HP 9020 CE Handbook page 121

9-18
9020
Diagrams
lOP BUS
lOP BUS
C
INTERFACE
(50-PIN)
t
PC
(50-PIN)
POWER/MISCELLANEOUS
CONTROL
tQPBUS
J4
(50-PIN)
POWER
J2
(SO-PIN)
INTERFACE
BUFFERS
~
OPTIONAL INPUT DEVICE
1
TB
(14-PIN)
t
KEYBOARD AND
KBDC
MISCELLANEOUS
INPUT DEVICE
(20-PIN)
KEY SWITCH
STATUS AND CONTROL
SCANNING
BOARD
DATA
1
R1,3,15
j
R10
1
R11
1
R9,12
RTC,NVM
POWER-UP
BEEPER
1 -
POWER-DOWN
LOGIC AND ENABLE
SENSE CIRCUITRY
KEYBOARD ELECTRONICS BOARD
Keyboard Block Diagram
CONTROL
DISPLAY ALPHA
J1
(36-PIN)
I
DISPLAY GRAPHICS
J3
(36-PIN)
Display Interface Module (DIM) (9020B/C Only)