of it (called a box). In the same way the
entire screen or just a part of it can be saved. MSCAN will automatically
scale pictures to fit in a screen or box. Also, when loading to screen 1 or 2,
the aspect ratio (height/width) of the picture will be slightly (up to 25%)
adjusted to ensure optimal fit. In B&W modes picture colours will be
translated to grey shades.
2.3.1 Changing the path
╔════════╗ ╔════════╗
║PICTURE ║ -> ║ PATH ║
╚════════╝ ╚════════╝
Here you can change the path to the picture directory. This path is used when
loading or saving a picture from/to disk. After clicking PATH a cursor will be
visible, you can now enter the new path, e.g. 'a:' to read a picture from disk
a:, or you can press <Enter> again (or left mouse button) to get a visual
presentation of directories. You can locate the desired directory by clicking
on the presented buttons. Each time you click a directory the new
subdirectories (if any) will be shown. Clicking on the '..' button will place
you one directory back. If you have found the desired directory press the OK
indicator to accept, or press your right mousebutton to abort.
Note:
The current directory will be retained as the default directory even when you
return to the program the next time. This process of retaining the 'last used'
selection applies in other parts of the program (e.g. picture modes).
2.3.2 Loading a picture from disk
╔════════╗ ╔════════╗ ╔════════╗
║PICTURE ║ -> ║DISKLOAD║ -> ║ SCREEN ║
╚════════╝ ╚════════╝ ╚════════╝
╔════════╗
║ BOX ║
╚════════╝
╔════════╗
║ MULTI ║
╚════════╝
╔════════╗
║ DELETE ║
╚════════╝
╔════════╗
║ NEXT ║
╚════════╝
Depending on the mode you are in, you will be able to select SCREEN 1 or
SCREEN 2, or only one SCREEN. If you do not want the picture to fill the
entire screen but just a portion of it, select BOX. Press the left mouse
button to select the top left corner of the box, then drag the box to size and
press again the left mouse button. The picture will be loaded and fits within
the selected box size.
After your selection a cursor will appear: you can now enter the name of the
picture to be loaded, or press <Enter> or left mousebutton and pick a file
from the directory. Use the ^ and v buttons to show more entries.
If you want to load multiple pictures, select MULTI. In SSTV modes MSCAN will
now load pictures to screens 1 and 2 alternately. When transmitting, picture
load is synchronized with picture transmission. When both screens are selected
for transmission, this feature enables you to transmit several picture in a
row. Pictures are loaded alphabetically, starting with the picture you
selected.
In Fax modes a collection of small pictures will be showed across the screen.
Press the DELETE button if you want to delete a picture. If you have loaded a
picture previously and not leaved the picture menu, the name of this picture
will be showed now. You can use this name, or enter a new one, or press
<Enter> or left mousebutton to pick a picture from the directory. Use the ^
and v buttons to show more entries.
Loading a sequence of images in alphabetical order is easy using the NEXT
button. First load a picture like you are used to. Now click on the NEXT
button and MSCAN will load the next picture in the same screen or box you just
selected. For easy deleting you can alternate the NEXT and DELETE commands.
2.3.3 Loading a picture from the auto directory
╔════════╗ ╔════════╗ ╔════════╗
║PICTURE ║ -> ║AUTOLOAD║ -> ║ SCREEN ║
╚════════╝ ╚════════╝ ╚════════╝
╔════════╗
║ BOX ║
╚════════╝
╔════════╗
║TRANSBOX║
╚════════╝
╔════════╗
║ MULTI ║
╚════════╝
╔════════╗
║ DELETE ║
╚════════╝
╔════════╗
║ NEXT ║
╚════════╝
This works exactly the same as loading a picture from disk, only the picture
is not loaded from the picture directory (see configuration menu) but from the
auto directory. This is the directory where pictures are stored that are
received in the SSTV or Fax auto mode.
The TRANSBOX button will load a picture in a box, but will not place pixels
with a intensity level (luminance) below 1.2% (which are in effect black
pixels). This simple command offers many possibilities. You can now for
example use some external program to create a nice text or drawing, import it
in MSCAN and use the transbox command to place it on any picture. Or you can
fill the black characters of MSCAN with parts of a picture. The possibilities
are endless and can only be discovered by experimenting.
Tip:
You can copy memory files to the auto directory to use them for the transbox
option. Rename them for easy reference.
2.3.4 Loading a picture from memory
╔════════╗ ╔════════╗ ╔════════╗
║PICTURE ║ -> ║MEMREAD ║ -> ║ SCREEN ║
╚════════╝ ╚════════╝ ╚════════╝
╔════════╗
║ BOX ║
╚════════╝
╔════════╗
║TRANSBOX║
╚════════╝
Pictures which are stored in memory are in fact stored on disk in a special
format. This format enables the pictures to be loaded and saved very fast and
without loss of any information due as a result of compression.
The procedure to load a picture from memory is almost the same as loading a
picture from disk. The only difference is that you do not have to enter a
name, but immediately can pick a memory from the directory.
╔════════╗
║SHOWMEMS║
╚════════╝
In SSTV modes you can see 14 little boxes in the lower part of the screen.
These boxes display the contents of all 14 memories. To (re)load these boxes
with the contents of the memories click the menu button SHOWMEMS.
2.3.5 Loading a standard image
╔════════╗ ╔════════╗ ╔════════╗
║PICTURE ║ -> ║ IMAGE ║ -> ║ SCREEN ║
╚════════╝ ╚════════╝ ╚════════╝
A number of images are available in MSCAN. You can use these images for
testing or just for a background. Depending on the mode you are in, select
SCREEN 1 or SCREEN 2, or only SCREEN and then pick the desired image from the
directory. There is one special image called SPECTRUM. Choosing this image
will copy the current spectrum to the selected screen. You can use this to
show your opposite station his transmitted audio spectrum.
