Sharp Mz-700 series User manual

MZ-700

SERVICE MANUAL

-r'

.............................................................

..

SHARP

INDEX

CODE: OOZMZ700SM

I/

E

PERSONAL COMPUTER

MODEL

MZ-700

MZ-1TOl

MZ-1POl

(FOR THE MZ-lPOI MECHANICAL SECTION

REFER

TO

THE DPG2306 SERVICE MANUAL)

1.

SPECIFICATIONS.

. . . . . . . . . . . . . . . .

..

. . . . .

..

. . . . .

..

. .

..

. .

..

1

2.

NAMES OF

FUNCTIONAL

COMPONENTS. . . . . . . . . . . . . . . . . . .

..

2

3.

SYSTEM BLOCK

DIAGRAM

..............................

_

..

3

4. SYSTEM

DESCRIPTION.

. . . . . . . . . . . . •. . . . . . . . . . . . .

•.

. . . . .

..

4

5.

DATA

RECORDER

....................................

....

15

6.

COLOUR ENCODER

.......

.

........

. .

..

......

.

............

19

7.

MICRO COLOUR GRAPHIC PRINTER

.........................

20

8.

POWER

SUPPLy

...................

.

.............

•

........

24

9.

IC

SIGNAL

POSITION

.......................•...........

. . 27

10.

CIRCUIT

DIAGRAM

& PARTS

LAyOUT

...•.

..

...

..

....

..

....

29

11.

PARTS GUIDE & LIST

SHARP

CORPORATION

~\~Z~

700

1.

SPECIFICATION

1-1.

MZ-700

CPU

Oock(ct»

Memory

Video

output

Screen structure

Color designation

Music function

Timepiece

function

Keyboard

Editing functions

Power

requirements

Temperature

Humidity

Weight

Physical

dimensions

Sharp LH0080A (Z-80A)

3.5MHz

4KB ROM (monitor)

4KB ROM (character generator)

64KB RAM (program area)

4KB RAM (VIDEO)

System: PAL

Type: RGB composite video (con-

vertible

to

B/W)

RCB + Syncronization

(non

composite)

RF

(UHF

36

± 3ch, conver-

tible

to

B/W)

40

character x 25 lines

(1000

chara-

cters)

8 x 8

dot

matrix

(per

character)

Character: 8 colours

(per

character)

Background: 8 colours (per character)

Internally provided (audio

output,

55OmVmax.)

Internally provided

(24

hours clock,

without data retention)

ASCII compatible

69

keys

Defmable keys,cursorcontrolkeys, etc.

Screen editor (cursor control, home,

clear, insert, delete)

220/240V ± 10V, SO/60Hz

Operating temperature: 0

to

35°C

Storage temperature:

-20

to

70°C

Operating humidity: 85%RH or

below

3.6Kg

(body

only)

440

(W) x 305 (D) x

86

(H)

1-2. CPU board specification

CPU

LH0080A (Z80A) . . . . . . . .

..

I

PlO 8255

..................

I

CTC 8253

...................

I

Memory controller M60719

................

I

(CRTC)

ROM

RAM

I/O bus

4KB

monitor

ROM . . . . . . . . .

..

I

4KB character generator

ROM

...

I

64K bits DRAM . . . . . . . . . . .

..

8

2KB SRAM

................

2

Expansion I/O bus

...........

I

Printer I/O bus . . . . . . . . . . . .

..

2

(Only one can be used, selectable

by

switching)

External cassette read/write terminals

1-3. Micro-colour graphics printer specification (option)

Printing method Ball point pen recording, four colours

rotary selection type.

Kind

of

colours I =black, 2 =blue, 3 =green, 4= red

Printingspeed

10

characters/sec, average (Printing the

smallest characters.)

Printing capacity

80

digits,

40

digits, 26 digits, soft-

ware designated

Character set 115 characters (ASCII characters and

others)

Resolution 0.2mm

1-4. Cassette recorder specification (option)

Type IEC compatible cassette mechanism

Record/playback

method

Dual tracks, single channel, monopho-

nic

Rated speed 4.8cm/±3.5%

Operation control

method Piano key

method

Control

buttons

PLAY,

FF,

REW, STOP/EJECT, REC,

COUNTER RESET

Data transfer .

system

Baud rate

Tape

used

Sharp,

PWM

method

1200bps(nominal)

Philips standard tape,

(not

C120)

1-5.

Powersupply specification

(Including colour graphics printer and cassette tape

power source)

Input:

220/24OV ± 10V, 60/50Hz, 20W

Output:

5V

2.

