Epson PX-8 - Page 34

Q23
Backup line
R26
4.1K 016
Q20
11
20K 20K
.- __ ,Q,,:6 r-~.-_ .... Logic circuit
+ C6 power (+5V)
supply
420
14
Q3
__ --~ r--~----'
-
Auxiliary
-
battery
R43
~
GNO
471<
10
9
'----0 VB(+)
(Main battery voltage)
Note:
----:------::--::--c-
P70: POWER ON signal
High
turns power off, and
Low turns power on.
8
Fig. 2-6
P42: Main --+ auxiliary battery switching signal
High selects auxiliary battery, and
Low select main battery.
2-10
To RAM, etc.
POWERSW
C64
VOO G
POO ( INTO)
7508
(2E)
~------ ....... ....--t P42
5
\r'T- ..... -..., .)t--+-----i P 70
REV.-A