2.3.6 Loading a picture from a video digitizer
╔════════╗ ╔════════╗
║DIGITIZE║ -> ║ SCREEN ║
╚════════╝ ╚════════╝
╔════════╗
║ BOX ║
╚════════╝
╔════════╗
║ MULTI ║
╚════════╝
╔════════╗
║ INPUT ║
╚════════╝
╔════════╗
║SETTINGS║
╚════════╝
╔════════╗
║ DELAY ║
╚════════╝
One of the unique features of MSCAN is that you are able to digitize video
images just as easy as loading pictures from disk, even when receiving or
transmitting a picture! To be able to do this you must have one of the
supported digitizers installed in your PC: the Iris, ComputerEyes/RT, Video
Blaster, Video Blaster SE, Video Blaster FS200 or Video Blaster SE100. See
Appendix II for more information about these digitizers.
The procedure to digitize a picture is almost the same as loading a picture
from disk. Just select the desired screen or box and the picture will be
digitized and loaded. Clicking DELAY before selecting the screen will give you
a 10 second countdown before the digitize command is executed. Use INPUT to
select the desired video input. The MULTI command works the same as that when
loading a picture from disk. The Fax modes have no multi command available for
digitizing.
Clicking SETTINGS will present a menu for changing the brightness, contrast,
hue and saturation settings of your digitizer. Select which setting you want
to change, and click on - LESS or + MORE to change it. DEFAULT will change to
setting to its default value. When ready click OK to accept.
2.3.7 Saving a picture to disk
╔════════╗ ╔════════╗ ╔════════╗
║PICTURE ║ -> ║DISKSAVE║ -> ║ SCREEN ║
╚════════╝ ╚════════╝ ╚════════╝
╔════════╗
║ BOX ║
╚════════╝
Depending on the mode you are in, you will be able to select SCREEN 1 or
SCREEN 2, or only one SCREEN. If you do not want to save the entire screen but
just a part of it, select BOX. Press the left mouse button to select the top
left corner of the box, then drag the box to size and press again the left
mouse button. After your selection a cursor will appear: you can now enter the
name of the picture to be saved. If a file with this name already exists, you
will be asked if it is ok to overwrite this file. Select OVERWR if you want
to, or press AGAIN if you want to enter a different name. The picture will now
be saved to disk.
2.3.8 Saving a picture to memory
╔════════╗ ╔════════╗ ╔════════╗
║PICTURE ║ -> ║MEMWRITE║ -> ║ SCREEN ║
╚════════╝ ╚════════╝ ╚════════╝
╔════════╗
║ BOX ║
╚════════╝
╔════════╗
║DISPLAY ║
╚════════╝
The procedure to save a picture to memory is almost the same as saving a
picture to disk. The only difference is that you do not have to enter a name,
but immediately can pick a memory from the directory.
By clicking on the DISPLAY button, the complete image on your monitor will be
saved to memory.
2.4 Text editor
MSCAN has a built-in text editor which can be used even while receiving or
transmitting a picture! Simply type a character on your keyboard and it will
be placed at the position which is marked by the text cursor. You can move the
cursor around with the cursor keys on the keyboard. The cursor will disappear
if during 5 seconds no character has been typed. Pressing a key will make the
cursor visible again. The next keys also control the position of the cursor:
<Home> moves the cursor to the top-left corner of the screen
<End> moves the cursor to the bottom-right corner of the screen
<Ctrl><>> moves cursor to the right of the screen
<Ctrl><<> moves cursor to the left of the screen
<Backspace> moves the cursor one position to the left and erases that
position
<Del> clears screen and moves the cursor to the top-left corner of
the screen
<Tab> only for SSTV modes: moves the cursor to the other screen
You can control the character's size and colour by clicking on the fontsize
and -colour indicators.
┌─┐ ┌─┐ ┌─┐ ┌─┐ ┌─┐ ┌─┐ ┌─┐ ┌─┐
│T│->│S│->│M│->│L│->│T│->│S│->│M│->│L│
└─┘ └─┘ └─┘ └─┘ └─┘ └─┘ └─┘ └─┘
The fontsize indicator shows which size is selected: Tiny, Small, Medium or
Large. If the indicator is blue the characters will show transparent on the
screen, if the indicator is black the characters will erase the background.
┌─┐ ┌─┐ ┌─┐ ┌─┐ ┌─┐
│C│->│C│->│C│->│C│->│C│
└─┘ └─┘ └─┘ └─┘ └─┘
│ │ │ │ │
│ │ │ │ └ blue
│ │ │ └───── green light grey
│ │ └────────── red dark grey
│ └─────────────── black black
└──────────────────── white white
The fontcolour indicator shows the colour of the characters, or the greyshade
when in b&w modes.
2.5 Receiving and transmitting pictures
MSCAN will be in RX mode after startup. Click on the program mode indicator to
select the mode which you want to use to receive or transmit pictures.
2.5.1 Receiving pictures in SSTV modes
Click on the mode indicator, which is to the right of the program indicator,
to select the desired SSTV mode. The <F5> key will do the same.
B&W SSTV:
┌───┐ ┌───┐ ┌───┐ ┌───┐
│7.2│->│ 8 │->│16 │->│32 │
└───┘ └───┘ └───┘ └───┘
Wraase SSTV:
┌──┐ ┌──┐ ┌──┐
│24│->│48│->│96│
└──┘ └──┘ └──┘
New SSTV:
┌──┐ ┌──┐ ┌──┐ ┌──┐ ┌──┐ ┌───┐
│M1│->│M2│->│S1│->│S2│->│DX│->│R72│
└──┘ └──┘ └──┘ └──┘ └──┘ └───┘
When (in New SSTV mode) MSCAN receives a valid VIS code at the start of a
picture, it will automatically select the corresponding mode. This is reported
in the message indicator with e.g. the text 'VIS -> M1'. Previous versions of
MSCAN and the program JV-FAX both have faulty scottie modes due to
misinterpretation of its specifications. MSCAN auto detects which
implementation it receives: the correct or faulty one. The faulty scottie mode
is indicated by a ' sign in the mode indicator. Ofcourse MSCAN transmits in
the correct scottie modes.