NAME

OF

FUNCTIONAL

COMPONENT

MZ-700 Front view

Main

kev

board

-----'

MZ-700

Aeer

view

Channel switch

RF

terminal

BrN-Colour

switch

Composi!

terminal

Dat8 recorder

!c3S$IIttll)

AGe

terminal

CantUI!

re<:order

jKk

EKt.

output

terminal

Joy

nick

ulfminal

1

plOHtr

printer

Ext.

printer

terminal

MZ-700

plolter

prioter

recorder (cassette)

INS.

DEL

key

":::d'---,----CUrSOI

control

keV$

.

socket

Reset switch

Volume

Adiust

F,.me

ground

termmal

~"q-700

3. SYSTEM BLOCK DIAGRAM

( CRT

F.G

A.C.

sw

100V

I~

-""

t t

~PO~UP'

!II

0-

5V

MEMORY CONTRa.

Fi

p w R.G.B. I I

PLY CIRCUIT

llER

(CRTC)

VIDEO

RAM

a::

Cl

-..,

I I

,.--

:Ja::

00

RF I I

~

~~

...JU

oz

-uw

_J

I

eJ

Reset

RESET 1

~

I

CHAR

a::

VIDEO

CIRCUITJ I GEN

....

...J

sw

c(

MAIN

~

MEMORY

64KB

DRAM

MONITOR

ROM

Z80A

i-

III

IT

CPU

A

,......

\ ADDRESS

BUS

\

I

n I

n=

-y

en

:J

A "

III

~dJA

\

Q.

I -

"

ft

H

rn.

t\.0

-t "

a:

..

X

(ONTROl

BUS

I--

. w

...-

>

I--

...

~I

?8m

ER!-

f--

I--

'--

r

f--

~

t

!.

8253 (CTC)

r-

8255 (PlO)

EMPO

CO

C1

C2

CONTROLLER

t,;J~

">

0(

CASSET·

Audio TEMPO. +

f..--

KEY I

TECONT·

11

JOY STICK1

amp. CURSOR

OSC.

BOARD ROLLER CIRCUIT

I

~

I--

t

PRINTER

CONTROL

LER

~

r "\

PRINTER BUS J

CASSETTE JOY STICK

TERMINAL

~

U U I

CASSETTE

3

4.

SYSTEM

DESCRIPTION

4-1.

Memory map

a) At power

on

$0000

$1000

$1200

$0000

$0800

$EOoo

$FOoo

MONITOR

(ROM)

MONITOR WORK

SYSTEM

and

TEXT

AREA

(DRAM)

V·RAM<CHARACTER>

(SRAMI

V·RAM<COLORDATA>

(SRAMI

KEY

and

TIMER

PORT

FLOPPY CONTROLLER

Enable

$0000

$1000

$0000

SYSTEM

(DRAM)

and

TEXT

AREA

SYSTEM

and

TEXT

AREA

(DRAM)

Disable

• Shown above

is

the memory map at the time

of

power

on.

VRAM

contents from$DOOO to $DFFF differ from

the MZ·80K.

• The monitor (ROM) has the same entry point

as

that

of

the MZ·80K.

b) Bootstrap (loading

of

system program)

$0000 $0000

MONITOR

Ir--

(ROfv\)

1'-

SYSTEM

$1000 LOAD

SYSTEM

$7EOD

Boot PROGRAM

~

'11

$0000

V·RAM

$EOoo

KEY and

TIMER

PORT

SYSTEM

Eneble Disable

• With the input

of

the LOAD command

of

the monitor,

the

BASIC

loading program

is

transferred

to

the system

area composed

of

the

RAM

and starts

to

bootstrap.

(Only the cassette tape

is

subject

to

bootstrapping in

this case).

4

• Boot command: L

• With the entry

of

the boot command

L,

only the tape

loading program

is

transferred

to

the system area and the

system program

is

loaded

to

the system area designated

in the DRAM.

NOTE: The boot program shown in the figure

is

the

program loaded from the tape and

is

not the

program from the monitor (ROM).

c) System initiation

$0000

$1000

MONITOR

(ROM)

.$0000

,-------,

V·RAM

$Eooo I--KE-Y-ond-TI-M-ER-P-OR-T-l

:$Fooo

1--------1

Disable

$0000

,-----,

SYSTEM

$1000 ----------------------

$0000

---------------------------

Enable

• The above memory map is valid upon completion

of

system program loading.

• The system program

is

programmed

to

switch the

memory depending upon what

is

accessed,

VRAM,

keyboard, or timer.

d) At

the

time

of

manual reset

$0000

$1000

MONITOR

(ROM) $0000 I SYSTEM

$1000

~-----~

SYSTEM

$0000

,-------,

V·RAM

V-RAM

$EOoo

KEY

and

TIMER

PORT

SYSTEM

$FOoo

Enable Disable

~1Z

-7CO

At the time

of

manual reset (with I

CTRL

I in depression)

$0000

SYSTEM

~

MONITOR

-

(ROM)

$1000

SYSTEM

$0000

V-RAM

$EOoo

KEY

and

TIMER

PORT

SYSTEM

$FOOO

~

MEMORYCHANGE

'--

Disable Enable

•

When

the IC T R L Ikey

is

in depression, address $0000

through $OFFF and

$DOOO

through $FFFF become

the

RAM

area.

