Oki OKIOFFICE44 Service Manual page 285

CPU
from PC1
IC2
IOGA
from NCU
to Main power supply
(AC ON)
Board Descriptions
R44
CN4
TXDOPE 1 1
2 2
RXDOPE
OPECHK 5 5
13 13
PC1-N
OPERST 4 4
PSMODE 3 3
15 15
HUP-N
RIINT
14 14
MP/OFF 12 12
Figure A3.3.1 Block Diagram of OPE (operation unit)
OPE (04W) for OKIOFFICE 44
X'tal
CN1
IC1
MOS CPU
Internal ROM
Eight LEDs
LEDs
A - 43 OKIOFFICE 44 Serv. Man., P/N 59276801
KSCAN0
to
KSCAN7
Key switch
matrix
KSENS0
to
KSENS7
DB0
to
DB7
LCD unit
Control signals