World of Ham Radio 1997

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▒▒▒▒▒ ▒ ▒ ▒▒▒▒▒ ▒▒▒ ▒ ▒ ▒▒▒ ▒▒▒ ▒ ▒ ▒ ▒ ▒ ▒ ▒ ▒ ▒ ▒ ▒ ▒ ▒ ▒ ▒▒▒▒ ▒▒▒▒▒ ▒ ▒▒▒▒ ▒ ▒ ▒ ▒ ▒ ▒ ▒ ▒ ▒ ▒ ▒ ▒ ▒ ▒ ▒ ▒▒▒ ▒ ▒ ▒ ▒ ▒ ▒ ▒▒▒ ▒ ▒▒▒ a FAX/SSTV program for IBM PCs and compatibles by ▒▒▒▒ ▒ ▒ ▒▒▒ ▒▒▒▒▒ ▒ ▒ ▒ ▒ ▒ ▒ ▒ ▒ ▒ ▒ ▒ ▒ ▒ ▒▒ ▒▒▒ ▒ ▒ ▒ ▒ ▒ ▒ ▒ ▒ ▒ ▒ ▒ ▒ ▒ ▒▒▒▒ ▒ ▒ ▒▒▒ ▒▒▒ ▒ ^ ======== /│\ // \│/ │ // \\ │ ┌───────┴───────┐ ========>> ┌───────┴───────┐ │ ___ │ // │ ___ │ │ /. .\ │ │ /. .\ │ │ │ √ │ │ │ │ √ │ │ │ │ └─┘ │ │ │ │ └─┘ │ │ │ \_ _/ │ │ \_ _/ │ │ F │ │ F │ │ \A/ │ │ \A/ │ │ X │ │ X │ │Tx! / \ │ │Rx! / \ │ │ S S T V │ │ S S T V │ └───────────────┘ └───────────────┘ Rev: 931001 Eberhard Backeshoff, Obschwarzbach 40a, D-40822 Mettmann Germany T A B L E O F C O N T E N T S =============================== Introduction 3 ============ Interface hardware requirements 5 Program configuration 6 Running the program 13 =================== Program start 13 Fax reception 15 The mode editor 21 Date driven FAX reception and date editor 24 Show and send pictures 29 Movie options 32 SSTV 33 JV-Color, a color fax transmit/receive mode 36 Something about FAX transmissions: 39 ================================== How the ATC works 41 Phasing to low orbiting satellites 41 Picture masks for the reception of geostationary satellites 42 "Simplest" demodulator circuit 43 Some SVGA modes 44 Frequencies, reception etc. 46 Disclaimer 48 Copyright notes etc. 48 JVFAX 6.0, a FAX-/ SSTV-program for IBM PCs and compatibles page 3 Introduction ============ JVFAX 6.0 is a multi purpose program for the reception of both weather chart and photo style fax. For radio amateurs, there is an additional transmit-option for FAX and a SSTV transmit/receive facility. Fax reception can be performed fully automated, supporting time schedules. The automatic creation of weather movies is supported when receiving geostationary satellites. Depending on the interface an intensity resolution up to 256 grey shades can be gained. Spatial resolution depends on the index of co-operation being selected and can be up to 2400 dots per line. In conjunction with an adequate interface a so called Automatic Tuning Control (ATC) can be enabled when receiving FM-FAX, which greatly facilitates the tuning process. This ATC also compensates a receive frequency drift within wide ranges. The program can be configured for a wide range of ports and interfaces. See file "INTERF.DOC" for a more detailed description and for the availability of demodulators or kits. JVFAX runs on any IBM PC or 100% true compatible and under DOS versions higher or equal to 3.0. You need at least a VGA graphics card to run JVFAX 6.0. JVFAX 6.0 supports SVGA cards in 16 or 256 color mode with different resolutions. Drivers for some 8/9 or 24 pin printers are includes, and a driver for the HP-Laserjet. On slow machines, however, the program will show a degraded performance. (8088/86 or slow 286'2) Optimum performance is gained when using at least a '386 machine with a SVGA-256 color card and at least 4 MB of RAM. JVFAX will not run in a multitasking environment such s MS-WINDOWS or OS/2! Pictures can be viewed, stored or printed during reception. Stored pictured can be viewed, zoomed, printed or retransmitted. Zoom magnification and width/height ratio can be freely chosen. Zoomed portions of a picture can be stored as independent pictures. For the storage of the pictures the commonly used GIF file format is used. By this, you have access to many shareware or even freeware tools for picture post processing. Also, there are a lot of conversion programs in the public domain to transfer this format to others, e.g. TIFF, PCX, ... An export routine to TIFF is directly implemented. If the program is run in SVGA 256 colour mode then weather pictures can be viewed in false colours. The following IOCs and drum speeds (LPMs) are available for FAX reception: IOC: between 200 and 576 LPMs : 48, 60, 90, 120, 180*, 240* LPMs marked with a * can be run on slow computers with reduced resolution only. APT operation is fully supported, including automatic recognition of IOC in weather chart transmissions. JVFAX 6.0, a FAX-/ SSTV-program for IBM PCs and compatibles page 4 The APT mode can be replaced by choice with an so called "Squelch mode" e.g. for the reception of low-orbiting satellites. Synchronizing to the APT bursts of the NOAA and METEOR satellites is also possible. By this, one can filter out the VIS or IR portion af a NOAA picture transmission. Automatic phasing to normal FAX transmissions is possible with normal as well as inverted phasing signals. For the coverage of the different types of FAX transmissions (weather charts, weather pictures, press ...) up to 20 modes can be defined within the program. These modes will store defaults for IOC, LPM, APT tones, number of grey shades etc. When displaying pictures on the screen always the full screen format will be used in order to achieve the maximum possible resolution. Internally, however, the program will generally use a much higher resolution that is by default: resolution (in dots per line) := IOC * Pi. By this, you can take zooms out of a stored picture that will show details not normally recognisable on the screen. Alternatively you can set the resolution for each mode individually. The program's time consumption to perform the necessary calculations for FAX reception grows proportionally with "resolution*LPM". The dot clock, that is the speed that subsequent dots in a line have to be stored with, calculates to (dots per line) * Pi * LPM / 60 [Hz]. On slow PCs (4,77 or 7 MHz XT's or AT's) it might be necessary to put a limit to the maximum dot clock (also known as "interrupt frequency") to get the program run properly. For this purpose a maximum interrupt frequency can be set in the configuration routine. By such a limit pictures received with higher drum speeds and high IOCs will be processed with reduced resolution. On VGA cards in 16 colour mode 16 true intensity levels are shown and an interpolation of intermediate intensity levels is done by dithering. On SVGA cards in 256 colour mode up to 64 real intensity levels will be shown, or up to 256 different colours. For each mode you can define with how many intensity levels a picture shall be stored or displayed. Maximum is 256 levels, minimum 2. Reducing the number of intensity levels to an amount adequate for the contents of the pictures will reduce disk storage requirements considerably. JVFAX 6.0, a FAX-/ SSTV-program for IBM PCs and compatibles page 5 Interface hardware requirements =============================== To operate this program you need some kind of interface. The purpose of such an interface is to convert the analogue audio signal that is provided by your receiver in a digital form that is readable from your computer. JVFAX uses different interfacing techniques, which are described in "INTERF.DOC". The standard method is to interface the demodulator via a serial port. When running the program on a serial port however, not the serial input line of this port is normally used but instead the four handshake lines DCD, RI, DSR and CTS are utilised as a kind of 4 bit parallel port. That helps to reduce hardware expense on the interface side. If the interface should deliver more than 16 grey levels on such a "serial port", a multiplexing technique is used: Schematics for a sample 256 grey-level AM/FM demodulator can be found on the disk. (AM_FM1.GIF .. AM_FM6.GIF) In the meantime a lot of interfaces or interface kits are available. An overview of the kits and interfaces available in Germany is also given in "INTERF.DOC" This overview may be incomplete. As an alternative you can have the computer do all the work and make it decode the audio signal. For that you must amplify the audio to a RS232 compatible level using a simple comparator circuit. This will only work if the comparator is connected to a serial port that is configured to use IRQ4 or IRQ3 and if the PC is fast enough. When using this method, some memory-management programs such as EMM386 might interfere with this "simplest" solution and might have to be disabled for the program to run with acceptable results. But even then the results obtained will be worse than these obtained with a "more sophisticated" type of interface. A circuit diagram for a simple comparator amplifier is shown later in this document. For transmitting purposes you can choose between a parallel or serial output or an audio signal output using the PC's built in speaker or the TxD pin of a serial port. The speaker signal as well as the serial TxD audio output can directly drive the transmitter after having passed some low-pass filter and voltage divider stages. In all transmitting modes the maximum intensity resolution is limited to 64 levels. When using the TxD audio output however, intensity levels are limited to about 13. JVFAX 6.0, a FAX-/ SSTV-program for IBM PCs and compatibles page 6 Program configuration ===================== You must have DOS 3.0 or higher to run this program. Since the program is quite memory consuming, using MSDOS 5.0 or higher is recommended. If you run the program for the first time a configuration routine will be called in which you have do define your graphic card, interface type etc. These settings are stored in a file JVFAX.CNF and won't have to be redefined on every program start. A program reconfiguration can be done anytime from the programs main menu. How to do the configuration: Run the program by entering JVFAX <-┘. Depending on if you have run the program before or not you will find yourself in the main menu or the configuration menu. If in main menu, enter "C" to switch to the configuration menu. Now the configuration screen appears that looks somewhat like this: (JV)-FAX 6.0 configuration screen ╒══════════════════════════════════════════════════════════════════════════════╕ │ │ │ Demodulator: 7 bits serial port addr: 03F8 IRQ: - LSB-SSTV-sync: yes │ │ │ │ Modulator: 6 bits on speaker addr: 0000 Bdrate: 57600 Dtarate: 4800 │ │ ____________________________________________________________________________ │ │ │ │ Graphics: ET4000 800x600x256 │ HIRES-movie: yes │ │ SSTV-graph.: ET4000 1024x768x256 │ Enable scrolling: yes │ │ Printer: IBM/Epson 8/9-pins │ Formfeed at end of pict.: no │ │ ____________________________________________________________________________ │ │ │ │ Allow tone alert at end of picture: no │ Max. interrupt frequency: 7500 │ │ Enable autolock when ATC is on: yes │ Clock-timer frequency: 1193181 │ │ ____________________________________________________________________________ │ │ Default picture directory: │ │ C:\FAX │ │ │ │ Store pictures in GIF89a: yes │ Miscellaneous settings: │ │ Callsign: DK8JV │ UTC time diff: 2 │ │ │ │ Enter baud rate for TX serial port (9600-57600) │ ╘══════════════════════════════════════════════════════════════════════════════╛ Hit <Ctrl>+<Enter> to terminate configuration session JVFAX 6.0, a FAX-/ SSTV-program for IBM PCs and compatibles page 7 You can step through the fields using cursor or TAB keys. Change field values using +, - or space key, or on some fields by simply entering a new value. You can terminate the configuration by pressing <Ctrl>+<Enter> at the same time. In the third last screen line a short context sensitive help text is shown. Follow the meanings of the fields: Demodulator: You can define how many different intensity levels your interface is capable to deliver and to which port it is connected. You can choose between serial, parallel and comparator (on serial) port. Additional interfacing types are implemented which are described in "INTEF.DOC". Address: Enter the address of the port that your interface is connected to. When using a serial port you will have to enter the base address of your serial card, e.g. 03F8h for COM1:. IRQ: For some interfacing types (e.g. "HAMMCOMM") it is necessary to enter the correct IRQ level here. Normally these are 4 for COM1, 3 for COM2 and 7 for LPT1. LSB-SSTV-Sync: Only applicable for SSTV-reception. You can receive SSTV either if your interface delivers the SSTV sync signal in the two least significant bits (active low) or if your interface can be switched to cover 800 Hz deviation. In the first case, you must set this entry to yes, else, and when using the "simplest" interface, set it to no. Modulator: Choose between speaker, parallel or serial port or serial audio. The following address field has the same meaning as the one above and is meaningless when having selected speaker output. Baud rate: Only relevant if you have chosen serial port in the modulator field. Data format is always 8 data bits, 1 stop bit and 1 start bit. The 6 bits of intensity information are right aligned within the byte. The baud rate field will also be used when a receiving interface that is capable of being controlled via the computer is connected to a serial port. Furthermore, this baudrate will be used when interfacing to a demodulator that transfers its data serially to your computer's serial port. JVFAX 6.0, a FAX-/ SSTV-program for IBM PCs and compatibles page 8 Graphics: Select a graphic mode applicable to your graphic card / monitor. You should first try if your graphics card will run with some of the "VESA" modes. Nearly all modern cards will do, but sometimes you will have to load a special TSR. (See manual of your graphics card) If you choose an "other SVGA" mode you will have to define some additional parameters within a sub menu that you can activate by pressing the <Escape> key. This menu looks like that: ╒═ customise SVGA parameters ══╕ │ │ │ Chipset: │ │ Tseng ET 4000 │ │ │ │ AH:00h AL:30h BH:00h BL:00h │ │ │ │ Dots per line: 800 │ │ Number of lines: 600 │ │ Screen aspect ratio: 10000 │ ╘══════════════════════════════╛ The field Chipset is needed only when you have chosen a 256 colour mode. If you don't find the chipset of your card in the choices available you will have to choose a 16 colour mode, instead. If you can provide me with bank switching information of a chipset not contained in the choices, please let me know. I will then try to implement a driver for that special chipset. Register values normally can be found in your graphic card manual. In 99 % of all cases only the AL register has to be set to the correct value and the other registers have to be set to 0. The fields dots per line and number of lines are self explaining. Screen aspect ratio means the ratio between horizontal and vertical dot density on your screen. This ratio is multiplied with 10000 and entered in the according field. Since a monitor screen has a height/width ratio of 3:4, one obtains for a 800x600 display: 600 / (800 * 3/4) = 1. in this case you would have to enter 10000. Using a 800*560 display would result in: 560 / (800 * 3/4) = 0,9333, so you would have to enter 9333. Use Screen T)est from the main menu to check if you'd choose a correct driver for your graphics card. JVFAX 6.0, a FAX-/ SSTV-program for IBM PCs and compatibles page 9 When using 16 colour SVGA modes the maximum resolution is limited to 800x600 pixels. This limitation is not valid for 256 colour SVGA modes. Terminate the SVGA parameter sub menu by hitting <Ctrl>+<Enter>. HIRES-movie: If you set this entry to yes, a weather movie will be generated with a resolution of 640x480x256 instead of 640x350x16. At the moment, this features will only work on graphics cards equipped with an ET4000 chipset. Enable scrolling: If set to yes you will have a scrolling type screen. If set to no, a picture on the screen will simply be overwritten by a new one. SSTV-Graph: To select a different video mode for SSTV reception For this field, everything discussed under "Graphics" is applicable. Printer: Select a driver appropriate for your printer. If in doubt, choose IBM 8/9 pin. If your printer should not be compatible with any of the predefined ones you can invoke a printer customising menu to do some "fine tuning". I will not describe this procedure because it highly depends on your printer. Please contact me, if you should have problems to make your printer run with this program. Formfeed at end of pict.: Set to no if you don't want each picture to be printed on a new page. If you're using a laser printer, a Formfeed will always be output to the printer at the end of a picture. A fine tuning of the patterns sent to the printer to represent the different intensity levels within a picture can be done from within the main menu by invoking P)rinter test. Allow tone alert at end of picture: If set to yes a short melody will inform you that a picture reception has been completed whenever a APT stop tone is detected. Max. interrupt frequency: This defines, in conjunction with the drum speed (LPM) and the index of co-operation (IOC) an upper limit for the obtainable resolution (dots per line). A weather chart transmitted with IOC 576 has a resolution of up to 1810 dots per line. Assuming a drum speed of 120 lines per minute this results in an interrupt frequency of 3620 Hz. JVFAX 6.0, a FAX-/ SSTV-program for IBM PCs and compatibles page 10 If you should recognise lost lines or similar strange effects when receiving fax pictures then your computer might be too slow to handle such high interrupt rates. You should then try to reduce the value indicated in this field to give your computer more time to "breathe". If you're running a machine with more than 12 MHz clock speed this normally won't be necessary. Enable auto lock when ATC is on: If set to yes the ATC will be "frozen" at the end of as phasing sequence until the end of the picture transmission. This is advantageous when receiving heavily jammed signals, since by excessive noise, the ATC might be interfered and produce unintended changes in picture intensity. Clock timer frequency: To guarantee for a proper FAX transmission both the transmitter and receiver have to use a highly constant scan speed. Not only this speed has to be highly constant but additionally it has to be exactly the same on the transmitting and receiving side to avoid slanting effects in the received picture. As a time base for this program serves the PC internal timer oscillator, that controls the PC's date/time clock. By reprogramming the timer controller, all necessary timings can be derived. Since this clock speed slightly varies from PC to PC you will recognise when first receiving FAX that the pictures will show some amount of skew. You can correct this with the "oblique skew" correction that will be explained later. If you know the exact frequency of your computers timer clock you can enter it here directly (a precision of some 10 Hz is absolutely necessary). If in doubt leave this field as is and perform the oblique skew correction later. Default picture directory: Enter a default directory for your received pictures to be stored within. If the directory doesn't exist, it will be created. Store pictures in GIF89a: At the moment, there are two kinds of GIF formats: 87a and 89a. While GIF89a enables the imbedding of application dependant information within the picture file, GIF87a does not. Unfortunately, some programs are not capable of handling the GIF89a format. FAX uses the application dependent information fields provided by GIF89a to store information about picture orientation etc. If you intend to use programs for the post processing of pictures received with JVFAX that cannot handle GIF89a frequently, you should set this field to no. In any other case this field should be set to yes. JVFAX 6.0, a FAX-/ SSTV-program for IBM PCs and compatibles page 11 Callsign: If you're a radio amateur and if you want to transmit pictures with this program, you must enter your callsign here. If this field is blanked, picture transmission will be inhibited. Miscellaneous settings: With the cursor positioned on this field, hit the <Escape> key to open a sub menu where you can set some default timing values etc. The miscellaneous sub menu looks that way: ╒═════════════════════════════MISC. SETTINGS═════════════════════════════╕ │ │ Control codes for R/C demodulators │ │ Start delay APT squelch: 5 │ │ │ Stop delay APT squelch: 30 │ Nrm: ATC: │ │ Squelch threshold: 300 │ FM 150 Hz: 41h 43h │ │ NOAA-sync threshold: 6.5 │ FM 200 Hz: 42h 45h │ │ METEOR-sync threshold 12 │ FM 300 Hz: 43h 47h │ │ TX start tone length: 4 │ FM 350 Hz: 44h 47h │ │ TX stop tone length: 4 │ FM 500 Hz: 46h 48h │ │ TX phasing sig. length: 6 │ AM 1: 49h 49h │ │ Quicksave: yes │ AM 2: 4Ah 4Ah │ │ Initial RX mode: 5 Ham 288b │ SSTV: 4Bh │ │ Ini-TX mode B/W: 5 Ham 288b │ │ │ Ini-TX mode Col: 4 HamColor │ off: on : │ │ Ini-SSTV mode: 17 Martin 1 │ TX-HW-filt: 52h 53h │ │ Max. # of pict./movie: 30 │ RX-HW-filt: 50h 51h │ │ Pause at movie end (s): 2 │ │ │ TX text heading: no │ Disable XMS use: no │ ╘════════════════════════════════════════════════════════════════════════╛ Start delay APT squelch: Time in seconds. If you have selected "squelch mode" when in FAX reception then a picture transmission is assumed to have started when for longer than the period entered here the program detects changes in signal amplitude. Stop delay APT squelch: Just like in the field above, the program assumes a transmission to have stopped when for longer than the time entered here there have been no further changes in the received signal. Squelch threshold: Threshold level for noise detection when running the APT "squelch" mode. Doesn't need to be changed normally. If APT switches to "Sq.on" if only noise is present, the you should decrease this value, else if APT will not switch to "Sq.on" even if there's a signal, then you can try to increase this value. NOAA and METEOR sync threshold: These are threshold levels for the low orbiting satellite tone burst recognition. Need not be altered normally. Decreade values, if the program