Sharp MZ-3500 Keyboard controller signal description, Pin, XTAL1 XTAL2 Reset INT, ALE DBO DB7 GND

MZ3500

10-5. keyboard controller signal description

PIN	Porality	IN/OUT
	signal
No
	name
1	TO	IN
2	XTAL1	IN
3	XTAL2	IN
4	RESET	IN
5	SS	IN
6	INT	IN
7	EA	IN
8	RD	-
9	PSEN	-
10	WR	-
11	ALE	-
12	DBO	IN
19	DB7
20	GND	IN
21	P20	OUT
22	P21	OUT
23	P22	IN
24	P23
25	PROG	-
26	VDO	IN
27	P10	OUT

30P13

31P14-

32P15

OUT

34P17

35P24IN

36P25

IN

38P27

39T1IN

40VccIN

Function

Output data signal from the sub CPU (D(O)

Internal clock oscillator crystal input

Internal clock oscillator crystal input

Processor initialize

+ 5V

Strove of D(C) that also is used for interrupt to the keyboard side (ST(O)

GND

NC

NC

NC

NC

RETURN signal from the keyboard is input when a key is pushed during key search

0V supply

Output data signal from key (D(K))

Strobe of D(K) which also is used for interrupt to the CPU side (ST(K))

Not used

NC

+ 5V

Strobe to the keyboard unit by which a hexadecimal code is sent out for generation shift pulses to terminals X O X 1 5 o f t h e 4 5 1 5 decorder during key search

NC

Pins used to activate the keytop embeded LED #32 pin Alphabets and symbols (LOCK) #33 and #34 are not used

Not used

Keyboard type identifier pin Keyboard type is identified by mears of KSO, KS1, KS2 of KUC1 an KUS2. whether it is GND or NC

Acknowledge input from the CPU (ACK(O) Sent only when the CPU receives a correct data

+ 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 I/F. 128KB RAM. 16KB ROM (for ROM based machine) checks

[Procedure]

LED (fof id«niific«Tion of GO/NO GO)

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

mdicsted (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 activat ed and flickered