Centronics 101 User manual

MODEL 101 PRINTER
MAY 1978
Centronics No. 37400010
Rev. H
I:EnTROnll:S
data computer corp.
HUDSON, NEW HAMPSHIRE 03051
TELEPHONE (603) 88_3 -0111

MODEL 101 PRINTER
THE INFORMATION CONTAINED HEREIN IS
PROPRIETARY AND IS NOT TO BE RELEASED
OR REPRODUCED WITHOUT WRITTEN PER-
MISSION OF CENTRONICS data computer corp.
CEnTRoniCS
data computer corp.
HUDSON, NEW HAMPSHIRE 03051
TELEPHONE [phone]

TABLE OF CONTENTS
SECTION 1
INTRODUCTION
SECTION
1.1
1.2
1.3
1.4
1.5
2.1
2.2
2.3
4.1
4.2
4.3
4.4
4.5
4.6
4.7
General Description.
Logic
Flow Diagram
Printer Operation
1.3.1 Character Printing
1.3.2
Paper Movement .
1.3.3 Special Functions
Specifications Summary
Physical Description
SECTION 2
AND 3
INSTALLATION AND OPERATION
Site Preparation . . . . . . . .
Shipping Crate. . . . . . . . .
Paper Guide and Stacker Assembly.
Introduction . . . .
Basic Timing . . . .
Initializing the
Printer.
4.3.1 Prime Circuit
4.3.2 Select Circuit
Loading Data . . .
4.4.1 General
4.4.2 Data
Strobe.
4.4.3 Acknowledge
4.4.4 Busy Timing
SECTION 4
THEORY OF OPERATION
4.4.5 Clocking I
nput Data Into the Buffer
4.4.6 Function Decoder .
Character Printing . . . . . . . . .
4.5.1 Initiating the Printer Operation . .
4.5.2 Print
Head Motion . . . . . .
4.5.3 Character Registration
and Timing
4.5.4 Character Generator (ROM)
4.5.5 Print
Head Operation ....
4.5.6 Power Driver Circuit . . . . .
4.5.7 Terminating the Printing
Operation.
Paper Movement . .
4.6.1 Line
Feed
4.6.2 Form Feed
4.6.3 Vertical Tab
4.6.4 Vertical Format
Unit
4.6.5 Line Feed Solenoid Driver
Special Functions
4.7.1
Bell.
2.7.2 Delete. . . "
PAGE
1-1
1-2
1-3
1-3
1-4
1-5
1-6
1-7
. . 2-1,
. . 2-2
.2-3/2-4
4-1
4-3
4-3
4-4
4-6
4-8
4-8
4-8
.4-10
.4-10
.4-12
.4-14
.4-16
.4-16
.4-18
.4-18
.4-21
.4-21
.4-22
.4-24
.4-24
.4-25
.4-25
.4-27
.4-27
.4-29
.4-29
.4-29
.4-31

TABLE OF CONTENTS (Cont'd)
SECTION
4.8
5.1
5.2
6.1
6.1.1
6.2
6.3
6.4
6.5
4.7.3
Paper Empty . . . . . . . . . . . .
4.7.4
Motor Control (Optional) . . . . . . .
Power Supplies . . . . . . . . . . . .
.. .
4.8.1 +5V Regulator (Schematic No. 63011143) .
4.8.2 +12V
and -12V Regulators (Schematic No. 63002308)
4.8.3 +35V Power Supply, Unregulated (Schematic No. 63002307).
SECTION 5
REMOVAL, REPLACEMENT AND ADJUSTMENT PROCEDURES
Introduction . . . . . . . . .
Mechanical Assemblies . . . .
5.2.1
5.2.2
5.2.3
5.2.4
5.2.5
5.2.6
5.2.7
5.2.8
5.2.9
5.2.10
5.2.11
5.2.12
5.2.13
Cover
(A). . . . . .
Carriage Mechanism (HA)
Driving Mechanism (HB) .
Spring Drum (HC) . . .
Damper (HD) . . . . . .
Frame
(HE). . . . . .
Paper Feed Mechanism (HF)
Pin
Feed Unit (HF) . . . .
Form
Feed Mechanism (HH)
Ribbon
Feed Mechanism (HI)
Electrical Hardware
(HJ). . .
Paper Stacker and Guide. .
Printer
Head and Associated Assemblies
SECTION 6
MAINTENANCE
Electrical Adjustments (model 101/101A)
Video
Amplifier Adjustment (Series 101)
Mechanical Adjustments . . .
Preventive Maintenance
(P .M.)
Recommended Tools .
Troubleshooting Guide . . .
SECTION 7
DRAWINGS
AND PARTS LISTS, ELECTRICAL
SECTION 8
DRAWINGS
AND PARTS LISTS, MECHANICAL
APPENDIX A
SIGNAL GLOSSARY
APPENDIX B
PARALLEL INTERFACE SPECIFICATIONS
ii
PAGE
·
4-31
· 4-31
· 4-35
. 4-35
4-37/4-38
4-37/4-38
5-1
5-1
· 5-1
5-2
5-5
.5-14
.5-14
.5-15
.5-19
.5-21
.5-24
.5-28
.5-34
.5-34
.5-35
6-1
6-1
6-1
6-2
6-3
6-4