doesn't synchronise at all or increase if synchronisation is faulty. TX start tone length: Length of APT start tone for picture transmission, in seconds. JVFAX 6.0, a FAX-/ SSTV-program for IBM PCs and compatibles page 12 TX stop tone length: Length of APT stop tone for picture transmission, in seconds. TX phasing sig. length: Length of phasing signal for picture transmission, in seconds. Quick save: If set to yes, every received picture will be stored to a temporary file in case both "Store to disk" and "Printer" are in off condition. At the end of the picture transmission you have the choice to save the previously stored picture permanently by hitting the "U" (U for q"u"ick) key. This very useful option can be disabled, e.g. if you have a PC with strongly limited disk space. Initial RX mode: Default mode for FAX reception. Initial b/w TX mode: Default mode for b/w FAX transmission. Initial color TX mode: Default mode for color FAX transmission. Initial SSTV mode: Default mode for SSTV reception and transmission. Max. # of pict./movie: If you are using the program for the automatic generation of weather movies you can limit the maximum number of pictures that will be stored in a movie file by this entry. If the number of pictures in a movie file exceeds the number given here the file will be truncated to this number minus one before a new picture is added to it. The truncation will affect the oldest pictures in the movie, so that the movie will always show the actual weather development. Control codes for R/C demodulators: To enable a fully program controlled mode switching of your interface by the program, JVFAX sends, whenever a change in program mode will take place, a control character to the interface. This character indicates to which deviation or mode (AM/FM/SSTV) the interface has to be switched. Each character comes with the 7th bit set. By this, the interface can differentiate between control characters and picture data. Default setting of these codes are for the latest software revision of the famous "Easyfax" interface, by Ulrich Bangert. Disable XMS-use: on some machine/DOS combination the XMS-memory management that is implemented in JVFAX will not work properly. Typical signs for this are blank screens when zooming or just vertical lines instead of picture contents when printing. In these cases one should set this entry to yes. Be aware that without XMS- management, the preformance of JVFAX will be degraded. Terminate the miscellaneous sub menu by hitting <Ctrl>+<Enter>. JVFAX 6.0, a FAX-/ SSTV-program for IBM PCs and compatibles page 13 Running the program =================== Note: All interfaces used by this program assume that a higher audio frequency corresponds to a "whiter" picture content. For that, your receiver normally has to be tuned to upper sideband when receiving FM-FAX transmissions. If you're receiving in the wrong sideband, the following effects will occur: - automatic phasing won't work - picture is received as a negative If these effects should occur at your first receiving trials, please check for the proper sideband selection. Some basics on the different FAX transmission modes will be explained in the chapter "Frequencies, reception etc." Program start ============= Start the program by entering JVFAX <─┘. The following main menu will appear: ╒══════════════════════════════════════════════════════════════════════════════╕ │ ▀▀██ │ │ ██ ██▀▀▀▀▀ ▄█▀█▄ ██ ██ ▄█▀▀ ▄█▀▀▀█▄ │ │ ██ ██ ██ ██ ▄▄▄▄▄▄ ██▄▄▄▄ ██ ██ ▀█▄█▀ ██▄▄▄ ██ ██ │ │ ▀▀▀▀▀ ██ ██ ██ ██▀▀▀██ ▄█▀ ▀█▄ ██ ██ ▄▄ ██ ██ │ │ ▀█▄ ▄█▀ ▀▀ ▀▀ ▀▀ ▀▀ ▀▀ ▀▀▀▀ ▀▀ ▀▀▀▀▀ │ │ ▀▀▀ │ │ The FAX program for IBM PCs and compatibles Rev: 931001 (c) DK8JV, 1993 │ ╘══════════════════════════════════════════════════════════════════════════════╛ Overlay system in XMS-memory Demodulator: 128 intensity levels on serial port Modulator: 64 intensity levels on speaker Graphics: Standard-VGA 640x480, true intensity display Printer: IBM/Epson 8/9-pins Save-filename: C:\FAX\JVFAX ╒══════════════════════════════ M A I N M E N U ══════════════════════════════╕ │F) FAX N) Change name for save files │ │S) SSTV M) Mode editor │ │H) Show and send pictures T) Screen test │ │O) Movie options P) Printer test │ │D) Date driven FAX reception Q) Quit │ │E) Edit date files C) Change configuration │ ╘══════════════════════════════════════════════════════════════════════════════╛ In the upper two thirds of the screen the program status is shown which can be changed with the configuration procedure described above. In the lower third the menu items are shown. JVFAX 6.0, a FAX-/ SSTV-program for IBM PCs and compatibles page 14 Each menu item can be selected by hitting the character shown left to the ")", by positioning the cursor bar on the item and hitting <Enter> or by double - clicking on the item with the mouse. By invoking JVFAX with the command line parameters /FP or /FS you can skip over the main menu directly to FAX reception with the printer active (/FP) or "save pictures to file" active (/FS). First, an explanation of the less meaningful items: N) Change name for save file: The name entered here is used as a filename for picture storage. The length of this name must not exceed 5 characters, since a current number with three digits and the extension ".GIF" is added automatically. C) Change configuration: To change program configuration just as described above. T) Screen test: A simple screen test to check monitor geometry and correct selection of the graphics driver. P) Printer test: To check selection of correct printer driver and to change the assignment of print patterns to the different intensity levels. A graph appears that shows the current assignment of 16 out of 64 possible print patterns to the 16 intensity levels. This assignment can be changed using the cursor keys. To find out the optimum assignment you can activate your printer by hitting "P". A continuous grey step will be printed that shows the result of your assignment. Hitting "P" again will stop the printout. If using a laser printer you will have to stop printout in order to make the paper come out of the printer. Terminate this procedure by hitting "Q" and answer the question "Save changes" with "Y", if desired. Q) Quit: This is the one and only key that will terminate this program. JVFAX 6.0, a FAX-/ SSTV-program for IBM PCs and compatibles page 15 Fax reception ============= F) FAX reception is invoked from the main menu by hitting "F". An empty screen appears with a small window within: ┌─────────────┬──────────────┬───────────────────────────────────┐ │M):1)Wefax576│ L)pm:120/576 │ │ │A)pt: waiting│ D)ev: 150 │ │ │P(h):N)ormal │ R)otate │ │ │ ├─────────────┼──────────────┤ │ ││ │ │G)rey A(T)C │ L/R T/B│ 1810│ │ │ ││ │ │ 64 off │ <-) ^)│ *) │ │ │││ ││ │ ├────────────────────────────┤ │ ││││ │ │││ │ │P)rinter: off │ │ ││││ ││ │ │││ │ │S)ave to file: off │ │││││││││││││ │││ ││││ │ ├────────────────────────────┤ ┬─┬─┬─┬─┬─┬─┬─┬─┬─┬─┬─┬─┬─┬─┬ │ │Q)uit JV-FAX 6.0 │ B autol(o)ck W │ └────────────────────────────┴───────────────────────────────────┘ *): Current picture resolution. All parameters shown in this window can be changed by hitting the character just before the ")". Changing of some parameters will be disabled when S)ave to disk or P)rinter is on. (P)rinter and S)ave may only be changed when A)PT is in the "waiting" or "SQ.off" state. The meaning of the parameters: M), 0)..9), Alt-0..Alt-9): To select a reception mode. Up to 20 modes can be defined using the mode editor described below. Only modes whose name fields are not empty can be selected. (see also chapter "Mode editor) modes 0..9 can be selected directly by hitting the number keys, modes 10..19 by hitting <Alt>+number keys. JVFAX 6.0, a FAX-/ SSTV-program for IBM PCs and compatibles page 16 L)pm: Transmission speed, expressed in lines per minute. Most stations use 120 LPM transmission speed. Some stations on short-wave, mostly from east European countries use 90 LPM, too. Geostationary satellites such as Meteosat transmit with a speed of 240 LPM. During a FAX transmission the drum speeds on the transmitting and receiving side have to be equal. The number right to the LPM display shows the currently selected IOC. P)rinter,, S)ave to file: To switch on/off printer output or the save to disk option. Can only be changed if APT is in the "waiting" or "Sq.off" state. To have a picture get printed out directly you must set P)rinter to on before the transmission starts. If you have set "Quick save" to yes when configuring the program, saving of pictures permanently to disk can be postponed until the end of a picture. Otherwise, you will have set S)ave to disk to "on" before transmission starts. You cannot activate P)rinter and S)ave to disk at the same time. P(h): To manually start or abort the phasing routine. to achieve a running "in phase" of the transmitting and receiving machines, which means that the left margin of the picture transmitted will be at the leftmost position on the screen of the receiving side, at every start of a FAX transmission a so called phasing or synchronisation signal is transmitted for some seconds. This signal identifies the margin of the transmitted picture. Normally this signal consists of lines with 95% black and 5% white. The white vertical bar generated serves as a marker for the picture margin. Some stations transmit an inverted signal with 95% white and 5% black. The program will use this phasing signal to secure the correct positioning of the picture on the screen and to identify the beginning of the actual picture. Low orbiting satellites don't have a beginning or an end of picture, because they're transmitting continuously. To indicate the beginning picture line they transmit a short tone burst. The programme can "phase" to these bursts, too. This need only be done once at the beginning of a satellite passover. JVFAX 6.0, a FAX-/ SSTV-program for IBM PCs and compatibles page 17 N): Toggles between recognition of normal or inverted phasing signals (See above) or the tone burst synchroisation for the low orbiting satellites. You can toggle between normal, inverted, METEOR, NOAAVIS, NOAAIR and NOAAALL. A)pt: Means Automatic Picture Transmission. Most commercial FAX stations use APT to enable a fully automated unattended reception of the transmitted pictures. Before the transmission of the phasing signal, a so called start tone is transmitted for some seconds, that will be recognised by the receiving unit. Then, the receiving unit switches from standby to operational mode and waits for a phasing signal to appear. At the end of the transmission, another "stop tone" is sent that switches the receiving unit back to standby mode. Different IOCs of the transmitting station can be identified by different APT start tones in weather FAX transmission. In connection with a time table, APT operation makes it possible to selectively receive