Service Manual
Operating Principles
2.2.1.7
Circuit
This circuit uses the
receiver/driver
to change the signal level from the
signal level to the
signal level (O V or +5 V) or from the
signal level to the
signal level.
The
standard cell changes serial
data to parallel data.
Parallel Data
--------------
..... ----------””-
Serial
Data
Transmit
. . .
Receive
Figure 2-43.
Circuit
2.2.1.8 LocalTalk Circuit
The LocalTalk
is an optional
I/F board. It uses three
(ICI),
and
The
changes parallel data to serial data or serial data to parallel data.
It is controlled by
at the C135 MAIN board.
The
and the
which are signal level change
changes a TTL signal
level to a LocalTalk signal level (compatible with
signal level).
Cl
35 MAIN Board
CN7
Data Bus
Address
Bus
l/F Board (Option)
CN1
LocalTalk
DTR
.
RxD+/-
4
CTS
Figure 2-44. LocalTalk Circuit
2.2.1.9 Optional
This printer supports an EPSON Type-B optional interface, which is controlled by the INH and
signals from the
Rev.
A
2-29