• With input

of

the command ":If' when the monitor

(ROM)

is

active, it

is

switched

to

the

RAM.

e) Floppy bootstrap

$0000

....--------,

MONITOR

(ROM)

$1000

f----------I

SYSTEM

iI-

Iv

$DOOO~----~

V-RAM

$EOoo

i-

K

-E-y -an-dT-IM-E-R-PO-R-l

-I

$FOoo

f----------I

FLOPPYCONTRO~L-

Enable

$0000 I SYSTEM

$1000

~----~

LOAD

$0000

,------,

SYSTEM

Disable

• Because the floppy control area

is

mapped to

$FOOO

for

compatibility with the MZ-80K series, boot begins

from the adress

$FOOO.

•

Map

configuration after boot will

be

considered sepa-

rately.

4-2. Memory controller (CRT

C)

Both the momory controller and the CRT controller

are

contained in a

single

chip custom

LSI

(M60719), it

has the following functions:

5

a.

8 x 8 dot characters are displayed on the CRT screen

of

40

characters (horizontal) x 25 lines (vertical). Displayed

character font

is

dependent on the

4KB

character

generator (ROM).

b.

Manages

the monitor

ROM,

DRAM, video

RAM,

and

peripherals (keyboard, timer, ETC.) mapped to the

memory.

c.

Generates clock to the Z-80A microprocessor.

d.

Selects the printer I/O port.

1) CRT controller

There are major variations

of

colour television systems

as

described below.

1.

NTSC

system (Japan, U.S.A., etc.)

2. PAL system (U.K., Germany, etc.)

3.

SECAM

system (French, etc.)

Because

of

the different specification requirements above,

the

MZ-

700 may not be suitable for overseas operation.

PALsignal specification

Signal name Signal frequency

NTPL

"L"

LPHI 17.734475

MHz

CLKN 8.8672375

MHz

COLR 4.43361875

MHz

WAD

1.108404688

MHz

PHIO 3.546875

MHz

HBLN

15.6113 kHz

VBLN 50.0363

Hz

CRT

controller

system

block

diagram

H

NTPL

CPU

WA

CPU

Blanking period

COLR

HSY

SYN

VBLK

HBLK

CLK

LOAD

TV

Oata written in

the

VAAM

from

the

CPU

is

input

to

01-08

via

the

bidirectional

buffer

5245.

To display characters on the CRT screen, the

CPU

writes

the character data (display code) to the

2KB

VRAM-l

along with the control signal

WR

and the color data

of

that character

to

the

2KB

VRAM-

2.

In other words,

as

the address

($DOOO

,..,

$D7FF)

is

output. The character

data

is

supplied to the VRAM-l input (01-08)

via

the bidirectional buffer LS245, and the data will then

be written when

WE

is

low. The color data

is

also sent to

01-08

of

the

VRAM-2

to be written when

WE

is

low.

To read the contents

of

a

VRAM

character, the

CPU

sends

out

the relevant address. When

RD

is forced low, the

data

is

then read

via

the bidirectional buffer LS245.

However, the address range

$0000

through $DFFF must

be addressed in order to access

all

the

VRAM.

This address

change

is

carried

out

inside the custom

LSI

with the OUT

command described later.

Accessing

of

the

VRAM

is carried

out

within the blinking

period (BLNK = "H").

If

BLNK =

"L",

then

WAIT

is

applied to the

CPU

(WA

= "L").

The blanking period discussed here

is

the period that

BLNK

is

in high level.

High

period

of

the BLNK signal

is

so

designed that it

is

shorter than the low period

of

HBLK (horizontal blanking

period).

HBLK

versus

BLNK

HBLK~

,

BLNK--,L.

____________

~--~I

!

~

I:

L"I----

, 1

I'

-:

l--

2.165081-1S

Display period

The data written in the

VRAM

is

sent

to

the

CG

ROM,

character

by

character based on the display address counter

located inside the custom LSI, to become the

CG

address

data (VRAM-l data). Also, the data

of

VRAM-2

is

sent

to the LS174, at this point. The

CG

receives the VRAM-l

data and low order address bits (Q-Q3).

It

is

then sent to

the shift register LS165 after being converted into the

8-bit parallel character row data. The shift register converts

this signal into serial data and it

is

added to the color

matrix circuit along with the data from the LS174 to

become the R.G.B. CVIDEO signal.