some desired pictures out of many. APT picture transmission uses the following protocol: First, APT is in the "waiting" state, and nothing will be written to the screen. As soon as a start tone is detected, APT switches to the "running" state, and the phasing routine is activated. (Eventually the correct IOC will be set, derived from the start tone frequency) During the transmission of the phasing signal, the phasing routine determines the correct position of the picture. When the phasing signal ends, the phasing routine will stop and the picture draw routine is enabled that will draw the picture to the screen, store it or print it. During the drawing process the APT routine will check for an APT stop signal. When this is detected, drawing of the picture will stop, eventually the save file will be closed and APT returns to the "waiting" state. The received picture will remain on the screen until it's overwritten by a new one. JVFAX 6.0, a FAX-/ SSTV-program for IBM PCs and compatibles page 18 By hitting the "A" key, you can toggle the program APT state manually. This is useful for the reception of stations not transmitting APT tones. When switching APT manually the phasing routine will not be affected. So, if you want to receive a station that transmits a phasing signal, but no APT signal, you should first switch P(h)ase to on and then set APT to "running". Alternatively you can disable the whole APT routine by hitting the "X" key to replace it with a "squelch" routine. (see below) A(T)C: To switch the automatic tuning control on or off. The functional principles of the ATC are described in a separate chapter. Q)uit: To terminate FAX reception and to return to the main menu. R)otate: If you have missed the phasing signal of a picture transmission you can use this option to have the remainder of the picture written correctly to the screen. Switch APT to running and Phase to off, and watch the picture being displayed. After having written some lines, if the margin of the picture isn't on the left or right side of the screen, hit the "R" key. Now move the cursor being displayed to the edge of the picture and hit <Enter>. The rest of the picture will be written correctly positioned. Using this routine will not affect the storage of the picture to disk. A stored picture can be rotated as a whole afterwards. G)rey: Determines with how many grey levels a picture shall be displayed or stored. ->),<-): To change scan direction You can choose between normal (left to right) or inverse scan direction. Receiving a picture with the wrong scan direction will result in a mirrored image. JVFAX 6.0, a FAX-/ SSTV-program for IBM PCs and compatibles page 19 v),^): Like above, but mirroring of the image will be bottom to top instead of left to right. Can be combined with the above function to rotate a picture by 180 degrees. D)ev: To select the proper deviation for the station being received. You can choose between 150, 300, 400 and AM. Since, with the exception of the "comparator interface", setting of deviation can only be done within the interface, this command is simply passed through to the interface by means of control characters described below. Most short-wave stations use a deviation of 400 Hz, while polar or geostationary satellites will use AM. When in ATC mode, the interface mist be set to twice the deviation of the transmitting station. Deviation means half the difference between the frequency representing white and the frequency representing black. The following commands are not shown in the window: Space key: To switch the window on or off. X): To toggle between APT and squelch mode. When in squelch mode, SQ.on or SQ.off is shown in the window instead of waiting and running. Other than in APT mode the squelch mode monitors for "noise" in the input signal instead of start or stop tones. If there is less than a certain amount of noise in the input signal for more than a given time, this is interpreted just as an APT start tone in APT mode, If for more than another given time there is noise in the input signal, this will be interpreted as a stop condition. This mode can be used preferably for the reception of polar satellites: All activity on the received frequency will be recorded without the need to calculate rising or setting times of the satellites. Note: phasing will be skipped when in squelch mode unless you select NOAAVIS, NOAAIR, NOAAALL or METEOR as phasing mode. ( N) key) F): Turn APT frequency counter on/off: When you hit "F", the currently detected APT tone frequency, preceded by a "F:" is displayed instead of the resolution. Can be used to find out which start/stop tone a station employs. JVFAX 6.0, a FAX-/ SSTV-program for IBM PCs and compatibles page 20 C): Turn on/off calibration display: works exactly like "F", but instead of the APT frequency the current intensity level delivered by the interface is displayed. You can use this for interface alignment etc. O): Freeze ATC on/off: When receiving pictures using the automatic tuning control it can be advantageous to have the ATC run only during the phasing procedure of the transmission. You can achieve this by setting "Enable auto lock when ATC is on" in the configuration menu. This key does exactly the same what the auto lock feature does at the end of the phasing signal. If auto lock is "frozen" then a "autol(o)ck" message appears right below the tuning indicator display. E): Activates the mode editor. Only applicable when APT is in the waiting state. Has the same meaning as the "M" key in the main menu. The mode editor will be described in the next chapter. /: Oblique skew correction: If the received pictures look slanted you can correct this with the following procedure: Receive a picture in a not phased condition, that means that the picture margin should be completely visible somewhere on the screen. With the picture on the screen and APT in the waiting state, press the "/" key. A vertical line appears that can be skewed using the cursor left and right keys. Using <Ctrl> + cursor keys the line cab be shifted without changing its skew. Now simply align this line with the picture margin and hit the enter key. All the following pictures will be received correctly. This procedure can be repeated as often as you like, but normally doing it once will be enough. *: Can be used to toggle the state of the DTR line if the interface is connected to a serial port. (also see "Switch" at the description of the date editor. JVFAX 6.0, a FAX-/ SSTV-program for IBM PCs and compatibles page 21 M) Mode editor: =============== Invoking the mode editor produces the following screen: (JV)-FAX 6.0 mode editor screen ╒══════════════════════════════════════════════════════════════════════════════╕ │ Mode: 5 Ham 288b Alternate mode: 4 HamColor │ │ │ │ IOC: 288 LPM: 240 Resolution: 905 │ │ Deviation: 400 ATC: off Intensity levels: 64 │ │ TX-HW-filt: off RX-HW-filt: off │ │ ____________________________________________________________________________ │ │ │ │ APT-Mode: tone Phasing signal: normal Scan direction: >┐ │ │ │ │ APT start tone frequency (Hz) 675 +/- 15 Min. duration (lines): 5 │ │ APT stop tone frequency (Hz) 450 +/- 10 Min. duration (lines): 3 │ │ ____________________________________________________________________________ │ │ │ │ Display width usage: (%) 100 Printer width usage: (%) 100 │ │ Receive pictures inverted: off Print pictures inverted: off │ │ │ │ Which color palette shall be used: STANDARD JV-Color mode: off │ │ │ │ Execute DOS command: Switch: off │ │ │ │ Use <+>, <-> or <space> to select the mode you want to edit │ ╘══════════════════════════════════════════════════════════════════════════════╛ Hit <Ctrl>+<Enter> to terminate mode editor session To edit a specific mode, first select it by positioning the cursor on the mode number field, then hit the space key until the desired mode name appears in the field right to the mode number. To create a new mode, hit the space key until the name field becomes empty. Now you can enter a name for the new mode in the name field. The other fields have the following meanings: Alternate mode: Select the mode number of an alternate mode here of which the APT start frequency shall be checked in parallel to the start frequency of the edited mode. Serves for the automatic recognition of IOC in weather FAX reception. IOC: Means Index of co-operation. The IOC must be selected according to the IOC of the transmitting station, else the pictures will not be displayed with the correct height/width ratio. JVFAX 6.0, a FAX-/ SSTV-program for IBM PCs and compatibles page 22 LPM: You can choose between different transmission (drum) speeds. Intensity levels: Determines with how many intensity levels a picture is to be stored or displayed. APT mode: You can choose between APT tone or squelch mode. Has been described earlier. Phasing signal: Normally set this to normal. For some stations, like Meteosat, this must be set to inverted. Scan direction: Determines how the picture will be displayed on the screen. Normal scan direction is from left to right and from top to bottom. By changing this field you can have a picture display flipped horizontally or vertically or have it rotated by 180 degrees. APT start tone Frequency, min duration, APT stop tone Frequency, min duration: To enter the tone frequencies of APT start and stop signals. Tone frequencies are entered in the first field, the second field is used to enter a bandwidth. Min duration determines, for how many picture lines the tone signal must be present to be recognised. Enlarging the bandwidth or shortening the min duration value will both make the APT routine more sensitive, but will increase the possibility of the routine being triggered to noise or some patterns that are part of a picture. If bandwidth is set to 0, this mode can be started (or stopped) only by hand. ("A" key) Display width usage: If you receive pictures that are higher than 3/4 of their width these pictures will not fit completely on the screen. To avoid this, you can reduce the display width to such an amount that the picture fits completely onto the screen. If you choose 75% for example, the quadratic Meteosat pictures will fit on the screen. Printer width usage: Same as above, for printer output. Since the printer has no limitation on display height, this will be mainly used to reduce picture size. Which colour palette shall be used: You can enter the name of a colour palette here that has been previously defined in the "Show and send pictures" routine. This will only work if your program is configured for a SVGA 256 colour mode. If you enter a palette name here, this palette will be used when receiving pictures. JVFAX 6.0, a FAX-/ SSTV-program for IBM PCs and compatibles page 23 This puts no limitation on the ability to re-colorize the received pictures afterwards. Alternatively, you can enter here the name of a so called schedule