Epson ActionLaser 1600, Service Manual

Page: 90 / 181

Principles of Operation
Parallel Interface Circuit
Figure 2-41 shows a block diagram of the parallel interface circuit block. Data
sent from the host computer is latched within the E05A93 by the STROBE signal.
The E05A93 outputs the BUSY signal automatically to stop the host computer
from sending additional data. The CPU resets the BUSY signal after reading the
data from the E05A93, so that the printer is ready to receive more data from the
host computer.
F i g u r e 2 - 4 1 . P a r a l l e l I n t e r f a c e C i r c u i t
RS-232C Circuit
This circuit uses the RS-232C receiver/driver IC ADM232 (IC28) to change the
signal level from the RS-232C signal level (--12 VDC or +12 VDC) to the TTL
signal level (0 V or +5 V) or from the TTL signal level to the RS-232C signal level
This IC co5 VDC to +12 VDC and –12 VDC. The E05A93 standard cell
changes serial (RS-232C) data to parallel data.
Figure 2-42. RS-232C Circuit
2-32
EPSON ActionLaser 1600 Service Manual