Canon multipass c3000 Service Manual (en)

When the printer makes BUSY high, it cannot receive data.  The BUSY line goes high in
response to a -STROBE pulse.  This line remains high until the data are read.  BUSY is
also high under the following conditions:
• The receive buffer is full of data.
• The printer receives an -INIT signal.
• A printer error condition, such as out-of-paper, occurs.
P.E. (Paper End)
The printer sets P. E. high when it is out of paper or when a paper jam  occurs.  P. E.
remains high until the operator loads paper and presses the 
When the printer is ready, it sets the SELECT line high.  The SELECT line goes low
• An error condition, such as out-of-paper, occurs.
• The printer receives the Printer Deselect command.  It ignores all incoming data except
DC1, which returns the printer to a selected state.
If this signal is low when the printer is initializing, the printer automatically feeds the
paper one line when it receives a carriage return (CR) control code.  This signal is valid
only in Epson LQ mode.
-INIT from the system resets the printer to its initial power-on state.  The BUSY line goes
high, and any received data are printed.  When -INIT goes low, the printer resets itself to
the power-on default state.
The printer sets the ERROR line low if it detects an error, such as an out-of-paper
When this signal is high at initializing the printer, the DC1 and DC3 control codes are
valid; otherwise, they are invalid.  This signal is valid only in Epson LQ  mode.
Part 2: Printer