Po

-PlO: These are

VRAM

addresses

that

represent the

character position

on

the CRT screen.

Ql -Q3: These represent the rows

of

the 8 x 8 dot

character. Row number

is

increased with

HBLK,

and it repeats 0 through 7

as

shown

below. These signals are also generated inside

the custom

LS!.

as

a2 a1

1st row 0 0 0

2nd

row 0 0 1

3rd row 0 0

4th

row 0 1 1

5th

row 1 0 0

6th

row 1 0 1

7th

row

1 1 0

8th

row 1 1 1

6

LOAD:

CLK:

The signal that determines the function (shift

out

or data set)

of

the shift register LS165.

High state

of

this

signal

acts

as

shift and low

state

of

this signal acts

as

data set.

Shift register clock. Data shifts at the rising

edge

of

CLK

when the

LOAD

signal

is

high.

•

HBLK

versus

HSY

!------Jr---

I 1

36.0881-1S

1 1 '

1-1

-----:...----;I-!'j

9.02201-1S

I I '

1

64.05603/015

1

I·

I

1J

W.

-l

:--

4.567375j.1S

• VBLK versus

SYN

VBLK

____

~

__

~r---

: 12.8112ms

:;

I

r-I--------·~I

r--2;8825mms

1

~_~1~9=.98==5m~s~

__

~_~.:.

u

, 1

1 1

--,

r--

0.19216ms

Custom

LSI

internal CRT controUer block diagram and

description

• Ql -

Q3

are created by dividing

HBLK

by half.

• Internal signal

CSDD

is

used to make the choice

of

VRAM

addressing, which

is

carried out by address

muitiplexing through the internal display address, or

comes direct from the

CPU.

A through K are the display

addresses.

• The

LPHI

signal (l7.7MHz)

is

divided and ANDed to

derive the horizontal synchronization signal

(NTSC

or PAL)

to

make the choise

of

either

NTSC

or PAL

horizontal synchronization signal, output by means

ofNTPL.

\

,'1Z

-700

2) Memory controller

In the

MZ·

700, it needs

to

segregate the memory in order

to acheive the above mentioned memory mapping. The

memory controller

is

therefore used

to

perform address

management

of

peripherals assigned

to

the memory such

as

DRAM, monitor

ROM,

video

RAM,

and keyboard. The

bank select method

is

used to switch memory. Memory

selection

is

acheived using the OUT command.

I/O

$0000

$DOOOO

~

l INHl INH2 INH3

port $OFFF

$FFFF

$EO

D·RAM -L --

$El -

D-RAM

-L -

$E2 MONITOR H

ROM

---

$E3

-V·RAM,8255 -H -

8253

$E4 MONITOR V·RAM,8255 H H H

ROM

8253

$E5

-Prohibited - - L

Returns

to

the

$E6 -state before --H

prohibitied.

INHl -

INH3

are custom

LSI

internal signals which cause

the memory map to change.

INH1

INH2

INH3

INH1

INH2

INH3

H L H H

H H L H

H H H L

I--D-_R:_:_M---I

1--:-.:-:-:---1

I---D-_:_OA_MM----j

I

:::

I

V·RAM V·RAM

D-RAM

L

H

D·RAM

D-RAM

D·RAM

H

L

ROM

D-RAM

L

H

L

D-RAM

L

D-RAM

D·RAM

NOTE: The command with which the memory selection

is

to

be

done should not

be

written in the memory

block to be selected.

7

• Custom LSI internal memory controller block diagram

and description

When the above mentioned OUT command

is

executed,

address

Ao

,..,

A2

is stored in

"FF"

to

create INHl

,..,

INH3,

then

ROM,

VRAM, and

DRAM

may be accessed

against CPU addressing

on

the basis

of

those INH signals.

•

RA~

becomes active when the DRAM

is

accessed.

•

CSO

becomes active when the monitor

ROM

is accessed.

•

CSE

becomes active when the memory mapped I/O

(8255,8253)

is accessed.

• CSDN (internal signal) becomes active when the VRAM

is

accessed.

If

in the blnk period, CSDD becomes active.

So

that, the address from the CPU

is

sent

of

Po

,..,

PlO.

•

If

the display period is

on

when accessing the

ROM

or

VRAM, WATN becomes active.

•

line

address and row address switching signal (LS157

input) when accessing the

RAM

is derived from PHI,

WRN,

MRQN, and RDN.

As

WR

rises before the falling

edge

of

CAS

during the write cycle,

it

becomes an early

cycle.

IV?

7ce

4-4. Memory controller (CRTC) circuit description

The memory controller and

the

CRTC are contained in

the

single chip custom LSI (M60719).

