Hitachi MB-6890 User manual

HITACHI PERSONAL COMPUTER
MB’6890 SERVICE MANUAL
I
R0.3012 98
All manuals and user guides at all-guides.com
all-guides.com

HITACHI PERSONAL COMPUTER
MB-6890 SERVICE MANUAL
ev. O, 30.1.2.1
All manuals and user guides at all-guides.com

Index
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
a
0
a
o
0
Q
U
0
Q
u
o
0
0
0
0
»
9
General .2
Features .2
Specification ........ 1,2
The name of each block .. .6
Function of I.C’s used ........ »»3
10
Explanation of the circuit .. ..
Memory map ..Q ....¢iii@;i== .. 31
Adjustment ..... ... 82
Service points ................. .. 85
The usage of inbuilt switches .. ... 87
Trouble shootings ............ ... 91
Operation check method ... ...102
Basic circuit diagram
Basic P.C.B. layout
Waveform of each block
Parts list
1
All manuals and user guides at all-guides.com

(Y4
l. General
MB-6890 is the multi purpose personal computer, having BASIC high
language for programming.
The h i g h d ‹ m ‹ H d
and requirement from the users can be achieved by
built in interfaces for future expansion of the system.
2. Features
-Seven colour graphic display with separate command for the char
acters and their background colour.
-High resolution colour display up to 640 x200 pixels
is used for graphics and the combination of characters and gra-
phics can be used at the same time.
-Powerful "Extended BASIC" and "Monitor program" is stored in ROM.
-Standard interface for cassette tape recorder, printer and
Light pen is attached as standard.
-Built in interface connectors for future system expansion.
3. Specification
3.1. General specification
iIC Wl43pcs(CPU), 4pcs(Power unit)
Transistor 7pcs(CPU)[ 8pcs(Power unit) p
Diode lOpcs(CPU), 25pcs(Power unit)
Speaker output O.4W
_Speaker 6x9cm(l6 ohm) _.l pcs
I
Input/Output Cassette tape recorder connector(CASSETTE)
Light pen connector (L/PEN)
Colour display connector(COLOR)
Monocrome display connector(B/W)
RS-232C connector(RS-232C)
Printer connector(PRINTER)
*
C
Built in expansion connectors(I/F-l**I/F-6)
connector Memory expansion connectors(RAM3,RAM4)
__ ,
A
Power AClOOV(5O/60 Hz)
.g g_
.C
,
r
Power consumption 3OW( without any expansion of memory OT
interface card)
_
_
Dimension 45.0(W) x12.5(H) x5l.5(D) cm
W e i g h t
A
7kg
level
All manuals and user guides at all-guides.com

3-2_ Connector pin signal.
(1) Cassette Tape Recorder(CASSETTEL
’W |
direction Signal pin pin Signal direction
(CPU -out) No. NO. (CPU -out
--~ remote 12GUD +--~
* - - * record 34lremote * - ’ *
1* - ‘ |Play 561_
(2) Light Penn./PEN)
direction Signal pin pin Signal direction
(CPU -Out) NO. NO. (CPU -Out)
--- 7675? 12f137§vV _ -
------ +5V 34LP VCMP ‘
----
--1* GND 5
(3) Colour displav(COLOR)
direction .pin pin .direction
(CPU -out) Slgnal No. No. Signal (CPU -out)
---» +I2V 12GND #-~~»
-- T>‘§‘13§TT 34QW --
-- T565 5
’
6R---»
-- G1 s B--»
(4) Rs-232C Int rfacems-232c)
direction _pin pin .direction
(CPU -out) Signal No. No. Signal (CPU -out),
‘
*- 12TxD ---*
*--- RxD 3 4 RTS --~*
--- CTS se-
i
r-- GND 78DCD - -
- 9 10 --
;n4|1
-11 g12 -
-~ 13 14 --
’- 15 16 --
-- 17 18 --
-- 19 20 --
-- 21 22 --
-- 23 24 --
}-- 25 -
All manuals and user guides at all-guides.com

