Epson Multi-mode Data Controller MFJ-1278B Benutzerhandbuch

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MFJ-1278B MULTI-MODE                                     BASIC OPERATION 
Coding: If, prior to unbiasing, the value of the data byte is an ASCII p, q, or r, then the 
received byte is a sync byte. Otherwise, the received byte contains actual display information 
as described above. The color level of each pixel contain in the data byte is given below: 
 
000                                 001                                    110                                          111 
white                        lightest grey                      darkest grey                             black 
 
NOTE: If the data byte is NOT a sync byte, you must remove the 30H bias BEFORE 
extracting the pixel information. 
 
For example, if an ASCII '9' is received, then the following steps should be taken: 
 
1. Remove bias:   
 
39H-30H = 9H 
2. Extract pixel information: 
aaa = 001 bbb = 001 
3. Display two pixels of lighest grey level. 
 
If an ASCII 'p', 'q', or 'r' is received, then process the byte as a sync tone. 
Saving SSTV Pictures to Disk 
When the PRINTGRA command of the MFJ-1278B is ON, SSTV pictures received will be 
sent to the graphics printer attached to the printer port.  If  PRINTGRA is OFF, the MFJ-
1278B will direct the picture graphics, in raw data format, to the user's terminal through the 
RS-232C port of the MFJ-1278B.  If your terminal program allows you to save a file to disk, 
then you can save the picture on disk and re-transmit it later. 
Terminating SSTV Printing 
Printing of an SSTV picture can be terminated at any time during the printing.  User will type 
"ESC" then CTRL-C.  Printing will stop and the MFJ-1278B  will return to command mode. 
Transmitting SSTV Pictures 
The MFJ-1278B is capable of transmitting color and up to  16 gray level B&W SSTV.  To 
achieve this you must use a terminal program which support the multi-level SSTV data 
format required by the MFJ-1278B. 
 
Each level of gray is represented by a tone produced by the MFJ-1278B modem.  The 19 
tones which can be produced by the MFJ-1278B FAX/SSTV modem (in Hz) are: 
 
1100, 1200, 1300, 1500, 1550, 1600, 1650, 1700, 1750, 1800, 1850, 1900, 1950, 2000, 
2050, 2100, 2150, 2200, and 2250. 
 
The tone being transmitted determines the shade of gray in the picture.  The sync tone of 
1500 Hz is automatically generated by the MFJ-1278B.  The other tones between 1550 Hz