Memory controller signal description

&

Pin No. Signal name IN/OUT

Function

Circuit diagram

signal name

1

AO

CPU address Bus AO

l l IN l

16 A15 A15

17 LPH1 IN Clock (17.7MHz)

<I>

18

PHI

IN CPU clock (3.55MHz)

cp

19 CSEN OUT 8255, 8253, joystick enable

CSE

10 CL IN GND CL

21

GATE IN GND GATE

22

CSON OUT Monitor ROM enable

CSO

23

VCC

-Power supply 5V

24

RASN OUT D-RAM row address select RAS

25 RFSN IN CPU refresh RFSH

26 PHIO OUT CPU clock create signal (3.55MHz)

cpo

27 MRQN IN CPU memory request MREQ

28 10RN IN CPU I/O request IORQ

29

RDN IN CPU read RD

20

WRN IN CPU write

WR

31 RSTN IN Reset RESET

32

SEL IN DRAM row/column address switching signal SEL

33 VBLN OUT Vertical blanking signal (CRT) VBLK

34

HBLN OUT Horizontal blanking signal (CRT) HBLK

35 WATN OUT CPU wait

WA

36

COLR OUT Colour sub-carrier wave (4,4361875MHz: PAL) COLR

37

PRCN OUT Printer I/O address select PRC

38

Q1

Display: Address data

output

(Line

Count

Signals)

Ql

l l OUT (Display address

is

indicated

to

the

CG ROM together l

40

Q3 with

PO

-PlO).

Q3

41

NTPL IN NTSC/PAL system switching (PAL=L) N/P

42

BLNK OUT Timer clock BLNK

43 HSYN OUT Horizontal synchronizing signal HSY

44

ABC

OUT

ABC

45 LOAD OUT Character, display start signal LOAD

46

PO

Display address signal

PO

l

~

OUT l

52 P6 P6

53 GND -GND

54 P7 Display address signal P7

l l OUT l

57

PlO

58 S157 OUT V-RAM display/CPU address switching signal S157

59 SYNN OUT Vertical synchronizing signal SYN

60

CLKN OUT Character display shift register clock CLK

8

CUSTOM

LSI

<YTl >

1.

BLOCK

DIAGRAM

CRT

Control

LPHI 0 J

I

l-{

NTPL

AO

A1

A2

A3

A4

A5

A6

A7

A8

A9

A10

0

('

-

9

0

Eh

H

COLR

1/2

1/4

"

/

I

J

I--

IMT

I

I.....-

AND

LOO

SCREEN

POSITION (1)

ABC

r-- SCREEN

POSITION (2)

"

I'

5

~

V.

BLNK

CIRCUIT

~

•

L---

\

11

,

0123

-

~

r--

H. SYNC. (NTSC)

r--

H. SYNC. (PAL)

f----

-

...,

A-C

3

\.

,

8

D-K

\ ,

~

V. SYNC.

CIRCUIT

I

1

1/2

AND

It

I 1/2

-

Y

1/2

9

NTSC

PAL

SELECT

BLNK0

~

a:

w

X

w

..J

0..

i=

..J

::>

::i:

Cl)

w

a:

0

et

f

I -

f

I -

I

1

r

~

-

~

"V

~

"U

~

Y

V

~

"!

"0

CLKN

COLR

HSY

BLNK

HBLN

LOAD

PO

P1

P2

P3

P4

P5

P6

P7

P8

pg

P10

S157

3

CS

DD

SYNN

-0

VBLN

"0

01

02

Q

03

Memory

Management

(1)

IORN

A1

A2

A3

A4

A5

AS

A7

AO

WRN

A15

A14

A13

A12

MRQN

RFSN

RDN

PHI

A11

A10

A9

AB

,...

"

0

~

0

."

0 "

0

-"

.....

" "

0

'"

0

0 "

"

0

'\

-

0

-

:::.

~

'-

0

AND

3

\.

,

r--

4

\,

4

\.

•

-0 PRCN

BLNK

2

Z

'----

0

~

LACH

<C

(f.I

~

Z

w

a..

~

0

U

INH1 • CSDD

INH2

INH3

I-

:;

u RASN

!!:

U

(/)

<C

a:

INH1

')

'"

CSON

AND

INH2

-

WAIT

-0

INH3

CYCLE

WATN

AND

CIRCUIT

CSDN

1

INH2

INH3

AND

CSEN

10

Memory Management

(2)

PH111

WRN

MRQN

RDN

LPH1

NTPL

CL

GATE

VCC

GND

0

Colour VRAM (VRAM-2)

CAS

circuit

1/4

•

MZ-

700 colour infonnation

is

managed character by

character. One byte

of

colour infonnation table is assign-

ed

to

each characters displayed on the

TV

screen.

D7

D6

D5

D4

D3

D2

D1

DO

ATB

FRONT G

FRONT R

FRONT B

Not used

BACK G

BACK R

BACK B

ATB: CGROM

address switch-

ingbit

....