Select the screen that you wish to use to display the received pictures, by
clicking on the display sequence indicator. You can find this indicator to the
right of the large message indicator. It has four settings:
┌──┐ ┌──┐ ┌──┐ ┌──┐
│1X│->│X2│->│12│->│XX│
└──┘ └──┘ └──┘ └──┘
1X display pictures on screen 1 (left)
X2 display pictures on screen 2 (right)
12 display pictures alternating on both screens
XX pictures are not displayed, reception is off
If the display sequence is changed from e.g. 1X to X2, MSCAN will continue to
receive on screen #1 until the start of a next picture is detected. If you
want MSCAN to immediately switch to the other screen, and there wait for a new
picture, the first select XX and then the new setting.
Incoming SSTV signals will now be displayed fully automatic on the selected
screen(s), leaving MSCAN available for other tasks. Should manual control of
reception be required, you can use the indicator to the left of the message
indicator and the menu button PARAM. The indicator has multiple functions,
depending on the SSTV mode. Each function can be selected by clicking one or
more times on the indicator.
In B&W and New SSTV modes:
┌───┐ ┌───┐
│TOP│->│CLS│
└───┘ └───┘
In Wraase SSTV mode:
┌───┐ ┌───┐ ┌───┐
│RGB│->│TOP│->│CLS│
└───┘ └───┘ └───┘
RGB only available in Wraase mode: kicks r-g-b sequence one colour back
(changes the colour of the receiving picture)
TOP start reception at the top of the screen, pressing both the <Ctrl> and
<Home> keys has the same effect
CLS does the same and also clears the screen
The New SSTV mode has an extra indicator, which is positioned to the right of
the mode indicator. It can be changed by clicking on it, or pressing the <F6>
key.
┌───┐ ┌───┐ ┌───┐
│VIS│->│LIN│->│SYN│
└───┘ └───┘ └───┘
The default setting is VIS, which means the reception of a picture is started
after receiving a valid VIS code. In SYNchronous mode reception will start of
receiving a frame startpulse (or VIS code). In both modes reception will be
fully synchronous and it will continue until the next startpulse is received.
In LINe mode every line is written after receiving a linesync pulse, just like
in B&W SSTV modes. This mode is more sensitive to noise but can be useful in
the next cases:
1) If the receiving signal is not crystal-controlled (like from a
taperecorder) synchrone mode will not work.
2) If a startpulse is not received ok the receiving picture can be shifted
to the left or to the right. You can position the picture correctly by
selecting line mode for a second or two to achieve line synchronization.
If necessary slightly adjust the receiver frequency while watching the
incoming picture and the sync indicator in the spectrum. When correct
synchronization is achieved switch back to synchrone mode.
╔═══════╗
║ PARAM ║
╚═══════╝
The param menu button's functions also depend on the selected SSTV mode. In
both the B&W and Wraase SSTV modes clicking the param button toggles between
manual and autosync mode. The manual mode is default. In this mode every line
is written after reception of a linesync pulse, and every image is started
after reception of the framesync pulse. If signals are very noisy and thus no
synchronization is achieved, selecting the autosync mode will make reception
less sensitive to noise. By looking 'intelligent' to the synchronization of
the SSTV signal, display of received images will improve, which is especially
helpful in the Wraase colour SSTV mode to prevent coloursync hickups. This
mode however only works when the transmitting stations have correct timing.
In the New SSTV mode clicking the param menu button will select another menu.
╔════════╗ ╔════════╗
║ PARAM ║ -> ║ <LEFT ║
╚════════╝ ╚════════╝
╔════════╗
║ >RIGHT ║
╚════════╝
╔════════╗
║ RGB ║
╚════════╝
╔════════╗
║ CALIB ║
╚════════╝
╔════════╗
║ AUTO ║
╚════════╝
Using the <LEFT and >RIGHT menu buttons you can move the reception of a picture
to the left or right, this will only work in VIS or SYN mode. Clicking RGB
will change the colour sequence.
The CALIB button is used when computing the xtal calibration factor.
The AUTO command activates the auto mode. In this mode MSCAN automatically
starts reception in both screens and saves the pictures in the auto directory
afterwards, using the filename mmddhhmm (month|day|hour|minute).
2.5.2 Transmitting pictures in SSTV modes
Click on the mode indicator, which is to the right of the program indicator,
or use <F5> to select the desired SSTV mode.
Select the screen that you want to transmit by clicking on the tx display
sequence indicator. You can find this indicator to the right of the rx display
sequence indicator. It has three settings:
┌──┐ ┌──┐ ┌──┐
│X2│->│12│->│1X│
└──┘ └──┘ └──┘
X2 use screen 2 (right) for transmisson
12 use both screens alternating for transmission
1X use screen 1 (left) for transmission
Now click on the RX/TX indicator to start the transmission, or use the <F9>
key. The transmission will stop automatically at the end of the picture
(indicated by the message 'auto stop'). By clicking twice on the RX/TX
indicator transmission will be continuous. The picture(s) will be transmitted
fully automatic, leaving MSCAN available for other tasks such as preparing the
next picture or adding text to the picture. Click on the RX/TX indicator until
it shows RX if you want to abort the transmission.
2.5.3 Receiving pictures in Fax modes
To fully understand the operation of some functions in the Fax modes, first
the terms 'scrolling' and 'endmarker' will be explained.
Scrolling
To be able to display long Fax pictures which can not be displayed on the
standard full screen size, MSCAN uses scrolling (vertical movement) of a
picture, which enables the rest of the picture to be shown. This scrolling is
done mostly automatic. Only when the cursor is visible, no scrolling will take
place (unless the cursor itself is moved).
The endmarker
The endmarker is used to mark the lower border of the current picture. The
endmarker works mostly automatic. When a Fax image is received and reception
is stopped (in auto mode this is done automatically) the endmarker will be
placed at the last received line, the same is done after for example a picture
is loaded from disk. Processes like transmitting or saving use the endmarker
to determine the end of a picture. The endmarker is displayed as a black &
white chequered line.