(5) PRINTER INTERFACE(PRINTER)
directien .min Qpin _
1direction V
(CPU -out) S3151
filo. No. Signal (CPU -out) 1
--~ STRB 12D,, -_-
--» D, 3
_
4D, ~_-~
---» D, Q5’_ 5D. -_»
--~ D, _
7QsD. --»
-- D,
_
9
’
10 A i ; T < --
--- BUSY
_
11 Q12 -
QQ-
,13 QL4 ,
-
II
-
_
15 15 GND --»
-17
0
18 -
Q
-19 20 1 -
-21 22 1 -
-23 24 -
-25
26 -
-27 QI 28 -
-\29 Q)
30 -
-31 Q32 -
»-_- GND 33 Q34
_
-
-
0
as Qas -
(5) Memory expansion (RAM3, RAM4 )
direction *Z *1 p i 1 1 Q
in *I *Z directicn
(CPU _QU_tI_ RAM4 RAM3 NO_ QO_ _
RAM3 RA114 _(CPU wut,
----» +12v Q+12v 1QQ
2GND QGND »---
-_» +sv Q+sv 3
‘
4‘ -sv Q-sv ---
--» D0 QD0 5Qe
’
D, DQ Q--
--- D, QD, 73QD1 D, Q---
--~ D. QD. 910 QD, D, --
---~» D. D. 11 QQ
12 QD, D, Q---
»----- A R QARD 13 Q14 QAR, AR, --
---» AR, QAR, Q15 16 QAR, AR, --
--~ -AR. QAR. _
I7 LE 18 1AR, AR,
_
»--
V-» AR, 3AR, 19 ’Q20 Qmis RAS ~-»
--» CASQHZ §CAS’/52 21 22 Q1?/E1 WEE Q2- --»
*_-~~
-» ROSFKIL fR 0 1 1 - ‘ 1 ‹ i ’ E
23 z24 QRuw 0UT§ww DUTQ -s--~»
_
--
___ 1 1 g D s E 1 ; e
A 8 5 - A S E I _ . _
25 .f 26 FA,11§"sE1I;
AE SEL Q’---
_i;N11;*Q_‘GND
0
2 7 Q _ _
28 Q»12v Q»12v ~--~-»
*l, £143 is for the address (58000
*2. RAM4 is for the address (SCOOO SEFFF)
All manuals and user guides at all-guides.com
all-guides.com

75 Ihterface expansion (I/F-I I/F-6)
i
direction
i
_ipinppin ,direction
(CPU -out) t
Signal No. Signal (cPU- out)
-4-_~ +5v 112 GND ---
-~-» iD.. 34D, ---»
-- D, 5i5D, --»
---» D. 1
1
sD5 ---
--» D1 9
’
10 D, »--»
--~ A,, 11
‘
12 A, ----
1---A
A{A, Q13 Q14 A, |--- ~{
---» A. 15 16 A. --»
--- A., 17 18 A, --»
4--» A. 19 20 A. ---
---- A . 21
A
22 A,, ---
--- A., 23 24 A,, --»
--» A,. 25 26 A,, --»
-_- BA 27
’
28 BS -~
---
‘
E555
‘
29
"
so EXROM-KIL --~
--- 11/w IN 31
‘
32 E356 --~
---» R/w OUT 33
A
34 VMA our --»
--» 1-: as as Q---»
1
--- ‘1§‘§ 37 38 FH ----
--- T55 as 40 mi ---
EXE4142WTTEE.--- EXE 41 42 WTTEE. ---
-- ETA’ 43 44 §XN‘1FSW ---
--» HALT ACK 45 46 SOUND IN ---
---»
‘
ISMCK 47 48 GND f--»
--- 2Mc1< 49 so GND 1--»
--~ -5V 51- 52 ‘}§;‘§‘{ffR)"§" --->
-1- -12v 53 54 +12V ---»
---- GND 55 56 +5v --
5
All manuals and user guides at all-guides.com

4. Explanation of the each part
*Operation panel
._ ~»,‘
_. .,.., :_ __._
~"’"T M_‘ _ - »-=
’
V" f_ _’
"
I
*operation panel
~ W " C 5 G 5 ? ? 7 i W i ~
EI /<@@fafi'H switches
"fHfi@ ~
__ _
~are inside the cover)
.,’i’;i;@;_:_
N
_
-
_
’i
_
V
keyboard
*
\
(Q
eowsfz S W 5 - C C h i
votufvia j!MopE5wj_tC1q=?
RESET Switch
0} O
_O,,,¢¢- if \: ..;¢¢ msn asssr
WN MIX
POWER VOLUME MODE RESET
Powaaon display light
l) Power switch;
Push the switch then power is on with red light on. Push the
switch again then power is off.
2)VOLUME :
Control the loudness of the Click sound of the keyboard and
speaker volume.
3) MODE switch;
This switch selects characters/line mode ("1"=80 CH./line;
"o"=ao CH./line).
4) RESET switch;
RESET is triggered by this switch, and stops executing the
BASIC program, and returns to command level.
A
All manuals and user guides at all-guides.com