file, which may contain palette name entries for each single picture being received as well as references to picture masks to be overlaid to the pictures received. See chapter: Picture masks for the reception of geostationary satellites. Receive pictures inverted: If on, received pictures will be displayed and stored with black and white inverted. Print pictures inverted: If on, pictures being printed while receiving are printed out inverted in relation to the screen display. Execute DOS command: Optionally enter the name of a DOS command to be executed just before the program switches to this mode. The program to be executed should be fast and should not need too much memory. Switch: when not having selecte a "Comparator type" demodulator, this entry determins the state of the DTR line. Useful to toggle between two receivers etc. Only applicable if your interface is connected to a serial port. You can terminate the mode editor by pressing <Ctrl>+<Enter>. Please regard that you can only edit one mode at the time, that means that after having edited a mode, and before editing another one, you must quit the mode editor and re-invoke it, or nothing will be stored. JVFAX 6.0, a FAX-/ SSTV-program for IBM PCs and compatibles page 24 D) Date driven FAX reception and E) Edit date files: ==================================================== Date driven FAX reception in connection with the APT makes it possible to selectively receive pictures. For this you must first define a "date file", where all the dates for the pictures to be received will be defined. Dates can be entered as occurring once or daily. Every date file may contain up to 96 dates. To edit a date file, invoke the item "E) Edit date files" from the main menu. A screen like this appears: (JV)-FAX 6.0: date file editor ╒══════════════════════════════════════════════════════════════════════════════╕ │ Select one of the date files below to be modified. │ │ │ │ Press <ENTER> to accept or <F2> to create a new one. │ │ │ │ │ │ │ │ │ │ ╒ C:\JVFAX\*.TIM╕ │ │ │ d2.tim │ │ │ │ hugo.tim │ │ │ │ test.tim │ │ │ ╘═══════════════╛ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ ╘══════════════════════════════════════════════════════════════════════════════╛ Hit <CTRL>+<ENTER> to terminate date editor session If there are already some date files defined then you can choose one of them to be edited. To create a new date file, simply hit <F2>. JVFAX 6.0, a FAX-/ SSTV-program for IBM PCs and compatibles page 25 Now, the edit screen opens: (JV)-FAX 6.0: date file editor ╒══════════════════════════════════════════════════════════════════════════════╕ │ File being processed: D2 │ │ │ │╒ yy/mm/dd hh:mm ---mode--- dur --APT--- ovp file ═ │ ││ everyday 00:30 3 Meteosat 5 active 2 D2 ▓ │ ││ everyday 00:58 3 Meteosat 5 active 2 D2 │ │ ││ everyday 01:30 3 Meteosat 5 active 2 D2 │ │ ││ everyday 01:58 3 Meteosat 5 active 2 D2 │ │ ││ everyday 02:30 3 Meteosat 5 active 2 D2 │Select entry with ^,v │ ││ everyday 02:58 3 Meteosat 5 active 2 D2 │ │ ││ everyday 03:30 3 Meteosat 5 active 2 D2 │ <─┘ : edit │ ││ everyday 03:58 3 Meteosat 5 active 2 D2 │ <F2>: add/copy │ ││ everyday 04:30 3 Meteosat 5 active 2 D2 │ <F3>: delete entry │ ││ everyday 04:58 3 Meteosat 5 active 2 D2 │ │ ││ everyday 05:30 3 Meteosat 5 active 2 D2 │ │ ││ everyday 05:58 3 Meteosat 5 active 2 D2 │ │ ││ everyday 06:30 3 Meteosat 5 active 2 D2 │ │ ││ everyday 06:58 3 Meteosat 5 active 2 D2 │ │ ││ everyday 07:30 3 Meteosat 5 active 2 D2 │ │ │╘══════════════════════════════════════════════════════ │ │ │ ╘══════════════════════════════════════════════════════════════════════════════╛ Hit <CTRL>+<ENTER> to terminate date editor session Using the cursor keys you can pick one of the dates in order to change it (<Enter>), to copy it (<F2>) or to delete it (<F3>). If there are no dates in the file, use <F2> to add a new date. When adding or changing a date the following entry mask is used: ╒═══════Date editor════════╕ │ Date: / / │ │ Time: 00:37 │ │ Save-mode: View │ │ Mode: 0 Wefax288 │ │ │ │ APT routine: active │ │ Max. duration: 4 │ │ Time overlap: 2 │ │ Filename: JVFAX │ │ │ │ Execute DOS command: │ │ │ │ Exit to DOS: no │ │ │ │ │ │ Update clock: inactive │ ╘══════════════════════════╛ JVFAX 6.0, a FAX-/ SSTV-program for IBM PCs and compatibles page 26 The meaning of the fields is as follows: Date: If this date shall occur only once, you must enter a valid date using the picture "yy/mm/dd". For dates that are to occur daily, all sub fields must be blanked. Time: Enter the start time of the picture to be received here. This time entry must correspond to your computers time, i.e. if your computer clock is set to UTC, for example, all times must be entered in UTC. Save-mode: Determins what's going to happen to the picture received: If you choose "Save", the received pictures will be stored as a file using the file name given in the file name field, with a numeric extension being added to it. "Movie" will add the picture received to the movie file given under "file name" in the date editor. If a movie file contains more pictures than given in the "Maximum # of pictures / movie" field of the miscellaneous menu, the movie will be trimmed to this number minus one, before a new picture will be added. Always the newest pictures will remain in the movie. "Print" works the same way as Save, the only difference is that the picture will be printed instead of being saved to disk. By choosing "View", the picture will only be displayed on the screen and remain there until the next date becomes active. Mode: Use +, - or <space> to select the proper mode for this date. APT routine: If you set this field to inactive, acquisition of pictures will start immediately after having reached the time given above, disregarding all APT tones and phasing signals. Acquisition will last for the period given in the Max. duration field. Max. duration: Determines the maximum duration of a picture acquisition. After this time has passed, counting from the reception of an APT start signal (when APT routine is "active") or from the time entered above (when APT routine is "inactive"), acquisition will be terminated anyway, even if no stop signal has been received. Time overlap: If APT routine is "active", an APT start tone has to be detected within this period, or the reception for this date will be cancelled. This field makes possible overlapping dates: If the acquisition of a previous picture will terminate after the time of the following picture has already been reached, the routine will wait until the time entered in the Time: field plus the time given in the time overlap field for the new picture to start before this date will be cancelled. JVFAX 6.0, a FAX-/ SSTV-program for IBM PCs and compatibles page 27 Filename: Enter an filename that will be used for picture storage or to determine to which movie the received picture shall be added. Maximum length of the filename is limited to 5 characters. Execute DOS command: Enter the mane of a program to be executed right after picture acquisition has terminated. You can use this for example, if you have a receiver that can be remotely set to a specific frequency by your computer. As in the case of the execute DOS command option in the mode editor, the program to be run should be fast and short. Exit to DOS: If you set this field to yes, operation of the JVFAX program will be terminated at the end of the picture acquisition for that date, and control will be give back to DOS. Update clock: Only applicable when receiving METEOSAT pictures. Since thes pictures are sent very precisely in time, the computer' clock can be synchronised to the METEOSAT transsmissions. Please be aware that only the seconds are synchronised, so that clock deviations of more than +/- 30 seconds cannnot be corrected. Do not activate this option when receiving other than geostationary satellite transmissions, or your computer clock will be set to false values. Terminate the date editor with <Ctrl>+<Enter>. To do date driven FAX reception you must invoke item "D) Date driven FAX reception" from the main menu. First, you must select a date file to be processed: (JV)-FAX 6.0: date driven FAX reception ╒══════════════════════════════════════════════════════════════════════════════╕ │ Select one of the date files below. │ │ │ │ Press <ENTER> to accept. │ │ │ ╘══════════════════════════════════════════════════════════════════════════════╛ ╒ C:\JVFAX\*.TIM╕ │ d2.tim │ │ hugo.tim │ │ test.tim │ ╘═══════════════╛ JVFAX 6.0, a FAX-/ SSTV-program for IBM PCs and compatibles page 28 After having taken your choice you will be back in the main menu and you can proceed doing anything with the program like before. (e.g. view movies) As an information that date driven reception is active, an additionally bottom line will appear in the main menu that tells you the actual time, the time of the next date and about what will happen when the next date will be reached. 20 seconds before the next date comes, the program will suspend its current action, switch to receive mode and start picture acquisition. When the transmission has completed, it will return to the previously suspended action. You can run the program directly in Date driven reception mode by adding some command line parameters when invoking the program. For that, start the program this way: JVFAX /D Filename Filename must be replaced by the name of the date file to be activated. /D means "Date driven reception. JVFAX 6.0, a FAX-/ SSTV-program for IBM PCs and compatibles page 29 Show and send pictures ====================== This menu item serves for the viewing and editing of stored pictures. For radio amateurs, there is an additional transmit option. You can do zooms with freely selectable width/height ratio; zoomed portions of a picture can be stored as unique pictures. When invoking this menu item, the following screen appears: ╒══════════════════════════════════════════════════════════════════════════════╕ │ ▀▀██ │ │ ██ ██▀▀▀▀▀ ▄█▀█▄ ██ ██ ▄█▀▀ ▄█▀▀▀█▄ │ │ ██ ██ ██ ██ ▄▄▄▄▄▄ ██▄▄▄▄ ██ ██ ▀█▄█▀ ██▄▄▄ ██ ██ │ │ ▀▀▀▀▀ ██ ██ ██ ██▀▀▀██ ▄█▀ ▀█▄ ██ ██ ▄▄ ██ ██ │ │ ▀█▄ ▄█▀ ▀▀ ▀▀ ▀▀ ▀▀ ▀▀ ▀▀▀▀ ▀▀ ▀▀▀▀▀ │ │ ▀▀▀ │ │ The FAX program for IBM PCs and compatibles (c) DK8JV, 1993 │ ╘══════════════════════════════════════════════════════════════════════════════╛ ╒═══════════ D:\WASSER\*.GIF ═══════════ │ .. <dir> 2/07/92 11:51p ▓ │ afsk.gif 223k 5/18/92 6:40p │ │ d2___001.gif 326k 5/26/92 5:30p │ <F2>: Info │ jvfax044.gif 213k 5/17/92 8:04a │ │ jvfax045.gif 269k 5/17/92 8:08a │ <F3>: Change drive/path │ jvfax046.gif 253k 5/17/92 8:12a │ │ jvfax047.gif 264k 5/17/92 8:15a │ <F4>: Delete file │ jvfax048.gif 272k 5/17/92 8:19a │ │ jvfax049.gif 246k 5/17/92 8:22a │ ╘═══════════════════════════════════════ Select a file with <ENTER>, <ESC> to abort Use the cursor bar to select a picture file. <Enter> will show the picture while <F2> will give some