Click on the mode indicator, which is to the right of the program indicator,
or use the <F5> key to select the desired Fax mode for reception.
In B&W Fax:
┌─────┐ ┌─────┐ ┌─────┐ ┌─────┐ ┌─────┐
│ 120 │->│ 180 │->│ 240 │->│ 60 │->│ 90 │
└─────┘ └─────┘ └─────┘ └─────┘ └─────┘
In colour Fax:
┌─────┐ ┌─────┐ ┌─────┐ ┌─────┐
│ 240 │->│ 360 │->│ 120 │->│ 180 │
└─────┘ └─────┘ └─────┘ └─────┘
The indicator shows the number of lines per minute (LPM). Select the desired
IOC by clicking on the IOC indicator, which is to the right of the mode
indicator, or press <F6>.
In B&W Fax mode:
┌───┐ ┌───┐ ┌───┐
│288│->│576│->│864│
└───┘ └───┘ └───┘
In colour Fax mode:
┌───┐ ┌───┐
│288│->│204│
└───┘ └───┘
The Index Of Cooperation indicates the aspect ratio of the picture. When you
select 360 LPM automatically an IOC of 204 will be set.
To the right of the IOC indicator you will find the shift indicator.
┌───┐ ┌───┐
│800│->│300│
└───┘ └───┘
This is the difference between the frequency for black and the frequency for
white video. When transmitting a shift of 800 Hz is automatically set.
In B&W Fax mode you will find the next indicator to the right of the shift
indicator.
┌───┐ ┌───┐
│TOP│->│CLS│
└───┘ └───┘
In colour Fax mode it has one extra setting:
┌───┐ ┌───┐ ┌───┐
│RGB│->│TOP│->│CLS│
└───┘ └───┘ └───┘
RGB only available in colour mode: kicks r-g-b sequence one colour back
(causes the colour of the receiving picture to change), pressing the
<Ins> key has the same effect
TOP start reception at the top of the screen, pressing both the <Ctrl> and
<Home> keys has the same effect
CLS does the same and also clears the screen
Use the rx display sequence indicator to switch on and off reception.
┌──┐ ┌──┐
│1 │->│X │
└──┘ └──┘
1 = screen 1 (= reception on)
X = no screen (= reception off)
Various parameters in the Fax mode can be changed by clicking the PARAM menu
button.
╔════════╗ ╔════════╗
║ PARAM ║ -> ║ <LEFT ║
╚════════╝ ╚════════╝
╔════════╗
║ >RIGHT ║
╚════════╝
╔════════╗
║ VIDEO ║
╚════════╝
╔════════╗
║ CALIB ║
╚════════╝
╔════════╗
║ AUTO ║
╚════════╝
Move reception to the <LEFT or to the >RIGHT by clicking on the corresponding
buttons.
Click the VIDEO menu button to do some realtime image processing.
╔════════╗ ╔════════╗
║ VIDEO ║ -> ║ INVERT ║
╚════════╝ ╚════════╝
╔════════╗
║ MIRROR ║
╚════════╝
invert invert the incoming videosignal (black becomes white and white
becomes black)
mirror the incoming videosignal will be written to screen in the opposite
direction
You probably will only use these commands for shortwave reception of
commercial (weather)stations in B&W Fax modes.
The CALIB button is used when computing the xtal calibration factor.
╔════════╗
║ AUTO ║
╚════════╝
For automatic reception of Fax pictures click the AUTO menu button. This will
activate the Fax auto mode. MSCAN will now wait for a starttone. Once detected
it will determine the transmissions IOC and mode (B&W or colour). After that
it will wait for the synchronization signal and use it to determine the LPM
and shift and synchronize reception. It will then wait for the start of the
picture and begin reception. When the stopttone is detected the picture will
be saved to the auto directory and MSCAN will wait for a next transmission.
Pictures will be saved with the following name: mmddhhmm
(month/day/hour/minute). The auto mode can be aborted by pressing <Esc> or
right mouse button.
2.5.4 Transmitting pictures in Fax modes
After loading or digitizing a picture notice that the endmarker will be
automatically placed at the lower border of the picture. If you want to
transmit more or less of this picture, you can change the position of the
endmarker by clicking the endmarker indicator:
┌──┐
│--│
└──┘
Now position your mouse at the desired position and click again, the endmarker
will move to this new position. Optionally select the desired LPM and IOC and
click the RX/TX indicator, or press <F9> to start the transmission. To abort
the transmission click the RX/TX indicator, or use <F9> until it shows 'RX'.
2.6 Processing pictures with the toolkit
Press the TOOLKIT menu button to activate all image processing functions.
╔════════╗ ╔════════╗
║TOOLKIT ║ -> ║ MIRROR ║
╚════════╝ ╚════════╝
╔════════╗
║ COLOUR ║
╚════════╝
╔════════╗
║ ASPECT ║
╚════════╝
╔════════╗
║ MOVE ║
╚════════╝
╔════════╗
║ DRAW ║
╚════════╝
╔════════╗
║ DEBUG ║
╚════════╝
Click MIRROR to swap left and right sides of a screen.
Click COLOUR (only in colour modes) to change the colours of a picture on
screen (colours will be 'rotated').
Click ASPECT to correct a picture which is received in the wrong IOC.
Click MOVE to redefine the top-left corner of a picture. This will be useful
in Fax modes if a picture has been received with bad synchronization.
Click DRAW to draw pixels on the screen using your left mousebutton. Drawing
is done in the selected fontcolour.
The DEBUG menu button is meant for technical support only.
2.7 Managing the spectrum
The spectrum occupies the left part of the console and shows the frequency
spectrum of the received or transmitted signal. In SSTV modes it also features
a sync indicator which is the little square box above the 1200 Hz marker.
Whenever MSCAN is correctly synchronized to an SSTV station a white dot will
appear in this box.
By pressing the SPECTRUM menu button the following submenu will be presented.