+-_FRONT

BACK

Character iqfonnation

is

stored in address

$DOOQ.

$D7FF and colour infonnation in $D80Q.$DFFF

of

the

VRAM.

11

~------------------------------<1SEL

COLR

NTSC

PAL

select

~-------------In

PH

10

4-3. Memory

mapped

I/O

($EOOO

-

$EOO8)

CPU

memory Controller Function

address

$EOOO

PA

: Output

$EOOl Pe : Input

$E002 8255

Pc

: Input/output mode controller

by bit cell

$E003 Mode controller

$E004

Co

: Mode 3

(square wave rate ge»erator)

$E005 C, : Mode 2

8253

(rate generator)

$E006 C2 : Mode 0

(terminal counter)

$E007 Mode controller

$E008 LS367 and Tempo,joystick, HBLNK input

others

a) Signals around

the

8255

The 8255 Programmable Peripehral I/O Controller assumes

the control

of

the cassette recorder, CRT screen cursor

Port

PA

($EOOO)

PB

($EOOl)

PC·

($EOO2)

Cassette

control

Key data

input

terminal

(8P)

RDATA

MOTOR

M·ON

WDATA

Key data

strobe terminal

(lOP)

Port terminal

PAo

PAl

PA2

PA3

PA7

PB

o

PB

I

PB

2

PB

3

PB

4

PB

s

PB

6

PB

7

PC

I

PC

2

PC

3

PC

4

PC

s

PC

6

PC

7

r---

'-

VBLNK

5560UT

INTMSK

556RST

0

LS

0

\145

-C

B

9 A

I/O Active state

H

OUT H

L

IN

L

OUT -

OUT L

OUT 51..

IN H

IN -

IN

-

IN -

blinking timing, keyboard scan strobe output, and key

return data.

8255

PBO

\

0,

PB7 \

Do

PC7

PC6

AI

PC2

PC5

Ao

PC4

PC3

RD

PCl WR

CS

PA7

RESET

PA,

PA.

PAl

PAo

Control function

}

Keyboud

scan stwhe slgnal output

Cursor blinking timer reset

Keyboard scan data input

Cassette data write •

Timer interrupt disable

Motor rotate control

Motor rotation check

Cassette data read

Cursor blinking timer input

Vertical blanking

0,

AI

8255

RESET

Signal name

556RST

WDATA

INTMSK

M-ON

MOTOR

RDATA

5560UT

VBLNK

•

Output

data handled in the

bit

cell mode. (Port C in control mode)

b)

Cassette controller

Data transfer with the cassette recorder is carried

out

on

PCI, PC4, and

PC5

of

the 8255. Shown next

is

the data

format (Sharp

PWM

method)

of

the cassette tape.

12

1-o1

..

_--464~-

__

...

II.oo

...

_-49

.•

4j.1S----I

..

-+oI

.....

240~-'-

264~'"

, I

"I

I I I ,

;.'

______

_

I

CASE1 LONG

-----

....

--

SHORT

U

368j.1S 368j.1S

--J

'

READ

READ READ

READ

POINT

EDGE

POINT

EDGE t

(Rising

edge

SHORT

starts sampling

(HIGH)

240lls

counter) (LOW) 264lls

LONG

(HIGH)

464lls

(LOW)

494j.1S

READ

POINT

368lls

"LONG"

is

the data written for the bit value

of"

1" and

"SHORT" for the bit value

of

"0".

Data is read

368~

after the rising edge

of

the data. The data is recorded

as

a repetition

of

LONG and SHORT, with the same data

block written twice.

I

SHORT

10

sec

22000

TAPE 1

MARK

LONG40

SHORT40

LONG

TAPE

MARK

LONG

20

SHORT

20

INFORMATION

BLOCK

128

bytes.

1

DATA

BLOCK

Check !SHORT

INFORMA·

E

..

TION

:;,a>

SHORT

sum,

~56

.....

BLOCK

~>

1

2 bytes

~ytes

u.rJ

5

sec

128

bytes

1!N

u

LONG

11000

E

Xl

isHORT

E"

..

as:

DATA

:;,a>

.....

~.rJ

1 256

BLOCK

~>

1

Ibytes

u.rJ

1!N 1!N

U U

LONG LONG

The

information block consists

of

the following:

Name

Byte numbers End address Function Note

ATRB

1 $lOF1 Attribute

NAME

17 $1102 File name (up to 16 characters) CR (OD) at the end

SIZE 2 $1104 File byte size

In

order or low and high order bytes

DTADR 2 $1106 Loading address

EXADR 2 $1108 Executing address

COMNT

124 $1170 Comment Not used

13

I

c) Keyboard controDer

The 8255 writes strobe (key scan signals) on

PA

and

reads key data from

PB.

