Self check functions, Test regarding the main cpu, M/3500 – Sharp MZ-3500 User Manual
Page 87
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M/3500
10-5. keyboard controller signal description
PIN
No
Porality
signal
name
IN/OUT
Function
1
TO
IN
Output data signal from the sub CPU (D<0)
2
XT A LI
IN
Internal clock oscillator crystal input
3
XTAL2
IN
Internal clock oscillator crystal input
4
RESET
IN
Processor initiatire
5
SS
IN
+ 5V
6
INT
IN
Strove of D(C) that also is used for interrupt to the keyboard side (ST(0)
7
EA
IN
GND
8
RD
-
NC
9
PSEN
-
NC
10
WR
-
NC
11
ALE
-
NC
12
DBO
IN
RETURN signal from the keyboard is input when a key is pushed during key search
19
DB7
20
GND
IN
OV supply
21
P20
OUT
Output data signal from key (D(K))
22
P21
OUT
Strobe of D{K) which also is used for interrupt to the CPU side (ST(K))
23
24
P22
P23
fN
Not used
25
PROG
-
NC
26
V
do
IN
+
5V
27
P10
OUT
Strobe to the keyboard unit by which a hexadecimal code is sent out for generation shift pulses
30
P13
to terminals XO X15 of the 4515 decorder during key search
31
P14
-
NC
32
PI 5
Pins used to activate the keytop embeded LED
OUT
#32 pm Alphabets and symbols (LOCK)
34
P17
#33
and
#34 are not used
35
P24
IN
Not used
36
P25
IN
Keyboard type identifier pin Keyboard type is identified by mears of KSO, KS1, KS2 of KUCI
38
P27
an KUS2. whether it is GND or NC
39
T1
IN
Acknowledge input from the CPU (ACK(O) Sent only when the CPU receives a correct data
40
Vcc
IN
+ 5V supply
11. SELF CHECK FUNCTIONS
The -3500 performs self-check test during initial program
loading of the ROM. 11-1.
Test regarding the main CPU
1) MFD l/F, 128KB RAM, 16KB ROM
(for
ROM based
machine) checks
[Procedure]
1. Turn on all dip switches of the 4 bit switch (located in
the middle of the front side of the board) and turn on
all dip switches of the
2
bit unit on the front side of the
board.
2. Insert a floppy disk into drive unit No 2 (the third drive
unit)
3. Turn the power on
4.
The LED flickers for a moment then the test program
starts During execution of the test program, the LED
stays
unlit
About
four
seconds
later
the
result
is
indicsted
(DISPLAY)
(1) LED comes activated after normal ending of the test
(2) LED flickers after abnormal ending of the test
The kind of error can be known by how the LED is activât
ed and flickered
- 94
LED (tor tdenitfication of GO/NO GO)