Sharp PC-1600 Service Manual page 32

Pin
Symbol ln/Out
No.
38 KC3
39 KC2
40 KCl
KCO
41
42 R33
43 R32
44 R31
45 R30
46 R23
R22
47
48 R21
49 R20
VRL
50
51 SIN
52 VOO
R13
53
54 R12
Rll
55
Rl0
56
57 R03
58 R02
ROl
59
ROO
60
Q3
61
62
Q2
Ql
63
64 QO
Active State
level
at ACL
In
Not used.
Used for checking the CE-1600P power supply level. VPP supplied from
In
the CE· 1 600P via the system bus is A/O converted. If it is below the given
level, the peripheral is assumed to have a weak battery condition.
In Used for checking the PC· 1 600 main power supply level. The level of the
main power supply is A/O converted and checked. If it is below the given
level, a weak battery condition is assumed.
Receives the signal input from the analog input connector.
In
(1)
(2)
Out In MSB
Out In
Out In
Out In
In
Out
In
Out
Out In
In
Out LSB
NC
In NC
High power supply voltage level (VGG).
In In
MSB
In In
In
In
In In
In In
In In
In In
In In LSB
In Low In Hardware sensed weak battery detection signal.
A high on this line causesthe CPU to force the system to go down. The only
means to turn the svstern on after recovery of power supply is the depression
of the BREAK/ON key or ALL RESET switch. The time in the real-time
timer would not be revised.
In Not used. Pulled down.
In
In Low In Opposite polarity as CI of the R5-232C interface. It is possible with CI to
turn on the system when the system is off (when this line is at a low level).
In Low In 1fthis signal is at a low level when the system-off command is received from
the Z-80, the system is turned off.
-29-
Function
For the analog input, A/O conversion is done.
For the external keyboard input, its logic level is interrogated.
Return data to the Z-80.
Command from the Z-80.
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PC-1600