additional information on this file. Use <F3> to change to another drive or to quickly change the directory. JVFAX 6.0, a FAX-/ SSTV-program for IBM PCs and compatibles page 30 <F4> is to erase files. After hitting the <Enter> key, picture display will start. You can interrupt the building up of the picture on the screen at any time by pressing <Enter> again. Every picture will be displayed in a way that it will fit completely onto the screen. When the picture has been displayed completely or after you have interrupted picture display by hitting <Enter>, a menu line will appear at the bottom of the screen that will inform you about the available options. You can switch on or off that menu line anytime by hitting the space bar. Use E)dit to change picture orientation. Furthermore, you can invert the picture or export it in TIF-Format (24 bit, uncompressed) or in GIF87a, if it was stored in GIF89a. If there's enough XMS memory installed in your computer, the picture can be rotated by 90 degrees. By using the R)otate option you can shift the picture horizontally. This is useful if phasing did not work properly when the picture was received. Z)oom shows a little frame that can be moved over the screen with the cursor keys. Frame size can be changed with +, -, x or y. Hitting <Enter> will show the framed portion magnified to full screen size. Besides being viewed, this zoomed portion of a picture can be saved or transmitted. JVFAX 6.0 uses the well known GIF format for picture storage. This greatly reduces disk storage requirements. Many GIF viewers or other programs to process GIF pictures are available on the PD and shareware market. If JVFAX is running in 256 colour mode, you can use "Pa(I)ette" to colorize your pictures, or you can change the contrast or intensity of pictures. You can use the (H)istogram equalization to enhance satellite pictures, especially NOAA pictures. Just play around a bit with this option to get a feeling of how it works. JVFAX 6.0, a FAX-/ SSTV-program for IBM PCs and compatibles page 31 For radio amateurs, there is a transmit option, that can be used to transmit complete pictures or zoomed portions of a picture. When you hit the "A" key, you are first asked if you want to transmit in FAX or SSTV. Then, a small menu appears that shows the modes available for transmission. After having chosen the desired mode you can enter some text that will be overlaid to the picture. (Maximum text size is 24 columns * 8 lines) Text entry can be skipped by hitting <Escape>. Terminate text entry with <Ctrl>+<Enter>. After that, a small frame shows the size and position of the text on the picture. Use + or - to resize and cursor keys to reposition. S)tyle changes the appearance of the text. When all looks good, hit <Enter> and the transmission will start. While transmitting, a cursor line shows the proceeding of the transmission process. You can abort transmission by hitting any key. Each transmitted picture is preceded by a small header that contains a grey step, a small program logo and your Callsign within. When transmitting in SSTV, the pictures will be cropped temporarily before transmission to guarantee for a 4:3 width to heigth ratio. The (F)ax and Sst(v) keys are hotkeys that directly switch to FAX or SSTV recepion. When Q)uitting, the program returns to the "Show..." routine. Good for interactive QSO's. JVFAX 6.0, a FAX-/ SSTV-program for IBM PCs and compatibles page 32 MOVIE Options ============= Invoking this item opens a sub menu that has three items: "S) Show movie", "A) add pictures to a movie" and "D)efine zoomed area for movie. S) Show movie will come up with a file selection menu from which you can choose which movie shall be replayed. To enable a fast display rate when showing movies, JVFAX tries to establish as many RAM buffers as possible in XMS and conventional memory. (EMS memory will not be used yet) If you are running an XMS memory manager such as HIMEM.SYS, you should tell it to provide a sufficient number of XMS handles. In the case of HIMEM.SYS this is done by adding the parameter "/numhandles=99" to the HIMEM.SYS device line in CONFIG.SYS. If you're using HIMEM.SYS, the entry in CONFIG.SYS should look as follows: DEVICE = c:\HIMEM.SYS /numhandles=99 If the /numhandles parameter is omitted, HIMEM.SYS will only provide 32 handles, of which DOS 5.0 will use two in case you're using the "DOS=UMB" option. After having chosen the desired movie, JVFAX will first look if all the pictures in the movie will fit in the buffers. If so, the movie will be loaded and display will start. If not, you will be asked if you want to see all of the pictures in the movie (dynamic reload) or if you prefer to see only the last pictures that will fit in the buffers (fully buffered mode). The dynamic reload mode will be much slower than the fully buffered mode, but on machines with limited RAM memory this is the only choice to watch longer movies. While the movie is being displayed you can change display speed with the "+" and "-" keys. Hitting the "Pause" key will temporarily halt the movie; hit any key to restart it. The actual maximum display rate depends on your PC's speed and in the case of the "dynamic reload mode" on your hard disks speed. Movies are normally shown with the palette that was active when the last picture of the movie had been received. While a movie is being displayed, you can switch to S)ingle step and then step forth or back through the movie using the cursor keys. In this mode, yuo can also delete single frames off the movie. A)dd pictures to movie file enables you to manually create movies. Normally, you will not need this option unless you're planning to create a kind of "slide show". All movie pictures are displayed using a resolution of 640 by 350 dots in 16 colour mode. Since dithering is used, a total of 64 intensity levels will be displayed. This mode is the only mode that works on any VGA card. When using a graphics card based on the ET4000 chipset, you can alter- natively select a "HIRES" movie with a 640x480x256 resolution. This will only work if you have sufficient XMS memory. D)efine zoomed area for movie: ust this option when you wish only a zoomed portion of a satellite picture to be assembled to a movie file: First, receive and store the satellite picture format of interest, then use this menu item to zoom out a portion of this picture. you can then D)efine this area as the one of which a movie will be automatically generated. JVFAX 6.0, a FAX-/ SSTV-program for IBM PCs and compatibles page 33 SSTV: ===== When invoking S)stv from the main menu, a screen will appear that looks like this: ┌────────────────────────┐┌────────┐ │ ││ │ │ ││ │ │ ││control/│ │ ││ │ │ display ││ status │ │ ││ │ │ area ││ │ │ ││ area │ │ ││ │ │ ││ │ │ ││ II │ │ ││ │ │ ││ │ └────────────────────────┘└────────┘ ┌────────────────────────┐ │ │ │ control area I │ │ │ │ │ │ │ └────────────────────────┘ In the left half of the control area, a list of all available SSTV modes is shown. You can choose one of these modes with the cursor keys. The following commands are available: (V)ertical mode: can be selected between -normal: the program will wait for a vertical sync pulse, write a picture and the will then wait for the next vsync pulse. -auto stop: like above, but after having received one picture the program will stop and will not receive any further pictures until it will be reset to the run condition by use of the (R)un or (S)top key. -run free: all vertical sync pulses will be ignored, received lines will be displayed continuously. If the bottom of the display area is reaced, display will start from the top again. JVFAX 6.0, a FAX-/ SSTV-program for IBM PCs and compatibles page 34 (H)orizontal mode: -normal: all horizontal sync pulses will be evaluated and used for display synchrinization. -auto free run: if the horizontal sync pulses show a precise timing, the program will switch to a free run mode in which further sync pulses will be ignored. By this, QRM or noise cannot garble picture synchronization, just like when receiving FAX transmissions. the free run mode will stop automatically when the end of the display area is reached in order to enable synchronization to the next picture. -free run: absolutely no sync pulses are evaluated. Useful for test purposes. (S)top: hitting this key "freezes" the picture reception. Nothing will be received until you press (S) again or you press the (R) key, instead. When the program was stopped, a "Stopped!" message appears in the control area II. If you terminate this condition by hitting (S), the program will wait for the next vsync; if you use (R) instead, display will start immediately. (R)un: to terminate the "stopped" condition. when being pressed while display is in progress, display will restart at the top of the display area. (P)alette sequence: in some modes, the color palette can be toggled by using this key. (A)uto sav(e): Hitting (A) switches auto save on or off. If autosave is on, everytime when a picture has been written, it wil be saved automatically. Filenames are given automatically, just like when receiving FAX transmissions. By hitting (E), you can save whatever is on the screen under a file name of your choice. For the storage of SSTV pictures, a foxed format of 340 by 256 pixels is used. Color is reduced to 256 different values by using the same color reduction scheme as in the reception of JVCOLOR pictures. Saving of SSTV pictures will not work if your computer does not have sufficient XMS memory. If auto save is on, the "(A)uto" in the control area I will be shown inverted. All pictures will be saved in GIF format. You should choose a high resolution graphics mode for the SSTV display, because the pictures are shown dihered whilst reception. JVFAX 6.0, a FAX-/ SSTV-program for IBM PCs and compatibles page 35 (4),(6) und (1),3): Temp. slant correction: with these keys, you can temporarily alter the horizontal line scanning frequency for picture reception. Normally, you will not need use this option, but it allows to use the auto free run mode also with stations that aren't transmitting with the correct line frequencies. To achieve that, have the station that you wich to receive pictures from transmit some pictures while you're receiving in horizontal free run mode. While receiving, use the above keys to alter the line frequency until the pictures are no longer slanted. After that, you can receive further pictures of the other station in auto free run mode. Caution: ======== this is no replacement for the oblique skew correction described above. In any case you will have to do the oblique skew correction in order to transmit your own pictures without being slanted. JVFAX 6.0, a FAX-/ SSTV-program for IBM PCs and compatibles page 36 JV-Color, a color fax transmit/ receive mode ============================================ JV-Color is a line sequential transmission