Citizen Systems CBM1000 Manuel D’Utilisation

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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:

8 bit parallel

Synchronizing method:

Controlled by nStrobe signal externally supplied

Handshaking:

Handled by nAck and Busy signals

Signal level:

All signals are TTL compatible

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.

1

2—9

10
11
12
13
14
16
15
17

18–25

nStrobe

Data0—7

nAck
Busy

PError

Select

nAutoFd

nlnit

nFault

nSelectln

GND

1

2—9

10
11
12
13
14
31
32
36

19—30
15—18
33—35

nStrobe

Data0—7

nAck
Busy

PError

Select

nAutoFd

nlnit

nFault

nSelectln

GND

N.C.
N.C.