Epson QX-10 User manual

TECHNICAL MANUAL
TROUBLESHOOTING
EPSON
08290002-0

TECHNICAL MANUAL
TROUBLESHOOTING
QX~O
This Technical Manual provides technical information on the structure, maintenance, and repairs of
the QX-10.
For the details of the operation, refer to the Technical Manual of QX-1 0 (Principles of Hardware Oper-
ation).
Major technical modifications, if made
in the future, will be notified through Service Bulletins, and the
Technical Manual should be revised accordingly. The.details
of the Manual are subject to change
withOl,!t notice.
All the information given in the Manual concerns the QX-1 0
to others.
All rights reserved. No part
of this publication may be reproduced, stored in a retrieval system, or trans-
mitted,
in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, with-
out the prior written permission by EPSON CORPORATION.
Copyright © 1983 by EPSON CORPORATION
Nagano, Japan

CONTENTS
CHAPTER 1 GENERAL
CHAPTER 2 DiSASSEMBLY
AND REASSEMBLY
CHAPTER 3 ADJUSTMENT AND MAINTENANCE
CHAPTER 4 REPAIRS
CHAPTER 5 TROUBLESHOOTING

CHAPTER 1
GENERAL
CONTENTS
1.1 Features........................................................................................................... 1-1
1.2 Hardware Configuration................................................................................ 1-1
1.2.1 General................................................................................................... 1-1
1.2.2 Hardware ............................................................................................... 1-1
1.3 Specifications .................................................................................................. 1-2
1.3.1 External Dimensions and Weight ......................................................... 1-2
1.3.2 Environmental Conditions .................................................................... 1-2

1.1 Features
The OX-1 0 is an all business computer system. It consists of a Z80A-compatible CPU, a memory of
256 KB maximum, two floppy disk drivers of double-sided, double-density, 5-1/4" disks, and a 12"
full-graphic CRT display with a resolution of 640 by 400 dots.
The standard configuration includes a programmable timer, Centronics-compatible
printer interface,
RS-232C interface, C-MOS RAM backed up by battery, clock and calendar, and separate keyboard. It
has five card slots which permit installation of optional cards as required.
Optional cards available include character generators
of varying fonts, IEEE-488 interface, optical fib-
er interface,
color CRT interface, and pulse transformer interface.
1.2 Hardware configuration
1.2.1 General
The OX-1 0 is composed of three units: the main system unit, the keyboard unit, and the monitor unit.
The main system unit,
the heart of the QX-10 system, includes the main circuit board, sub circuit
board, power supply, two 5-1/4" floppy disk drives developed by Epson, and five slots permitting in-
stallation
of optional cards.
The keyboard
unit is connected to the main system unit with a curled cord through which signals may
be transmitted in any direction.
The standard
monitor unit is a 12" high resolution green monitor capable of displaying bit images.
1.2.2 Hardware
Main system
CPU
Memory
Clock
Speaker
Interfaces
DMA
Interrupt levels
Counter/timer
FDD
Card slots
Monitor
Keyboard
.uPD780AC-1 (Z80A compatible, 4 MHz)
RAM :
256 KB (maximum on main board)
VIDEO RAM : 128 KB (maximum on CRT board)
C-MOS RAM : 2 KB (standard, backed up by battery)
EPROM : 2/4/8 K8 (for IPL)
C-MOS real-time clock (backed up by battery)
Permanent magnet speaker
Printer interface (Centronics-compatible)
RS-232C communications interface
7 channels
15
6 channels
5-1/4" FDD x 2
320 KB x 2 drives
48 TPI, double sided & double density
5
1 2" green monitor
640 x 400 dots
ASCII, HASCI
1-1

1.3 Specifications
1.3.1 External Dimensions and Weight
(1) External dimensions
Main system unit ca.
Green
monitor unit ca.
Keyboard
unit ca.
Optional card
(W)
50S
312
50S
(510)
2S0
(2) Weight: approx. 1Skg
1.3.2 Environmental Conditions
x
x
x
x
(1) Temperature .................... during operation
storage
(2) Humidity........................... during operation
storage
(3) Resistance
to shock ........ during operation
storage
(4) Resistance
to vibration.... during operation
storage
MainSY~
(0)
340
340
224
80
(H)
x 103 (mm)
x 270 (mm)
x
48 (mm)
(mm)
:
5°C to 40°C
: -30°C to 70°C
: 20 - 80% (no condensation)
:
10 - 90% (no condensation)
: max. 1
G, 1 msec
: max. 5
G, 1 msec
: max.
0.25 G, 5-50 Hz
: max. 3 G, 5-50Hz
Greeninitor unit
Fig 1-1 Hardware configuration of QX-10
1-2

Q10GMS
Board
,uP0765
(Channel A)
MPD7210
AC
Q10PS
(Channel B)
IN
board
JLPD8255
Fig 1-2 Block diagram of main component
1-3
U9h8
CRT
~
FOO (SO-321 )
Keyboard
RS-232C
Printer
(centronics type)
Open card

(A) Q10S SYM board
This is a main control board including CPU, compatible with Z80A, Z80A family LSI and main memory.
Name Model Q'ty Function
CPU .uPD780C 1
CPU (4MHz) compatible with Z80A.
DMA controller 8237A
2 Provided
with total of 7 channels for FDD, moni-
tor and options.
Interrupt controller 8259AC
2 Controls
the interrupt priority of total 15 levels
interrupt including PWD output keyboard inter-
rupt.
Interval timer
8253C 2 Controls
the boud rate of keyboard clock and
RS-232C.
Serial controller
7201C 1 Allocates channel a to the keyboard and B to
RS-232C, and controls serial data transfer with
CPU.
Printer controller
8255AC
1 Provided
with an 8-bit parallel port. Acts as an
interface
with printer conformable to Centronix.
Real time clock 46818P
1 Provided
with clock and calendar functions.
Floppy
disk controller
765AC
1 Interface
with FOO (SO-321 )
I/O selector LS154 1 Accesses each I/O point by decoding the 4-bit
low order address (A2 ,... A5) of CPU.
Main memory 416/4164
8 Dynamic RAM is used.
32
Provided with 4 banks maximum.
P-ROM
2716/32/
1 StoresIPL programs.
64
C-MOS RAM
449
1 Protects
the data on power failure. (Backed up by
an NiCd battery.)
Table 1-1 Primary configuration of Q1 0 SYM
1-4

Fig. 1-3
1 ,uPD780C (Z80A compatible CPU)
2 8237 A (Programmable DMA Controller)
3
8259AC (Programmable Interrupt Controller)
4
8253C (Programmable Interval Timer)
5 7201 C(Multi-protcol Serial Controller)
6
8255AC (Programmable peripheral Interface)
7 46818P (Real-time clock plus RAM)
8
765AC (Programmable Floppy Disk Controller)
9
LS 1 54 (I/O Selector)
10 416/4164 (D-RAM)
11 2716/32/04 (P-ROM for IPL)
12 449 (C-MOS RAM)
1-5

(B) Q10 GMS board includes graphic display controller
The board includes graphic display controller ,uPD7220 and V-RAM, and controls display of the green
monitor.
Name
Graphic display
controller
Video RAM
Character generator
Model Q'ty Function
7220 1 A display controller
with high speed drawing and
magnifying functions.
416/4164 16 Dynamic RAM is used.
2732/64
1
ROM storing display fonts to be sent to the dis-
play unit.
Table
1-2 Primary configuration of Q1 0 GMS
Fig.
1-4
1 7220 (Graphic Display Controller)
2 V-RAM
(16/64 k bit dynamic RAM)
3 P-ROM (Character Generator)
1-6