mode for color pictures. Most commercial FAX users transmit color pictures as three subsequent colpr excerpts, according to the CMY color model. For amateur radio use this is not a quite satisfying procedure beause you has to receive the three single pictures completely before you can start to put them all together. The color mode implemented in this program uses a line sequential transmission similar to sole color SSTV modes. This makes possible to view the pictures while they are being received. I called this mode "JV-Color", but I do not claim having invented it. (as far as I know, some trials in line sequential color FAX transmissions by radio amateurs have been done before, and there is actually nearly no difference to color-SSTV) The new mode works as follows: APT start tone transmission and phasing signal transmission is done as usual in b/w picture transmissions. The end of the phasing signal is indicated by the transmission of an inverted phasing line. From now on, every picture line is being transmitted as three single lines of which the first represents the red, the second the green and the third the blue excerpt of the original line. By that, the time required by color transmissions is thrice the time for b/w transmissions, as long as all other parameters remain unchanged. On the receiver side, each three lines are combined to a single color-line, and are displayed on the screen using a dithering technique. While receiving, the number of possible colors is reduced to three time five bit which equals to about 32,000 different colors. In order to get the picture stored in a GIF file format that allows only for 256 different colors, a color reduction is done after the reception of a complete picture using a modified median cut algorithm. (Color display of color pictures within JVFAX works only on SVGA graphic cards in 256 color mode) JVFAX 6.0, a FAX-/ SSTV-program for IBM PCs and compatibles page 37 Special cases when receiving JV-Color pictures: =============================================== 1). a picture has been received in color mode, but has been transmitted in b/w: - the last picture that has been received in color mode ist stored in the file "RAWCOL.GIF" without having been processed as a color picture. In this special case it's just the b/w picture. 2). a picture has been received in b/w mode, but was transmitted in color mode: - if the picture had been stored, it can be converted to a color picture using the C)onvert to JV-Color option of the Show.../ Edit.. menu. 3). you start recieving a picture, but the phasing signal had already terminated: - While transmission is in progress, you can use the R)otate function to put the rest of the picture into the correct position on the screen. After that, you can use the "V" key to toggle the sequence of the RGB- palette, if the colors should be wrong. If you do all this before the tramsmission ends, the picture will be stored in the correct position and with the correct colors when the color reduction procedure starts. Achievable resolution of JV-Color transmissions: ================================================ If all other parameters are kept unchanged, a color transmission takes three times the time on a b/w transmission Because most of us are rather impatient people, I defined a new mode for color FAX transmissions with 360 lpm and an IOC of 204. Against a b/w transmission with IOC 288 and 240 lpm, transmission time increses by a factor of about 1.3. The resolution obtainable with this mode is about 640 dots per line. (Actually, horizontal resulution is a little bit smaller due to bandwidth limitations on the tranmission path) As a matter of course, you can change to lower drum speed and higher IOCs, if you want to transmit pictures with even more resolution. Please reduce drum speed when changing to higher IOCs because else the computer might hang due to excessive pixel interrupt rates. JVFAX 6.0, a FAX-/ SSTV-program for IBM PCs and compatibles page 38 Additional control keys for JV-Color transmission / reception: ============================================================== 1.) in the mode editor, a new menu item has been estabilshed to set a specific mode to either color or B/W as default. 2.) when receiving fax pictures: J): toggles between b/w and color fax reception. can be changed only when APT is in the "waiting" state. V): to change the sequence of the RGB color palette, if a picture is received with a wrong color assignment. 3.) in the E)dit sub menu of the Show... pictures routine: C)onvert: converts a JV-color picture that has been received in b/w mode into a 256 color GIF-picture. V): to change the RGB sequence of the color palette, as described above. 4.) in the "miscellaneous menu": The menu item "Initial TX mode" has been splitted in two items - Initial B/W TX mode and - Initial COLOR TX mode The initial B/W TX mode is the default mode for the transmission of pictures that don't have colors (i.e. a palette that has only grey shades) while the other mode is the default for the transmission of color pictures. JVFAX 6.0, a FAX-/ SSTV-program for IBM PCs and compatibles page 39 Something about FAX transmissions: ================================== Modulation type of transmission: 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. Press stations sometimes use a deviation of 300 Hz, too. Such a modulation can be achieved by direct frequency modulation of a transmitter or by frequency modulating an audio sub carrier (mostly 1900 Hz) and then modulating a SSB transmitter with this sub carrier. On the receiver side, you can use direct frequency demodulation, but this will work only if your receiver demodulator is capable of handling frequencies down to the DC level. More preferably one receives the FAX signals with a SSB receiver that, at it's audio output, delivers a FM-modulated audio sub carrier. (Just the opposite as on the transmitting side) 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. For each distinct intensity level the interface must deliver a binary coded value that computes to (n= number of intensity levels that the interface can deliver) n Intensity := (audio frequency - freq. for black) * ---------------------------------- (freq. for white - freq. for black) JVFAX 6.0, a FAX-/ SSTV-program for IBM PCs and compatibles page 40 If you are using the comparator type interface, frequency measurement is done by software. The program "counts" the length of the periods of the audio frequency by means of the programmable interval timer that can be found in every PC. Each edge of the audio signal generates an interrupt that invokes a small routine that counts the number of timer ticks that have occurred since the last interrupt. Because interrupt response times can vary significantly, this computation of the audio frequency isn't very precise. That results in some "noise" in the received pictures, where the amount of noise depends on many factors such as processor speed, type of CPU, etc. Running a memory manager such as EMM386 on some machines will result in nearly completely jammed pictures. In such cases, the only solution is to disable the memory manager operation when running JVFAX. The better solution, of course is to use a more sophisticated interface, that frees the computer from the need to measure the audio frequency itself. Polar satellites as well as geostationary satellites are using another modulation method for signal transmission: A FM transmitter is modulated with an audible sub carrier (mostly 2400 Hz), of which the amplitude is modulated by the video signal. That's why this is called AM-FAX. One receives these transmission with a FM receiver. The audio output of the receiver must be rectified to regain the original video signal. This demodulated signal will be fed to an A/D converter that can be connected to the computer. JVFAX 6.0, a FAX-/ SSTV-program for IBM PCs and compatibles page 41 How the ATC works: ================== The automatic tuning control (ATC) implemented in this program for the reception of FM-FAX has been completely realised by software. The only hardware requirements are that the interface must be able to deliver a signal of which the intensity levels correspond to twice the frequency range of the signal actually received. So, if you want to receive a station transmitting with a deviation of 400 Hz, your interface must be set to 800 Hz deviation. Using the ATC results in the loss of one bit of intensity resolution, i.e. in order to resolve a signal with 64 (6 bits) intensity levels, your interface must be able to deliver at least 128 intensity levels (7 bits). When ATC is on, the program calculates by means of signal averaging the center (audio) frequency of the received signal and assumes, that the actual signal spectrum is within the range of (center frequency +/- deviation of transmitted signal) Frequency drifts up to +/- half the deviation of the transmitted signal will be completely compensated. As long as none of the two small vertical lines appearing below the frequency spectrum display will not reach the left- or rightmost positions, the ATC will be able to compensate frequency drifts. Phasing to low orbiting satellites ================================== As described above, low orbiting satellites continuously send scan lines without a definite picture start or end. To indicate the start of a new scan line a short tone burst is transmitted. JVFAX can phase to these bursts. For this, some modes (6,7,8,9) are predefined. Syncronization is done only once at the beginning of a satellite passover since the tone burst recognition routines are quite time consuming. To have the routine to work properly, APT must be set to squelch mode, and the picture resolution, as predefined, must not be changed. The synchronization routine is relatively immune to noise, but without a squelched AF output the end of a satellite passover cannot be detected. Using date driven reception elimitates the need of a squelched AF output, because a "maximum duration" value for a passover can be set. If you're using a synchroneous interface, the data rate must be at least 4800 pixels/s. JVFAX 6.0, a FAX-/ SSTV-program for IBM PCs and compatibles page 42 Picture masks for the reception of geostationary satellites =========================================================== When receiving weather pictures, the low contrast between sea and land is often a problem if you want to colorize the pictures. If you're receiving pictures of geostationary weather satellites such as Meteosat, there's a simple solution to this problem. While a picture is being received, a mask file is overlaid to the incoming data. By this, the intensity levels are e.g. shifted to another value everywhere in the picture where it is supposed to be land. By coosing an appropriate palette one can then colorize the land and the sea areas of a received picture fully