╔════════╗ ╔════════╗
║SPECTRUM║ -> ║vSHRINK ║
╚════════╝ ╚════════╝
╔════════╗
║^EXPAND ║
╚════════╝
╔════════╗
║ <LOWER ║
╚════════╝
╔════════╗
║>HIGHER ║
╚════════╝
╔════════╗
║DEFAULT ║
╚════════╝
╔════════╗
║ LOAD ║
╚════════╝
╔════════╗
║ SAVE ║
╚════════╝
This menu is used when calibrating the interface's demodulator. It can also be
used to (temporarily) change the spectrum calibration, e.g. to compensate for
a station which has a frequency deviation in sync- and or videotones.
The reception spectrum can be shifted using the <LOWER and >HIGHER menu
buttons. Pressing the <LOWER button decreases all frequencies (darker video)
and pressing the >HIGHER button increases all frequencies (brighter video). You
can also vSHRINK (less contrast) or ^EXPAND (more contrast) the spectrum, this
will leave the 1200 Hz frequency unchanged.
Other available menu buttons are:
DEFAULT loads the default calibration
LOAD loads the last stored calibration
SAVE saves current calibration to disk.
In transmit mode the spectrum menu button shows the following submenu.
╔════════╗ ╔════════╗
║SPECTRUM║ -> ║ 1000Hz ║
╚════════╝ ╚════════╝
╔════════╗
║ 1200Hz ║
╚════════╝
╔════════╗
║ 1500Hz ║
╚════════╝
╔════════╗
║ 2300Hz ║
╚════════╝
╔════════╗
║ 2400Hz ║
╚════════╝
╔════════╗
║ APT ║
╚════════╝
Pressing a button causes MSCAN to transmit the corresponding tone for 5
seconds.
╔════════╗
║ CALIB ║
╚════════╝
If the Miniscan interface is used, a CALIB button will be available.
When a TX Interface is selected that has a programmable output level (Miniscan
and Ad Lib), the LEVEL menu button will be displayed.
╔════════╗
║ LEVEL ║
╚════════╝
After clicking on it, choose the desired output level and press OK.
Pressing APT shows:
╔════════╗ ╔════════╗
║ APT ║ -> ║ 200Hz ║
╚════════╝ ╚════════╝
╔════════╗
║ 300Hz ║
╚════════╝
╔════════╗
║ 450Hz ║
╚════════╝
╔════════╗
║ 675Hz ║
╚════════╝
Pressing a button causes MSCAN to transmit the corresponding starttone, which
are used in Fax modes.
2.8 Exiting the program
Clicking the OK indicator twice will cause MSCAN to terminate. Pressing <Alt-
X> or <Alt-Q> or <F10> has the same result.
APPENDIX I - INTERFACES
MSCAN supports many interfaces. The comparison chart in part A of this
appendix will give you a good idea which interface suits you best. Part B will
tell you something more about each interface and how to install, and if
necessary calibrate, it.
A Interface comparison chart
┌─────┬─────┬─────┬─────┬─────┬─────┬─────┐
│OPAMP│OPAMP│OPAMP│Easy-│View-│Mini-│Multi│
│spkr │TxD │AdLib│Fax │Port │scan │scan │
┌──────────────────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┤
│multitasking │ ■ │ │ ■ │ ■ │ ■ │ ■ │ ■ │
├──────────────────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┤
│RX noise filtering│ │ │ │ │ ■ │ │ ■ │
├──────────────────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┤
│effective DSP │ ■ │ ■ │ ■ │ │ ■ │ ■ │ ■ │
├──────────────────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┤
│RX picture quality│ │ │ │ ■ │ ■ │ │ ■ │
│independent of PC │ │ │ │ │ │ │ │
├──────────────────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┤
│TX picture quality│ │ │ ■ │ ■ │ ■ │ ■ │ ■ │
│independent of PC │ │ │ │ │ │ │ │
├──────────────────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┤
│high RX resolution│ │ │ │ │ ■ │ │ ■ │
├──────────────────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┤
│high TX resolution│ │ │ ■ │ │ ■ │ ■ │ ■ │
├──────────────────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┤
│>500000 RX colours│ ■ │ ■ │ ■ │ │ ■ │ ■ │ ■ │
├──────────────────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┤
│>500000 TX colours│ ■ │ ■ │ ■ │ │ │ ■ │ ■ │
├──────────────────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┤
│RX insensitive to │ ■ │ ■ │ ■ │ ■ │ │ ■ │ ■ │
│harmonics in audio│ │ │ │ │ │ │ │
├──────────────────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┤
│sine wave output │ │ │ ■ │ │ ■ │ ■ │ ■ │
├──────────────────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┤
│no calibration │ ■ │ ■ │ ■ │ ■ │ │ ■ │ │
├──────────────────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┤
│software output │ │ │ ■ │ │ │ ■ │ │
│level control │ │ │ │ │ │ │ │
├──────────────────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┤
│no external power │ ■ │ ■ │ ■ │ │ ■ │ ■ │ │
│supply required │ │ │ │ │ │ │ │
├──────────────────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┤
│Hamcomm compatible│ ■ │ ■ │ │ │ │ ■ │ │
└──────────────────┴─────┴─────┴─────┴─────┴─────┴─────┴─────┘
All information is based on both studying the design and testing the hardware.
Based on information available at 11-07-96. The PCIO-bus is not discussed here
since it is not a dedicated SSTV & Fax interface and is only available in
Holland.
B Installation of each interface
1. OPAMP
This is a very simple interface circuit which consists of a single OPAMP for
decoding signals. This interface is also known as Hamcomm or JV-FAX interface.
It connects to a serial port and does not require an external power supply.
2. Microscan RX
The Microscan RX interface is a OPAMP based interface developed by CombiTech.
It has a 'pass through' connector so that the serial port is still free for
other interfaces like a telephone modem or TNC. For connection to the receiver
a cable with mini jack connector is attached. It is connected to the serial
port and does not require an external power supply.
