Table of Contents
Advertisement
>
o 5
Ф
-
a
x
Parallel Interfacing
64
A method of transferring data from a computer to a printer through a parallel interface based on the
Centronics Standard.
Specifications:
edata transfer speed: 1000 cps minimum
esynchronization: external STROBE pulse
@logic levels: TTL (Transistor-Transistor-Logic) levels -
ehandshaking: BUSY and ACK signals
econnector type: 57-30360 (AMPHENOL) or equivalent
ecable: use a shielded cable (6'5" /1.95 meters) or less in length.
When the printer is processing data, the BUSY signal is high. The printer will not accept new data from the
computer. After the processing is completed, the BUSY signal goes low. (The BUSY signal is also high
when the printer is OFF LINE). When the busy signal occurs, the ACK signal goes low indicating to the
computer that the data has been processed and the printer is ready to accept more data. This handshaking
routine occurs each time a character is sent to the printer.
Printer Status signals
18
1
осооооооооооооооооо
оооооооооооооооооо
36
19
Parallel Interface Connector (Printer side)
Signal | Return
pin
side ET
AUTO FEED XT
Pin Xem
(Parallel)
Advertisement
Table of Contents
