Epson LX-810

REV.-A
2.1.3 Circuit Overview
Figure 2-10 shows a block
f.
h,
,.
diagram of the TAMA board circuitry.
i PD78 10HG
(2 c)
B
EEPROM
(1 c)
r
PROM
32KB
(3C)
RAM
8KB/32KB
h
--7rmm ‘3”)’
ADDRESS BUS (UPPER BYTEI
XWl
DATA/ADDRESS BUS (LOWER BYTE)
~Q=
I
CONTROL PANEL
J
,LE
ADDRESS
A[)DRESS
CONTROL PANEL
LATCH
DECODER
LED DRIVE
+
24VDC +5VDC + 12vDC
I
I
GA E05A30 (36)
t
t
t,
‘Usir+km+=l
CG = character generator; GA = gate array.
Figure 2-10.
TAMA Board Circuit Block Diagram
The circuit consists mainly of the following ICS:
● ~PD7810HG CPU (2C)
The
~PD78 10HG executes the program in the PROM (3C) and controls all of the printer operations,
Upon receiving the RESET signal, the
CPIJ begins program execution from address OOOOH.
. . . . . .
<-.,’.,
● PROM (3C)
The PROM includes the control program (firmware) and character generators.
“ SRM 2064C (3D)
The
SRM 2064C SRAM is external melmory for the CPU. It is used as an input data buffer and line buffer
for expanding data, and as working area for the program.
2-8