3. PC speaker
For generating the TX signal the PC speaker can be used. For most PCs an
external connection has to be made which is connected to the speaker inside
the PC. Use a low-pass filter to remove most of the unwanted harmonics from
the signal.
4. TxD pin
An easy method of getting your TX signal is using the TxD pin of the serial
port. A low-pass filter must be used to remove most harmonics. Because the PC
has to generate this audio signal, no multi-tasking is possible during
transmit.
5. Ad Lib
Any sound card that is Ad Lib compatible can be used as TX interface for MSCAN
(together with an OPAMP interface for RX). Because the Sound Blaster cards are
also Ad Lib compatible, all Sound Blaster compatible cards are also suitable.
For best results, set the volume on your sound card to maximum. Use a
potentiometer, best located near your transmitter, to adjust the level as
required. Fine tuning can be done in MSCAN (click SPECTRUM LEVEL during TX).
If your sound card has a mixer chip, set it for maximum volume on the FM
channel and master output, and set all other channels to zero.
6. Multiscan
The Multiscan modem consists of two boards (one for receiving and one for
transmitting) which can be connected to each other. The receive board can also
be used stand-alone. The Multiscan uses a high-quality PLL circuit for
decoding and a sinewave generator for generating signals. This ensures the
best pictures even under worse conditions.
First install the Multiscan interface by connecting it to a suitable radio and
to an unused serial port on the PC.
Radio connections
Pin 1 - transmit audio (connect to MIC
input of transmitter)
Pin 2 - ground connection
Pin 3 - receive audio (connect to audio
output of receiver)
Pin 5 - PTT (connect to PTT of
transmitter)
Computer connections
Pin 2 - Receive Data from
Multiscan
Pin 3 - Transmit Data to Multiscan
Pin 5 - ground
If you have not bought an assembled Multiscan interface, or if you replaced
some part of it, you will need to calibrate the Multiscan interface. Both the
demodulator and modulator of the Multiscan interface need to be calibrated.
For calibration of the demodulator a software-approach is used. The modulator
is calibrated using the potentiometers on the TX board.
Calibrating the demodulator (RX)
When calibrating the demodulator you are in fact adjusting the software to
match the characteristics of the hardware (software calibration). Calibration
should be done using a tone generator which has an adjustable frequency. It is
however also possible with the help of another amateur station.
Use the following steps for calibration:
1) Switch the program to SSTV mode and click the SPECTRUM menu button.
2) Apply a 1200 Hz tone to the audio input of the interface. A bar will
appear in the spectrum. In the top-right corner the frequency is
displayed, this will have to be 1200. You do this by clicking on the
<LOWER and >HIGHER menu buttons. With these you can shift the entire
spectrum downwards or upwards. The bar will now be positioned exactly
under the sync indicator.
3) Apply a 2300 Hz tone. To get the frequency '2300' displayed in the
spectrum use the ^EXPAND and vSHRINK buttons to expand or shrink the
entire spectrum. The bar will now be positioned above the right marker
(dot on the right).
4) When ready repeat the entire procedure again. Now you can write the
calibration factors to the configuration file using the save button.
If you do not have access to a tone generator you can also ask another amateur
to transmit the tones for you, if he also uses MSCAN this will be no problem
since the program has a special feature for this purpose. In this case simply
connect the interface to the audio output of your receiver.
It is also possible to calibrate the demodulator using a high-quality SSTV
signal. This will however give a less exact result. The procedure for
calibrating using an SSTV signal is not much different:
1) Apply the SSTV signal to the interface. Use the <LOWER and >HIGHER buttons
to get a good synchronization (1200 Hz adjustment). You will now see a
bar under the sync indicator.
2) Use the ^EXPAND and vSHRINK buttons to get the right grey shades in the
picture. These values have to be spread all over the 1500-2300 Hz part of
the spectrum (between the two markers).
3) You can now store the acquired calibration factors in the configuration
file using the SAVE button.
Calibrating the modulator (TX)
Calibration of the modulator should only be required if you have just
completed building the Multiscan or if you have changed any parts. If you have
bought a built unit the modulator should already be calibrated.
The modulator is calibrated as follows:
1) Switch the program into the transmit mode by clicking on the RX
indicator. The indicator will now show TX.
2) Enable the spectrum by clicking the SPECTRUM menu button. The buttons
1200, 1500 and 2300 allow you to generate the tones 1200, 1500 and 2300
Hz.
3) Select the tone 1200 Hz. Measure the frequency of the signal that the
modulator generates. You can do this at the output of the board. The
output level can be adjusted with R4 on the Multiscan transmit board. If
your counter is not sensitive enough you can also measure the signal at
R3. Adjust the frequency with R7 to exactly 1200 Hz.
4) Now select a tone of 2300 Hz. Adjust the measured frequency with R6 to
exactly 2300 Hz.
5) Repeat the previous procedure. The modulator is now precisely calibrated.
When you now select a tone of 1500 Hz you should measure this frequency
at the output. A deviation of a few Hz is allowed.
6) Press your right mousebutton to leave the spectrum mode, and click the TX
indicator twice to switch back to the receive mode.
If you do not possess a frequency counter you can also simply transmit the
signal and ask another amateur to measure it for you. If this amateur also
uses MSCAN then this is easy: he only has to press the SPECTRUM button and
read the displayed frequency.
7. EasyFax
Connect your EasyFax interface as instructed in the EasyFax manual. Make sure
the interface is switched on before starting MSCAN. At startup MSCAN will then
automatically initialize the EasyFax interface.
8. ViewPort VGA
To optimize your ViewPort VGA interface for MSCAN you will have to calibrate
both the interface and the software. Calibration is done almost in the same
way as described for Multiscan, except other tones are used. The following
procedure is recommended (you can use MSCAN to generate the 1000 Hz and 2400
Hz tones).
