Atari 1027 User manual

Atari 1027 Printer 5-i
Field Service Manual

Atari 1027 Printer ii
Field Service Manual
ATARI
1027TM PRINTER
FIELD SERVICE MANUAL

Atari 1027 Printer iii
Field Service Manual
Atari believes that the information described in this manual
is accurate and reliable, and much care has been taken in its
preparation. However, no responsibility, financial or
otherwise, shall be accepted for any consequences arising out
of the use of this material. Information contained herein is
subject to change. Revisions may be issued to advise of such
changes and/or additions.
Correspondence regarding this document should be forwarded to
Director of Technical Support, Consumer Product Service,
Atari, Incorporated, 845 W. Maude Avenue, Sunnyvale, CA 94086.

Atari 1027 Printer iv
Field Service Manual
TABLE OF CONTENTS
Section Title Page
INTRODUCTION v
1
THEORY OF OPERATION 1-1
Overview 1-1
User Interface 1-3
Mechanical 1-4
Case 1-4
Type Selection 1-7
Type Wheel Movement 1-7
Hammer Movement 1-7
Hammer Strike 1-7
Paper Feed 1-7
Character Sensing 1-7
Type Wheel Home Position Sensing 1-7
Hammer Home Position Sensing 1-8
Ink Roll Mechanism 1-8
Manual Knob and Paper Lock/
Release Lever 1-8
Electronic 1-8
Power Supply Circuit 1-8
Microprocessor 8049 (MPU) 1-9
Interface Circuits 1-9
Wheel, Hammer Motor Drive Circuit 1-9
Hammer Select Solenoid Drive Circuit 1-9
Character Select Solenoid Drive Circuit 1-10
DC Motor Drive Circuit 1-10
Sensor Signal Circuit 1-10
Power-on Reset Circuit 1-10
Oscillator Circuit 1-10
2
TESTING 2-1
Equipment Required 2-1
Diagnostic Procedure 2-1
Setting up the 1027 for testing and
using CPS Diagnostic Diskette with
the file T1027.BAS 2-1
Test for Character Skew 2-5
3
DISASSEMBLY/ASSEMBLY 3-1
4
SYMPTOM CHECKLIST 4-1
5
DRAWINGS AND PARTS LIST 5-1
6
SERVICE BULLETINS 6-1

Atari 1027 Printer v
Field Service Manual
LIST OF ILLUSTRATIONS
Figure Title Page
1-1 1027 Printer Block Diagram 1-2
1-2 1027 Printer Controls/Indicators 1-3
1-3 1027 Printer Back View 1-4
1-4 1027 Printer Final Assembly 1-5
1-5 1027 Printer Mechanical Assembly 1-6
1-6 Power Supply Circuit 1-9
2-1 All Function Test Printout 2-3
2-2 Standard Character Set 2-3
2-3 International Character Set 2-4
2-4 Standard Character Set With Underline 2-4
2-5 Direction Print Check 2-4
2-6 Character Skew Printout 2-6
5-1 1027 Printer Schematic 5-3
5-2 1027 Printer Silkscreen 5-5
5-3 1027 Printer Final Assembly 5-7
5-4 1027 Printer Mechanical Assembly 5-9
LIST OF TABLES
Table Title Page
4-1 Symptom Checklist 4-1
4-2 Diagnostic Table 4-3

Atari 1027 Printer vi
Field Service Manual
INTRODUCTION
The Atari 1027TM Printer Field Service Manual is a reference
guide for the service technician. The information presented in
this manual, when used in conjunction with Atari training,
enables you to repair and maintain the 1027 Printer.
This Field Service Manual is organized in six sections:
•THEORY OF OPERATION - Overview of how the 1027 Printer
works and what its basic assemblies look like.
•TESTING - Review of tests available for diagnosing 1027
Printer problems.
•DISASSEMBLY/ASSEMBLY - Procedures for disassembling and
assembling the 1027 Printer.
•SYMPTOM CHECKLIST - Failure information to aid in
diagnosing 1027 Printer problems.
•DRAWINGS AND PARTS LIST - Silkscreen, schematic, assembly
drawings and a breakdown of parts used to repair the 1027
Printer.
•SERVICE BULLETINS - Section to be used to hold Field
Change Orders, Upgrade Bulletins and Tech Tips.

Atari 1027 Printer vii
Field Service Manual

Atari 1027 Printer 4-1
Field Service Manual
SECTION 1
THEORY OF OPERATION
OVERVIEW
The ATARI 1027TM Printer is a letter quality impact printer
that averages 10 characters per second. It is a hard copy
output peripheral intended for use under the control of the
ATARI 400TM, 800TM, 600XLTM, 800XLTM or 1200XLTM computers. It
connects directly to the SIO peripheral port of the computer
(no interface is required). The printer mechanism is a type
wheel assembly. All firmware is resident in the printer and
executed by an onboard microprocessor which controls the
functions of the printer.
Figure 1-1 on next page show a block diagram of the functional
flow of the 1027.

Atari 1027 Printer 4-2
Field Service Manual
Figure 1-1. 1027 Printer Block Diagram
BUFFER
BUFFER
BUFFER
BUFFER
MPU
8049
Transistor
Array
Wheel
Stepping Motor
Wheel
Stepping Motor
DATA IN
DATA OUT
COMMAND
5V/READY
Character Select
Solenoid
Hammer Select
Solenoid Driver
DC Motor
Character Select
Solenoid Driver
Hammer Select
Solenoid Driver
DC Motor Driver
Hammer Home Position
Sensor Circuit
Hammer Home
Position Sensor
Wheel Home Position
Sensor Circuit
Wheel Home
Position Sensor
Wheel Timing
Signal Circuit
Wheel Timing
Zero Timing
Signal Circuit
Zero Timing
Voltage
Regulator
AC
Adaptor
5V
6V

Atari 1027 Printer 4-3
Field Service Manual
USER INTERFACE
Figure 1-2 shows the location of the Controls/Indicators.
Figure 1-2. 1027 Printer Controls/Indicators
The Controls/Indicators and their functions are:
Access Door - Allows access to the plastic gears for
lubrication.
Paper Lock/Release Lever - When this lever is moved back
(direction of arrow) the paper chute opens to
allow insertion of paper. When this lever is
moved forward, there is pressure against the
platen and paper is fed.
POWER - The microprocessor is reset when the POWER button is
pressed.
Power-on Light - The LED indicates that power to the unit is
ON.
Manual Knob - Turn the manual knob to move and position the
paper in the printer.