The table shown below

is

the

key map.

d) Signals around the 8253

The 8253 Programmable Timer generates the buzzer tone

through the counter #(J and keeps the internal timer

function

via

the counters

#1

and #2.

The counter #(J

is

used

as

a square waveform generator

(Mode 3). The counter #1

is

used

as

a rate generator

(Mode

2)

and #2

as

an

interrupt upon terminal count

(Mode 0).

The counter #(J counts the input pulse

of

895KHz which

is

divided by a predetermined factor (musical note), and

is

then supplied to the amplifier to generate sound. The

counter

#1

receives

an input pulse

of

15.6KHz and creates

a

pulse

on OUTl every second. The counter #2 counts

those pulses

and

OUT2 turns to a high

level

12

hours

after.

As

OUT2

is

connected to the

CPU

interrupt pin,

it then goes into an interrupt processing routine.

8253

D7

Do

14

OUT2+----TO

CPU

INT

OUT1

ClK1

BlNK

05.6KHz)

OUTO

sp,

ClKO

895KHz

5.

DATA

RECORDER

5-1.

Data recorder (MZ-lT01)

Data transfer with the recorder is carried out

via

the 8255.

The

read data

is

sent out through

the

port

Cl

and the

write data

is

received through the port

C5.

The motor

on/off control

is

carried out

via

the port

C3

and that

activation

of

the motor

is

confmned through the port

C4.

The

signal

SENSE

goes

low when FF,

REW,

or PLAY

pushbutton

is

pushed on the

MZ-}

TO

I.

Block

diagram

+5V

Control

circuit

• Cassette specification

Method

PWM

recording

method

Rated power

5V

± O.25V

Wait: 2mA

Rated

current Record:

210mA

(TEAC TEST TAPE)

Playback:

150mA

(TEAC TEST TAPE)

Transistor x 5

Semiconductors used IC x 2

Diode

x4

Tape used C30 -C90

Rated

tape

speed 4.75cm/sec

Tracks 2 tracks, monoral

Motor

5V

electronic governor

motor

Bias DC

Erasure

DC

Standard playback

point

lmsec

-

500

sec

Nominal

input

L: O.4V, max.

level and H: 2.0V, min.

input

impedance

R~cording

terminallOkn

min.

Nominal

input

level L: O.4V, max.

H: 2.0V, min.

Erase

head

------

Record/playback head TAPE

Differentiation

circuit

o-

__

~

______________

~

__

~

____________

~

____

~03003

R3003

R3004

Amplifier

03003

SW3002

Mechanically

interlinked

switch

WRITE

READ

15

Amplifier

Amplifier/

circuit

+5V

Limiter

03001

-~---!

circuit(1/2),

03002

IC3001

Waveform

shaping

circuit

(2/2),

IC3001

Amplifier

circuit,

03004

I

iv1Z

700

Troubleshooting procedure

Phenomennon

CD:

Motor

and

tape

do

not rotate,

when

the

PLAY

button

is

pushed.

Check

if

M+

and

M·5V

are

in

supply.

NO

Motor

failure

Check

if

the SW302

interlinked

with

the

P

LAY

push

button

is

active.

Phenomenon

@:

Program

can

not

be

saved

Check

if

the

SW3OO1

interlinked

with

the REC push

button

is

properly

operating when the

REC

pushbutton

is pushed.

Check

if

+5V

on

Cl)

.

NO

itch

failure

heck

if

signa

is

on

from

the

OK

terminal

!J).

OV: when

SW

is

on

+5V:

when

SW

is

off

NO

Check

+5V

on

REMOTE

terminal

@.

Check

the

+5V

input

voltage. Check

R3009.

OK

Check the

motor

lead

wire

(REM)

and

the

motor

transistor (2S0468)

Check

if

voltage is

on

to

the

base

of

the

remote

control

transistor

of

the CPU board.

Check

the

CPU

board.

Check

if

the signal

is

on

to

the

base

OK

of

03002.

Failure

of

SW3OO1.

Check R30OS.

signal

is

on

to

the recor

OK

ding

head.

OK

NO

Failure

of

the recordl

playback head.

Contact failure

in

SW3OO1.

Check

03001

and

03002.

Check

if

voltage

is

on

to

the

erasure head.

Phenomenon

®:

Program

can

not

be

loaded

or

resulted

in

error

Check

if

a

waveform

is

on

the terminal

®.

OK

Check

the

1...----1+5V

NO

supply.

No

waveform

with

too

much

noise.

NO

16

Check

if

the erasu

re

head

should have been inactive

due

to

failure

of

SW3001 .

Check peripheral

components

around

03003

and

for

azimuth

maladjustment

of

the recordI

playback

head.