1) Hardware calibration - see also the ViewPort VGA documentation
a) set Rv (video gain) and Ro (offset) to about mid range
b) input 1000 Hz (not 1200!) and adjust Ro for 0.00 Vdc at TP3
c) input 2400 Hz (not 2300!) and adjust Rv for 5.00 Vdc at TP3
d) repeat steps b and c as required
2) Software calibration
a) connect the ViewPort interface to your PC
b) configure MSCAN by entering 'MSCAN /C' and answering all questions,
when asked for RX interface choose ViewPort, when asked for spectrum
calibration factor low and high press <Enter>
c) when ready click on SPECTRUM menu button
d) click DEFAULT
e) input 1200 Hz and use the <LOWER and >HIGHER buttons to get a reading
of 1200 Hz
f) input 2300 Hz and use the vSHRINK and ^EXPAND buttons to get a
reading of 2300 Hz
g) repeat steps e and f as required
h) click on SAVE to write the spectrum calibration factors to disk
P.S.: This new calibration will make your ViewPort interface incompatible with
other programs, however in combination with MSCAN it will perform best!
Thanks to the manufacturer of ViewPort VGA, A&A Engineering in Anaheim
California, for their hardware support, and to John Montalbano KA2PYJ for his
software support.
9. Miniscan
A very handy compact interface that can be plugged directly into the serial
port. Miniscan uses a sinewave generator to create a distortion free audio
signal. A built-in Hamcomm emulator ensures compatibility with many other
programs. Besides making a connection cable for the transceiver, no other
connections need to be made, not even a power supply is needed. Calibration is
done as follows:
1) Connect the output of the Miniscan interface to its input.
2) Select M1 SSTV mode.
3) Switch the program into the transmit mode by clicking on the RX
indicator. The indicator will now show TX.
4) Enable the spectrum by clicking the SPECTRUM menu button. Click the CALIB
button. The Miniscan will now fully automatic calibrate its modulator!
5) Click your right mouse button twice to leave the spectrum menu and click
the TX indicator twice to switch back to receiving mode.
If you connect Miniscan to another RS-232 port you must recalibrate it for
best performance.
The output level can be comfortably adjusted as follows:
1) Connect Miniscan to your transmitter. Find a free frequency and set your
transmitter to low power.
2) Activate TX and click SPECTRUM. Select 1500 Hz.
3) Click LEVEL and select the desired output level. Click OK to confirm.
Ready!
APPENDIX II - SUPPORTED VIDEO DIGITIZERS
Ofcourse you can use any video digitizer to make pictures and import them as a
file in MSCAN. However if you use one of the supported digitizers, loading a
picture from e.g. your camera into MSCAN is as easy as clicking a button! You
can digitize any video signal even while receiving or transmitting!
A Iris
The best digitizer with extreme high resolution, so very suitable for Fax
modes. The Iris needs no special preparation. Simply plug it into your PC and
you are ready!
B Video Blaster
MSCAN supports all Video Blaster models: the original model, SE, FS200 and
SE100.
Install your Video Blaster as is mentioned in the Video Blaster manual. If
possible choose for frame buffer address 'DISABLED', this will enable you to
digitize video without disturbing the timing in reception and transmission.
Run the adjustment program (.....SET.EXE) and adjust the video for each input.
Now disconnect your monitor from the Video Blaster and connect it directly to
the video card (the Video Blaster does not support the video overlay in true
colour). In some cases it can be necessary to also remove the flatcable
between the Video Blaster and the video card. Make sure the Video Blaster
driver (.....DRV.EXE) is loaded before running MSCAN (place it in your
AUTOEXEC.BAT).
C ComputerEyes/RT
This video digitizer is very popular in North America. Refer to the
ComputerEyes/RT manual for correct installation.
APPENDIX III - TROUBLESHOOTING
Because MSCAN is a complex multitasking program, it will take up all capacity
of the PC. Therefore no extra tasks can be performed by the PC. Some problems
which may occur because of this are discussed here.
Use of resident programs
Resident programs (permanently present in memory) may cause extra system
interrupts. Some caching programs for harddisk and/or floppydrives temporary
disable the system interrupts. This is not allowed because this will desturb
timing in MSCAN. Some memory managers (such as EMM386, QEMM or 386MAX) do an
even better job in disturbing timing and may crash the system. If you
experience problems, try booting from a 'clean' DOS diskette and then start
MSCAN. If there are still problems, try removing hardware (such as scanner
cards) from your PC which could be generating interrupts or DMA requests.
No image on the monitor
Check if you have selected the correct chipset. If you choose VESA, check if
your video card requires a VESA driver to be loaded. If the video card is not
fully VESA compatible you can try using a universal VESA driver like UNIVBE.
Is your adapter capable of displaying 16.8 million colours (truecolour) with a
resolution of 640*480? Are you sure no memory manager or incompatible mouse is
causing the problem?
Interference in reception
If loading a picture interferes with the reception of a picture (dots or
stripes in picture), chances are a diskcache program or memory manager is the
cause. If not, probably your computersystem is too slow. Remove all caches,
memory managers etc. Use of the Multiscan modem instead of e.g. Hamcomm
relieves the computer from its decoding task and so solves this problem and at
the same time gives you clearer and sharper pictures. If you do not want to
change your interface a faster CPU or video card may also solve the problem.
Image shifts when loading picture
If loading a picture from disk causes the receiving (or transmitted) image to
shift to the left, and no cache program is installed, your harddisk/BIOS
combination is the cause of the problem. The only solution to this problem is
installing another mother board or using another PC.
Dots in screen at random places
If this occurs when doing multiple tasks at once, or when in fast modes like
M2 or S2, then your PC is too slow. If not caused by resident programs, then
you will have to upgrade to a faster processor or faster video card.
Problems after unattended operation
If problems occur when during a certain time no key has been pressed, and the
mouse has not been used, then your computer is probably of the 'green' type.
This means it has a built-in energy saver that switches of various parts of
the PC when e.g. no key is pressed. Reboot your PC, activate the setup and
disable this energy saver. If you have sufficient knowledge and if you want to
keep using this facility, then you can try to make it sensitive to interrupts
used by MSCAN.
