Epson LQ-860 Technical Manual page 75

REV.-A
2.3 CONTROL CIRCUIT BOARD (JUNMM Board)
Figure 2-23 shows a block diagram of the JUNMM board. The printer employs 8-bit one-chip CPU
,uPD781O, to control all of the printer operaticm. The printer is driven with a 9.83 MHz clock. Moreover,
various gate array ICS and hybrid ICS are employed to lighten load to the CPU, so that the CPU circuit can
be simplified and data can be processed at high speed.
RESET
,
L
I d
- - -
- -
I
MODULE
L - - - - - _ .J ~
I I I *
C.G.' (3A)
ST-RAM (7A)
S-BIT PAFiALLEL l/F
PORT EX13WJSION
G/A (llB)
L
HOST #81D0
l/F BOARD
Figure 2-23. JUNMM Board Block Diagram
DRIVER
CR MOTOR
DRIVER
PRINTHEAD
DRIVER
PF MOTOR
DRIvER
2-28
I
PRINTER
MECHANISM
CR HP SENSOR
CR MOTOR
(1A)
PG
SENSOR
PRINTHEAD
THERMISTOR
PRINTHEAD
I
PF MOTOR