Appendix 4. Parallel Interface - Citizen CBM-1000 User Manual

APPENDIX 4. PARALLEL INTERFACE

1 Bidirectional Parallel Interface (IEEE1284)
1.1 Compatibility Mode (Host → Printer communication: Centronics compliant)
(1) General description
This printer provides Compatibility Mode, which specifies the Centronics
interface conventionally used for a wide variety of applications.
(2) Specifications
Data transfer method:
Synchronizing method:
Handshaking:
Signal level:
1.2 Reverse Mode (Printer → Host communication)
Data transfer from the printer to the host computer is conducted in Nibble or Byte
Mode.
(1) Outline
The reverse mode has been devised to handle data transfer from an
asynchronous printer controlled by a host computer.
In Nibble Mode, data is transferred, 4 bits (a nibble) at a time, using traditional
control lines. In Byte Mode, data is transferred by making 8 bit data lines
bidirectional. Note that either mode cannot work simultaneously with
Compatibility Mode, thus resulting in half-duplex transmission.
2. Connector Pin Assignments
Host side
D-Sub 25 pin (Male)
Pin No.
1
2—9
10
11
12
13
14
16
15
17
18–25
8 bit parallel
Controlled by nStrobe signal externally supplied
Handled by nAck and Busy signals
All signals are TTL compatible
Signal name
nStrobe
Data0—7
nAck
Busy
PError
Select
nAutoFd
nlnit
nFault
nSelectln
GND
— iii —
Printer side
IEEE1284-B (Receptacle)
Pin No. Signal name
1 nStrobe
2—9 Data0—7
10 nAck
11 Busy
12 PError
13 Select
14 nAutoFd
31 nlnit
32 nFault
36 nSelectln
19—30 GND
15—18 N.C.
33—35 N.C.