Mouse does not work
Try using a different mouse driver, e.g. one from Logitech or Microsoft.
APPENDIX IV - MODE DESCRIPTIONS
MSCAN supports a number of modes. The outline specification for these modes is
defined below.
A SSTV
SSTV pictures are transmitted only by radio amateurs. They can be received on
HF (e.g. 3730 kHz LSB and 14.230 MHz USB) and on VHF (e.g. 144.500 MHz FM) and
UHF frequencies.
B&W SSTV
SSTV is used by radio-amateurs to transmit images via a narrow (3kc) bandwidth
radiochannel. The image is transmitted in lines, each line is preceded by a
line syncpulse of 1200 Hz. Each image is preceded by a longer frame syncpulse
of 1200 Hz. The video is modulated on a 1900 Hz carrier with an 800 Hz shift
(1500 Hz is black, 2300 Hz is white).
Wraase colour SSTV
Derived from B&W SSTV. To be able to transmit a colour image, each line is
sent three times: one for the red colours, one for the green colours, and one
for the blue colours. The receiver combines the three lines to one colour
line. When transmitter and receiver are not synchronized, false colours will
appear at the receiver.
New colour SSTV modes (martin and scotty)
Instead of sending three lines, every line is divided into three parts, one
for every colour. After receiving a line syncpulse, the receiver cannot be
mistaking about the correct colour sequence.
Robot 72 s mode
Robot mode, named after Robot Research Inc., is a composite mode. An image is
broken into two components. Each scan line of an image is sent as a luminance
part, containing the brightness of the image, and a chrominance part
containing the colour information. The chrominance part is sent in a lower
resolution, thus resulting in an overall shorter transmission time. A major
disadvantage of this mode is 'tinting'. If a received image is tuned off
frequency, the image will 'tint' itself red or green, depending on the tuning
offset.
B Fax
Modulation
Fax pictures on short-wave and long wave are normally transmitted in FM. That
means that the transmitter is keyed between two frequencies of which the one
corresponds to white, the other to black. When transmitting half tone
pictures, the transmitter frequency is continuously shifted between the
frequency for black and the frequency for white.
Half the difference between the frequency for white and the frequency for
black is called signal deviation. This deviation is, by standard, 400 Hz for
short-wave and 150 Hz for long wave transmissions. Furthermore, the higher
transmitter frequency should correspond to white. The shift is twice the
deviation. The Fax signals should be received with an SSB receiver so that it
outputs an FM-modulated audio sub carrier.
This sub carrier is then fed to the interface that converts the different
audio frequencies into digital intensity information that can be processed by
the computer.
Two terms you will have to know are IOC and LPM. IOC stands for Index Of
Cooperation, which is a measure for the vertical resolution of a picture; an
incorrect IOC will result in a picture which is too short or too long. The
speed in which a picture is transmitted is indicated in LPM, which stands for
Lines Per Minute.
Automatic Picture Transmission
Automatic Picture Transmission (APT) is used by commercial Fax stations to
enable a fully automated unattended reception of the transmitted pictures. At
the start of the transmission a start tone is transmitted for some seconds,
which is recognised by the receiving unit. At the end of the transmission a
stop tone is sent that switches the receiving unit back to standby mode. The
tone which is sent can be used to identify the IOC of the transmitting
station. Most amateurs now also use APT in their transmissions.
Colour Fax
By looking at colour SSTV modes, radio amateurs have developed a method of
transmitting colour Fax images. Every line is sent for this purpose three
times: one time for the red colours, one time for the green, and one time for
the blue colours.
Start and stop tones
In accordance with international standards, MSCAN uses the following start-
and stoptones in B&W Fax modes:
IOC start stop
288 675 Hz 450 Hz
576 300 Hz 450 Hz
The colour Fax mode has been developed by radio amateurs, and unfortunately no
international standard has been set. However the following start- and
stoptones are semi-standard:
IOC start stop
204 200 Hz 450 Hz
288 200 Hz 450 Hz
As you can see both IOCs have the same starttone of 200 Hz. Because the auto
mode of MSCAN uses the starttone to determine the IOC, it will always select
an IOC of 288, except for the 360 LPM mode which is mostly used with an IOC of
204.
Commercial Fax stations can be received all over the long- and shortwave
bands, in Europe e.g. on 134 kHz (USB), 4778 kHz (USB) and 8145 kHz (USB).
Radio amateur Fax transmissions can be received on 14.230 MHz (USB) and
144.700 MHz (FM).
APPENDIX V - AGENTS AND CONTACTS
If you want to receive information about or order any of our products, contact
the agent or contact person for your region, or contact us directly. Note that
a contact person is a radio amateur who is eager to help, but is doing this in
his spare time and without commercial profit.
Agents and contacts:
Australia Art van Esch VK4GO, Imperial-Surf, 23C/80, The Esplanada
(contacts) Surfers-Paradise 4217, Australia.
Tel/Fax: (07) 5538 1652,
Email: surf@winshop.com.au
Chris Watts VK3DNH, RMB 3440, Hansen Road, Rochester,
Victoria 3561, Australia.
Tel: (054) 865400, Email: crac@echuca.net.au
Denmark Norad Tele-center a/s, Svend Sorensen OS4SX,
Frederikshavnsvej 74, DK-9800 Hjorring, Denmark.
Tel: 98909999, Fax: 98909988
France TBL Club, Francis Roch F6AIU, F-70120, La Roche Morey,
(contact) France.
Hungary KáTÉ BT., Tibor Osztie HA9SB, 3529 Miskolc,
Perczel M. u. 45/A, Hungary.
Tel: (046) 365643, Fax: (046) 360009
Japan Kiyotada Shimizu JA6AP, 1-21-5, Hayama, Munakata city,
(contact) Fukuoka-ken, 811-41 Japan.
Tel/Fax: (092) 8436801
United Kingdom AMDAT, Terry Rowe G8NNU, 4 Northville Road, Northville,
Bristol, BS7 ORG, England.
Tel: (0117) 9699352, Fax: (0117) 9872228