Oki OKIOFFICE84 Maintenance Manual page 291

IC2
IOGA4
from PC1
IC2
IOGA4
RIINT
from NCU
to Main power supply
(AC ON)
Figure A3.2.1 Block Diagram of OPE (operation unit)
R51
CN4
TXDOPE 1 1
2 2
RXDOPE
OPECHK 5 5
13 13
PC1-N
OPERST 4 4
PSMODE 3 3
HUP-N 15 15
14 14
MP/OFF 12 12
A3 - 21
OPE (04W)
X'tal
CN1
IC1
MOS CPU
Internal ROM
Eight LEDs
LEDs
OPE (04W)
KSCAN0
to
KSCAN7
Key switch
matrix
KSENS0
to
KSENS7
DB0
to
DB7
LCD unit
Control signals
40672201TH Rev. 4