LIST OF ILLUSTRATIONS
FIGURE
PAGE
. Modell 01 Printer (Front Cover Removed) .
1-1
1-2
1-3
1-4
1-5
1-6
1-7
1-8
1-9
2-1
4-1
4-2
4-3
4-4
4-5
4-6
4-7
4-8
4-9
4-10
4-11
4-12
4-13
4-14
4-15
4-16
4-17
4-18
4-19
4-20
4-21
4-22
4-23
4-24
4-25
4-26
4-27
4-28
4-29
4-30
5-1
5-2
5-3
5-4
1-2
5-5
5-6
5-7
5-8
5-9
5-10
5-11
5-12
5-13
5-14
Basic Block Diagram
Print
Head Components . . .
Printing the Letter (H)
Paper Movement Mechanism .
Left Front View of 101 Printer
Right
Front View of 101 Printer. .
Rear View of 101 Printer . . .. ....
Rear View (101 Electronics Cavity Removed) .
Printer Dimensions . . . . . . . . . .
Moder1
01 Functional Block Diagram. .
Functional
Flow Chart
Basic Timing Circuit
Prime Timing . . . .
Prime Circuit . . . . .
Select Circuit . . . .
Input Data Timing -No Busy Condition .
Data I nput Circuit . . .
Acknowledge Circuit . .
I
nput Data Causing Busy.
Busy Circuit . . . . .
Function Decoder . . .
Character Printing Block Diagram
·
1-3
· 1-4
· 1-4
1-4
1-8
· 1-8
1-9/1-10
. 1-9/1-10
·
2-1
· . 4-1
.... 4-2
· 4-3
· . 4-4
4-5
. . . . 4-7
· 4-8
4-9
·4-11
·4-12
..4-13
.4-15
·4-16
.4-17
Forward
and Reverse Clutch Drive Circuits.
Character Timing. . . . . . . . . .
Character Registration
and Timing Circuit
Normal
and Elongated Characters
. . . . . .4-19
Solenoid Positions, 1 through 7
Print
Head Timing . .
Power Driver Waveform
Line
Feed Circuit
Line
Feed Timing
Form
Feed and Vertical Tab Circuit
Form
Feed and Vertical Tab Timing
Bell Circuit . .
.. .... . . .
Paper Empty . . . . . . . . .
Location
of Motor Control Circuit . .
Motor Control Board Interconnection Diagram . .
Motor Control Timing. . . . . . . . .
Power Distribution Diagram . . . . . .
Model
101 Series Drive Train ~ . . . .
Main
Motor Drive and Belt Arrangements . . . .
Bushing End Play Adjustment
for Preload Clutch Shaft (HB-50)
Location
of Left Reed Switch (Top View) . . . . . . . . .
Bushing End-Play Adjustment
for Preload Clutch Shaft (HB-50)
Flexible Timing
Fence Mpunting, Series 101 . . . . . . . .
Fence Adjustment and Optic Housing. . . . . . . . . . . . .
Vertical
and Horizontal Alignment of single Channel Optics Housing. . .
Location
of Left Reed Switch (Top View) . . . .. . . . . . . . .
4-20
.4-21
.4-22
.4-22
.4-23
.4-25
.4-26
.4-27
.4-28
.4-30
.4-32
· .. 4-33
·
.. 4-33
·
.. 4-34
· . 4-36
· 5-5
·
5-7
· 5-11
· 5-12
· 5-13
· . 5-16
· 5-17
· 5-18
Removal
of Belt (32) Idler Slide (28), and Drive Pulley (26) . . . . . . . . .
Adjustment
for Paper Holder Gate . . . . . . . . . . . . . . .
· . 5-19
· 5-22
.5-23
.5-24
· 5-27
Maintaining
5/8 IN. (15.9 MM) Nominal Print Margin ....... .
Two Adjustment, Gear with stop Cam (H H-23) and Inside Cam (H H-14)
Ribbon
Feed Mechanism (Rear of Printer, Left Side) . . . . . . . .
iii
· .
5-31

