DMP 106  (260-2802)             Buffer                Faxback Doc. # 4402

The DMP-106's ability to temporarily store data is one of its main
advantages over a typewriter. Codes sent to a typewriter (i.e., 
keys pressed) are transferred immediately to the paper. Codes sent 
to a printer are not printed immediately; they are stored in a
separate section of memory in the Printer called the buffer. When
the buffer fills, or certain codes are received (i.e., LF or CR),
the buffer is emptied and all data is then printed on the paper. 
What happens after the buffer data is printed depends on the 
circumstances. In some cases, printing continues on the same line;
in others, the Print Head is moved to a different position relative 
to the paper. In the CP Mode, commands for changing print fonts, Line
 Feed, etc., can be stored in the buffer to take effect when the data 
is dumped to paper.

Understanding how the buffer works is important for those who wish to 
gain full control of the DMP-106.

HINTS AND TIPS ON THE DMP 106 BUFFER

FOR CP AND GRAPHICS MODE

* The buffer allocates a fixed number of dots, depending on the character
  width selected. The buffer is emptied when the data stored equals that  
  number.

  If different character widths have been used on the same line, the last
  character added may exceed the dot count. The buffer is printed without
  this last character.

* The Carriage Return (CR=13decimal) code automatically activates printing
  (assuming at least one character code is already in the buffer).

* The Line Feed (LF=10) codes automatically activates printing, and the
  Print Head is positioned at the start of the next print line.

* If the computer delays more than a second before sending the next print
  code, the buffer is printed. Printing continues from the current 
  position.

* The Print Head Positioning sequence (27 16 n1 n2) prints the buffer.
  Printing continues in the current line at the dot address specified by 
  the (27 16) command.

* When the buffer is full, the buffer is printed. Printing continues from
  the current position.

CP MODE ONLY

* If a character set of different dot density is selected, the data in the
  buffer is printed. Codes for changing character sets are: (27 19),
  (27 20), and (27 23). Printing continues in the current line with the
  new character style after adding some dot space.

* Dot graphics printing continues from the current character position.

* When a start Bold or end Bold is received, the buffer is printed. Bold
  printing continues from the current character position.

* Since the buffer capacity is small. if you frequently use the Underline
  and/or Elongated features, the buffer may be printed before the contents
  exceed the capacity for one line. Printing will continue from the current
  line.

* If CR = CR feature has been selected, reception of the Carriage Return
  (CR=13) codes causes the buffer contents to be printed followed by a
  Carriage Return, and the next full buffer will overprint on the current
  line. If CR=CR+LF(NL) has been selected, it will cause the buffer 
  contents to be printed followed by a New Line (CR AND LF). Printing
  will resume at the start of the next print line.

GRAPHICS MODE ONLY

* When the End Graphics Mode command is received, the buffer is printed.
  The Printer returns to the CP Mode and printing continues in the same 
  line from the current print position.

NOTE: Repeat data can cause a buffer full or overflow condition, as well as
single characters.

(abo-07/26/93)

Privacy Policy