independently. In order for this to work properly, for every picture scenery to be received one needs an appropriate mask file. Furthermore one needs a schedule file which tells the program about what picture is being transmitted at a given time and what mask is to be overlaid. The name of this schedule file must be entered in the palette name field of the mode editor screen. A schedule file must have the name extension .SCH. It's a plain ASCII file with the following structure: Each single line is composed of hhmmNNNNNMMMMMMMMPPPPPPPP hhmm: Time of transmission (normally UTC) NNNNN: name of the picture to be received MMMMMMMM: name of the mask file assigned to this picture format PPPPPPPP: name of a color palette to be used for this picture The mask files are simple bi-level .GIF files which must have the same resolution (size) as the picture to be received. Schedule files for Meteosat channel 1 & 2, some mask files and an appropriate palette file are included in the JVFAX package. Of course, these manipulations will not add any additional information to the pictures, they just look better.... JVFAX 6.0, a FAX-/ SSTV-program for IBM PCs and compatibles page 43 "Simplest" interface circuit ============================ Here follows the circuit of the "simplest" comparator type interface, that requires only a few parts, but doesn't give superior performance. You can use the "Hamcomm" interface (see below) as well. RS232 Pins (25-pin receptacle) 100 nF 741 1N4148 ┌──────┤─────O RTS 4 ││ 3 │\ │7 O─────┤├───█─────────┤+\│ ││ │ │ \ 6 AF in │ │ >────────────O DSR 6 │ 2 │ / O───┐ │ ┌────┤-/│ │ │ │ │/ │4 ─┴─ ┌┴┐ │ └──────├─────O DTR 20 │ │ ─┴─ 1N4148 47k │ │ └┬┘ │ ┌─────────────O GND 7 ─┴─ ─┴─ The 741 operates as a limiting amplifier with full free-run amplification. It forms the audio frequency to a rectangular wave form with RS232 compatible level. Power is supplied from the computer via DTR (-) and RTS (+). JVFAX 6.0, a FAX-/ SSTV-program for IBM PCs and compatibles page 44 Some SVGA modes: ================ To facilitate the configuration of JVFAX to your specific graphic card, here the register values for some SVGA cards: XP means dots per line, YP lines per picture and ASP screen aspect ratio. A): 16 colour modes: AH AL BH BL XP YP ASP GENOA Super-EGA Hires 0 79h 0 0 800 600 10000 SAMPO-Mira VGA (Taiwan) 0 64h 0 0 800 600 10000 ATI-VGAWONDER 0 54h 0 0 800 600 10000 " " 0 53h 0 0 800 560 10714 ELT VGA PLUS 16 0 58h 0 0 800 600 10000 Paradise Professional VGA 0 58h 0 0 800 600 10000 VIDEO 7 FASTWRITE 6Fh 05h 0 62h 800 600 10000 (and other Video- 6Fh 05h 0 61h 720 540 10000 seven/VEGA cards) 6Fh 05h 0 60h 752 410 13756 EIZO MDB10 0 29h 0 0 800 600 10000 MVGA/TVGA 0 5Bh 0 0 800 600 10000 JVFAX 6.0, a FAX-/ SSTV-program for IBM PCs and compatibles page 45 B) 256 colour modes: Chipset AH AL BH BL XP YP ASP TSVGA ET4000 0 30h 0 0 800 600 10000 (and others ET4000 " 0 2Eh 0 0 640 480 10000 based cards) " 0 38h 0 0 1024 768 10000 VIDEO 7 FASTWRITE Video seven 6Fh 05h 0 67h 640 480 10000 (and other Video- " 6Fh 05h 0 69h 800 600 10000 seven/VEGA cards) Paradise Profess. Paradise 0 5Fh 0 0 640 480 10000 " " " 0 5Ch 0 0 800 600 10000 Cards with Trident Trident 0 5Dh 0 0 640 800 10000 chipset (TVGA, " 0 5Eh 0 0 800 600 10000 MVGA...) " 0 62h 0 0 1024 768 10000 Genoa cards Genoa 0 5Ch 0 0 640 480 10000 " 0 5Eh 0 0 800 600 10000 Cards with OAK OAK 067 0 53h 0 0 640 480 10000 chipset " 0 54h 0 0 800 600 10000 VESA VESA 4fh 02h 01h*) 01h*) 640*) 480*) 10000 " 4fh 02h 01h*) 03h*) 800*) 600*) 10000 *)for further VESA modes see manual of your graphics card. The VESA mode number is always entered in the register pair BHBL. JVFAX 6.0, a FAX-/ SSTV-program for IBM PCs and compatibles page 46 Frequencies, reception etc. =========================== Frequencies of some FAX stations: Freq.(kHz) Stn. LPM MOD HUB remarks ------------------------------------------------------------------ 117.4 DCF37 (DWD) 120 576 150 charts (Air) 134.2 DCF54 (DWD) 120 576 150 charts/Meteosat 3855.0 DDH3 (DWD) 120 576 400 charts (ship) 4782.0 GFE21 (Bracknell) 120 576 400 charts 7880.0 DDK3 (DWD) 120 576 400 charts (ship) 14230.0 +/- 5 kHz diverse 400 Amateur FAX/SSTV 3730.0 +/- 5 kHz " " " " " 144.700 MHz " " Amateur FAX (Germany) Just for example. Please be aware that in many cases the reception of commercial services is not free and that you must be authorised by these services to receive their transmissions. However, the reception of most weather chart transmitters as well as the reception of the polar orbiting satellites (NOAA and METEOR) is free. FM-FAX transmissions should be received using a SSB-receiver in upper sideband position. Normally you will have to tune in a frequency that is 1.9 kHz below the frequency given in frequency lists. This does not apply, if your receiver has a special "FAX" reception mode. In that case, simply tune in the frequency listed. Since the accuracy of the frequency display on many receivers is not too high, you will eventually have to do some fine tuning before you will obtain satisfying results. A problem arises when receiving FAX transmissions with a receiver that can only be tuned in coarse frequency steps such as 100 Hz. Using the ATC facility of the JVFAX program could be a solution on this. JVFAX 6.0, a FAX-/ SSTV-program for IBM PCs and compatibles page 47 Tuning in a weather chart station is not difficult when you keep in mind that most parts of such a chart are white. Favourably you first tune in a frequency somewhat higher than the correct one, (this results in lower audio frequencies) and then decrease the receiving frequency slowly until the spectral maximum shown in the tuning indicator just reaches the right margin. AM-FAX transmissions must be received using a FM receiver. In AM-FAX, a FM transmitter is modulated with an AM modulated sub carrier. (mostly 2400Hz) The amplitude of this AM sub carrier contains the intensity information of the picture. Use your receiver's AF volume knob to optimise picture contrast. JVFAX 6.0, a FAX-/ SSTV-program for IBM PCs and compatibles page 48 Disclaimer ========== I shall not be liable for any direct, indirect, consequential or incidential damages arising out of the use of this software. Using this software for the reception of some transmissions as well as the reception of these transmissions itself might be illegal. I shall also not be liable for any consequeces arising out of such illegal acts. Copyright notes etc. ==================== This program is neither shareware nor public domain. JVFAX is the Copyright property of Eberhard Backeshoff, DK8JV. (c) 1993 by Eberhard Backeshoff, Obschwarzbach 40a, D-40822 Mettmann, Germany. You have the right to use this program for non commercial purposes without further permission. You can copy it and share it as long as you don't charge any money for it other than the cost for the transfer media, not exceeding the equivalent of $4. Any commercial distribution without the w r i t t e n p e r m i s s i o n of the author is strictly prohibited. If you like this program you should write me to give me some feedback. Enclosing an amount of money at choice to support program development will be highly appreciated. Send your letter to the above address. The Graphics Interchange Format(c) is the Copyright property of CompuServe Incorporated. GIF(sm) is a Service Mark property of CompuServe Incorporated. JVFAX 6.0, a FAX-/ SSTV-program for IBM PCs and compatibles page 49 When copying the program the following files must be included: JVFAX.EXE (programm) JVFAX.DOC (German documentation) ENGLISH.DOC (English documentation) D2.TIM (Sample file for date driven FAX reception) MASK????.GIF (mask files for Meteosat receptionn) (19 total) CH1.SCH (Schedule-file for Meteosat channel 1) CH2.SCH ( " " " " " 2) SPECIAL.PAL (Palette for Meteosat reception with picture masks) AM_FM1.GIF - (Sample demodulator circuit for 256 grey) AM_FM6.GIF (levels AM/FM) AM_FMENG.DOC (Documentation to the above schematics) AM_FMDEU.DOC ( " " " " " ) MODULAT.GIF (Sample modulator circuit) INTERF.DOC (description of the various interface types) (supported by JVFAX, and addresses of german) (interface dealers) The program as well as the .DOC files must not be modified in any way, copyright notes must not be removed. Any commercial use of this program as well as a distribution of this program by shareware dealers is prohibited. Distribution via mailboxes and computer networks is free as long as the files mentioned above will remain complete. The name "JVFAX" should be maintained in case the files are packed to an archive. Companies and single persons who want to sell hardware that co-operates with this program are allowed to distribute the program together with their hardware, if they get my written permission. I reserve to charge fees, e.g. on a per disk base in such cases. When giving this software as an add-on to some hardware, it must be clearly pointed out by the seller that having got the software when purchasing the hardware doesn't mean that anything has been paid for the software. ║ Permissions that I gave concerning the distribution of former FAX/JVFAX ║ versions do not automatically apply to this version 6.0. ║ Please write again to get an explicit permission for the distribution of ║ this version. Furthermore, with th availability of this program version, ║ I withdraw all permissions for the distribution of former versions of JVFAX. Program users be aware that the acquisition of this program together with some hardware doesn't mean that you have bought it. Even in such a case all copyright notices given above are fully valid. JVFAX 6.0, a FAX-/ SSTV-program for IBM PCs and compatibles page 50 As you can see from the above notes, you don't have to pay anything to get or to use this program. However, if you should like this program and should use it frequently then you should consider to promote the authors eagerness for further program development by some kind of acknowledgement. Suggestions and criticism are always welcome, but I cannot promise any further development of this program, since I have to do it all in my leisure time. I will do my best to keep this program up to date, but my family always has higher priority. If new program versions should be available, I will try to make this public, e.g. by packet radio. If in doubt if there's a new version, just ask..... Let me say thank you to the numerous persons that with their suggestions and criticism made the program be what it is today. Finally, have fun using this program and always good pictures. For further questions, you can contact me via phone, but please use this only in "cases of emergency"; my family will appreciate that. Or, simply send a telefax to my phone number. Mettmann, october 1993 Eberhard Backeshoff DK8JV Obschwarzbach 40a D-40822 Mettmann Germany Phone/FAX: +49 2058/4684 (please only between 1800 and 1900 CET/CEST)