DMP-133  (260-2815)             Buffer                 Faxback Doc. # 4285

The printer's ability to temporarily store data is one of its main advantages 
over a typewriter. Codes sent to a printer are not printed immediately; they 
are stored in a separate section of memory in the printer called the buffer. 
This allows for faster printing operations in most cases, while the computer 
continues to send characters. The printer does not have to wait for the 
current character to print before receiving the next one. When the buffer 
fills or certain codes are received (LF or CR), the buffer is emptied and all 
data is printed on the paper.

* The buffer allocates a fixed number of dots depending on the character 
  width selected. The buffer empties when the data stored equals that 
  number. In Tandy mode the buffer can hold the 100 characters that are 
  available across one line of print.

* When the printer receives the start graphics mode code followed by stand-
  ard characters, the buffer prints. Dot graphics printing continues from 
  the current character position.

* In graphics mode, the buffer prints when the printer receives the end  
  graphics printer control code and returns to a normal character printing  
  condition.

* Repeat data can cause a buffer full or overflow condition. The overflow  
  characters or data are wrapped around and printed at the beginning of the  
  next line.

* In DP and WP modes, if you select a character set of different dot density,  
  the data in the buffer prints. Printing continues from the current posit-
  ion.

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

* The form feed code (FF) automatically activates printing.

* In WP and DP modes the backspace command activates printing. Printing  
  continues in the current line at the dot address specified by the command.


(smm 07/26/93)