Mechanical adjustments

RECORD/FAST FORWARDjREWIND torque measure-

ments

1.

Set the torque measuring instrument on the cassette

tape recorder.

2.

Torque

value

under each mode must be

as

follows:

Position Torque measuring Value

cassette

PLAYBACK

TW-2111

30

'"

70gram·cm

FAST

TW-2231

60

'"

160gram·cm

FORWARD

REWIND

TW-2231

60

'"

160gram·cm

Record/playback head azimuth adjustment

1.

Set the instrument

as

shown in Fig. 4-2.

2.

Playback the test tape (Teac's

MTTlll,

recorded with

3KHz signals).

3.

Adjust the head azimuth adjusting screw

so

that the

reading on the digital voltmeter

is

at its maximum

value.

Cleaning

of

head

The

head

is

critical for a proper performance

of

the tape

recorder. Dust on the head, capstan, pinch roller, etc.

impedes proper recording and playback. Open the cassette

holder, take out the tape, push down the

PLAYBACK

pushbutton, then clean those components.

If

you can

see

any oxide deposit, clean them using a cotton bud

damped with alcohol.

RECORD

pushbutton can not bepushed in

The

RECORD pushbutton can not be pushed in,

if

the

erasure protect tab

of

the cassette tape

is

broken. Forcible

depression

of

the button may result in machine failure.

17

Tape speed adjustment

1.

Connect the wow-flutter measuring instrument to

:f#!,

of

the

CNW3001

connector.

2. Playback the test tape (UKOG-0119CSZZ, MTT-1l3

recorded with 8KHz signals).

Use

the middle part

of

the

tape for the test.

3. Adjust the

semi-fix~

resistor located on the Motor

Board

so

that the playback frequency should become

8000 ± 250Hz.

Test tape,

MTT-113

Pinch roller

Collector

of

transistor

03003

Digital

voltmeter

Figure 4-2.

Head

MZ~700

Cassette

recorder

waveforms

Primary stage amplifier

output

wavefonn Operational amplifier

input

wavefonn Operational amplifier

input

wavefonn

CD

® ®

/1

AWl

IJ

1.

~

6mv~

1.8V

r

vpp

pp

T ov

Operational amplifier

input

wavefonn Operational amplifier

output

wavefonn

Output

wavefonn

@ ® ®

Tt

f1

" " T T

1.SVpp 4Vpp

sVpp

1

\lV""~'"

1 1

Recording

input

wavefonn Recording signal amplified wavefonn Recording signal amplified wavefonn

(J)

® ®

T~

---

T-

r

~

T

~ ~

1.SV O.9V 1.8Vcc

pp pp 1

~

....

1

'-

'--

'- '-

....

Head

input

wavefonn

@

I\

~~

\

1\

V/ V oFigure in a ciele represents the waveform test point on the circuit diagram.

18

~\;1Z

700

5-2.

External recorder playback circuit

When

the external recorder

is

used, connection

is

made

with the 8255

by

shorting P-12. In this condition, the

write data (8255

PC

output)

is

differentiated and sent

to the recorder.

In

the case

of

read, the signal peak

is

chopped by

DI

and D2 (about

O.6V),

amplified in the

1.2V limiter (about 1.2V), then amplified

to

5V in the

next stage amplifier. The phase

of

the read signal may

be

inverted with the tape switch after this

is

to compensate

for phase difference owing to the head

of

the recorder.

When

proper operation

is

not attained with an external

recorder, adjust the volume control and the tone control

knobs to optimum positions. Those which incorporate

treble and base for tone control should preferably be set to

a flat condition, and those with only a tone control knob,

should be set to a high condition.

6.

COLOUR ENCODER

6-1. Colour encoder

• The encoder unit should

be

replaced

as

a unit part.

• Input signals

• COLOR

•

CSYNC

•

HSYNC

•

VSYNC

• R

• G

• B

Colour sub-carrier

wave

frequency

Composite synchronizing signal

Horizontal synchronizing signal

Vertical synchronizing signal

• CVIDEO

'X.

Rear

view

,~

B/W-Colour

sw

I ++

6+

?I

RF

CH1-

VIDEO

8pin

OUT

CH2

OUT

Din

SW

19

• 8-Pin DIN connector

I VIDEO

2 GND

'5'

VSYNC

4

HSYNC

'3'

CSYNC

6 R

7 G

8 B

7~~

3 •

S'

8 4

2

• Whenever there

is

any problem with the display check

if

all

signals are supplied to the colour encoder. Check

the waveform

of

VIDEO OUT.

* Problems may arise

if

the colour TV

is

improperly

adjusted.

Signal waveform

of

VIDEO OUT (figures in the drawing

represents nominal values)

0-

--

64

Sharp MZ-700 Series User manual

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