Sharp MZ-800 Service Manual page 41

MZ-800
3-6. Colour plotter printer control LSI
Pin assignment
Symbol
Name In/out
Function
Vss
Ground
Connected to OY.
Vcc
Main power
Connected to 5Y.
Voo
Power
Connected to 5Y.
PROG
Program
I
Out Not used.
Plo ~P17 Port I
Used as printer control signals.
P2
0
~ P27
I
Port 2
Used for data input port from CPU.
Do - D7
1 Data bus
Used for stepper motor control signals.
I
To
Test pin 0 In Input from pen change switch.
Tl
1
Test pin 1
In
I
Input from paper feed switch.
INT
i
Interrupt input In Data transfer strobe MZ- 700 ... MZ 1 PO 1.
I
RD
I
i
Read signal In Not used.
-
I Write signal I
Out
Not used.
WR
i
I
RESET
!
Reset
In Used to initialize the processor.
ALE
1
Address latch enable Out
I
Not used.
I
I
I
PSEN
I
Program store enable
Out
I Not used.
SS
I
Single step In Not used.
EA
External access In
Active when EA = OY.
Pins used to attach the crystal oscillatQr or RC network to
Xl,
Xl
Crystal inputs
In
generate internal clock. However, external clock signal may be
inputted through these pins.
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