IBM 6400-i05, Setup Manual

Page: 255 / 370

PC Parallel Interface Signals
255
PC Parallel Interface Signals
Data Lines 1 through 8. Provides eight standard or inverted levels from the
host that specify character data, plot data, or a control code. Data Line 8
allows access to the extended ASCII character set. You may enable or
disable this line via the Data Bit 8 parameter on the Centronics submenu.
Data Strobe. Carries a low true, 100 ns minimum pulse from the host that
clocks data into the printer.
Paper Instruction (PI). Carries a CVFU signal from the host with the same
timing and polarity as the data line.
Acknowledge. A low true pulse from the printer indicating the character or
function code has been received and the printer is ready for the next data
transfer.
Online/Select. A high true level from the printer to indicate the printer is ready
for data transfer and the Start key on the operator panel has been activated.
When the printer is in Ready mode, it may accept data from the host.
Paper Empty (PE). A high true level from the printer to indicate the printer is
in a paper empty or paper jam fault.
Busy. A high true level from the printer to indicate the printer cannot receive
data.
DATA STROBE
Return
1
19
EXTERNAL 5 VOLTS 18
PAPER
INSTRUCTION
Return
15
33 N SELECT 36
Table 8. Printer PC Parallel Interface Connector Pin Assignments
Input Signals Output Signals Miscellaneous
Signal Pin Signal Pin Signal Pin