*Rear, Connectors
Following six different interfaces are built in as
standard in M -6890.
1
*
p. mm .H~mi»;_ __‘_ _,_ ,
_
{_~ ,
~ . ’ + = .
’ . ’ Q ~ ’ z ~ : ‹ :
’_ ; ~ » ~ - =_f- :""’ ~’;» n " ¢ ’ 1 ~
‘’»-
> ’ ~ 1 ; . " 1 ’ - : F i - k c ’ - ’ AE§»:.-»;_ _V T _ » " j ! , , 2 5 f " ‘
;-¢_ ,_ . , ‘?’
g’ gf =
_ : i 2 , [ § » ; : i ; ’ § ’ + - ; § M ; i ? , ; @ 5 ’ , 2 f + l ; , 5 = i ! " 3 3 Z ’ § i : f 1 a a : H t l r f . " -
M; i ? , ; @ 5 ’ , 2
f+l; , 5 = i ! " 3 3 Z ’ § i : f 1 a a
:Htl rf."-
, f
-if » ¢ ~ f = t . = , \ 1 g f f , . ; - ~ - - , » f ’ ~ q ’ - .V ’
~~_ "F ~’
$Cassette tape recorder
(CASSETTE) ,
@Interface. /W
ex asion _
(I/F -1~»,$-513 \/
Qlight pen
(DPW)
__ Light pen
(BAP-3700)
fiCblour monitor """i -
(coLoR>
colour monitor
(c14-2170>
@MonochromeMonitor’ H
(ww) B
Green monitor
(KIZZDSSP)
5
ins-zazc.
Rs~z32c ..
()Other equipment which
has RS-232C interface.
isprinter
(PMNTER)
The six pairs of interface expansion connectors and two
’
connectors are inside the MB-6890.
pairs of memory expansion
7
All manuals and user guides at all-guides.com

5. IC’s in use.
Type No.
Q
circuit no. function
Mpu HDeso9P/MCeao9L 1C1 central Pf C@SSif19 Unit
Hmssossp rcse CRTC
L.Sl HD4ea21P Q
LCSS Q PIA Q
HD4sssoP ICS4 ACIA
Icse, 1Cs1 Icss 1Cs9
1Cso,1Cs1 xcsz [css
RAM HM4716AP-1 IC54’ IC65’ IC66 IC57
RAM
ICss,1Cs9 Icvo IC71
IC12, IC73, IC14, IC75
1C1s,
/mnzsasc-ssc Qrcs BASIC Rom Q
ROM uPD2364C-331 IC4 BASIC Rom Q
uPD2364C-332 I C S BASIC, monitoraom
yPD2332C-328 IClO7 \characters,graphic ROM
HDHLSODP 1C2s, rczs, IC47, IC12s
2_
IC129, IC145 lnput NAND gate
Icaa, IC34, 1C4e, ICQ4
" D 7 L S " 2 P
[C142 2input NOR gate
HDNLSMP IC23, IC31, IC44, 1C91
inverter
IC100
HD74LS05P IC22, lC95, ICIOS open collector inverter
xczs, Icas, xC49, IC92
HD74LS08P IC96, IC136, IC143 2 input NAND gate
1C14s
HD74LS1OP 1C21 rC4s 3input AND gate
HD74LS11P Qrclss 3input AND gm? Q
H D 7 4 ~ 5 1 4 P [Cm Q
Stghmitt trigger inverter
V
HD74LS30P rcso, ICIO4 Sinput AND gate Q
HDm.S32P 1C29, 1C3z, IC97, 1Cl44] 2input NOP- gate
IC14, IC1s, ICI7, IC1s
HD14Ls74AP Icso, xCs3, xC93, IC99 Dtype flop flip
1C1o3 IC126. ICl30
Q
HD14LSseP Azcss, [C131 eX_Or qate Q
1C1s, IC101. rC1o2 Q
HD74LS93P ‘ICl22 1C123, rC124 4bit 2decimalcounter Q
IC\34
’
!
HD74LSI25AP ICQ4, me bus buffer gate Q
HD14LS13sP Q1C12.
IC13
_d&m’dQr_Q/demltiplexer
HD14LS139P ICU. IC137 -» »~ Q
Hm4LS1sw Q
xC9o
’
deselecwr/multiplexer
Q
HD74LS1_53P Q1C112
QQ
.» ~ 1
3
All manuals and user guides at all-guides.com