LIST OF ILLUSTRATION (cont'd)
FIGURE
5-15 Backlash Adjustment, Bevel Gear (HI-43, 59)
5-16 Driving
SI ide Shaft A - Adjustment .
5-17 Ribbon Reversing Rod
Adjustment. . . .
5-18 Ribbon
Reverse Timing . . . . . . . . .
7-1 Schematic Diagram, Electronic Card No.1 (Sheet 1 of 3)
7-2 Schematic Diagram, Electronic
Card No.1 (Sheet 2 of 3)
7-3 Schematic Diagram, Electronic
Card No.1 (Sheet 3 of 3)
7-4 Schematic Diagram, Electronic Card
No.2 (Sheet 1 of 2)
7-5 Schematic Diagram, Electronic Card No.2 (Sheet 2 of 2)
7-6 Schematic Diagram, Power Driver Board (Sheet 1 of 2) .
7-7 Schematic Diagram, Power Driver Board (Sheet 2
of 2)
7-8 Schematic Diagram, Diagram, +5V Regulator . . . .
7-9 Schematic Diagram, ±12 V
Regulator. . . . . . .
7-10 Schematic Diagram, Video
Amplifier ....... .
7-11 Schematic Diagram, Elapsed Time Indicator (Optional)
7-12 Schematic Diagram, Multitap Transformer
50/60 Hz .
7-13 Schematic Diagram,
Motor Control. . . . . .
7-14 Wiring Diagram, Printer Mechanism. . . . . .
7-15 Interconnecting Diagram; Connector Board
7-16 Schematic Diagram,
LED Tape Reader (Optional)
7-17 Component Board Assembly, Electronic Card
No.1
7-18 Component Board Location, Electronic Card No.2
7-19 Component Board Assembly, +5 Volt Regulator.
7-20 Component Board Assembly, ±
12V Regulator
7-21 Component Board Assembly, Connector Board
7-22 Component Board Assembly, Power
Driver. . .
7-23 Component Board Assembly, Video
Amplifier
7-24 Component Board Assembly, Elapsed Time Indicator (Optional)
7-25 Electronic Cavity Assembly. . . .
7-26
W1 Harness Assembly . . . . . .
7-27
W2 Cable Assembly, Computer Input
7-28 W3 Power Cable Assembly . . . .
7-29 Component Board Assembly,
Motor Control (Optional) .
7-30
Harness Assembly, Motor Control .
8-1 Mechanical Subassemblies Series 101
8-2 Cover Assembly A . . . . . . .
8-3 Carriage Mechanism
HA . . . . .
8-4 Drive Mechanism
HB (Part 1) Series 101
8-5 Drive Mechanism (Preload Clutches), (Part 2) Series 101
8-6 Spring Drum HC
8-7 Damper HD. . . . . .
8-8 Frame
HE . . . . . .
8-9 Paper
Feed Mechanism HF
8-10 Pin Feed Mechanism (Left and Right) HG
8-11 Form Feed Mechanism HH . . . . . .
8-12 Ribbon
Feed Mechanism HI .....
8-13 Electrical Hardware HJ (No Illustration) .
8-14 Print
Head and Associated Assemblies. .
iv
PAGE
.5-31
.5-32
.5-33
.5-33
7-3
7-4
· 7-5
7-6
7-7
7-8
7-9
.7-10
· 7-11
.7-12
.7-13
.7-14
.7-15
· 7-16
·
.7-17
.7-18
· 7-19
· .7-21
.7-23
.7-25
.7-27
.7-29
· 7-31
.7-3:
.7-35
.7-37
.7-39
.7-41
.7-43
.7-45
8-3
8-5
8-7
8-9
·
8-11
.8-13
.8-15
.8-17
· .8-19
.8-21
.8-23
.8-25
.8-27
.8-28

SECTION 1
INTRODUCTION
This manual describes the Model 101 printer, manufactured by Centronics Data Computer
~orporation. It provides general information, detailed theory of operation and maintenance infor-
mation enabling field service personnel to service the printer. For serial input or other detailed
interface information, a separate document for each interface is published for your reference.
The manual is subdivided into eight sections, each with its specific purpose.
SECTION 1 -
SECTION 2-
SECTION 3-
SECTION 4-
SECTION 5-
SECTION 6-
SECTION 7-
SECTION 8-
INTRODUCTION, introduces the reader to the scope and content of the
mar'1ual, and provides the reader with a general description of the printer.
INSTALLATION, contains unpacking and installation instructions for the
printer.
OPERATION, describes the use of all operator controls and indicators.
THEORY OF OPERATION, contains a detailed description of each major
operation performed by the printer electronics, including flow charts, timing
diagrams and circuit diagrams.
REMOVAL, REPLACEMENT AND ADJUSTMENT PROCEDURES,
includes, step-by-step removal and replacement procedures of all major
assemblies and sub-assemblies in the printer.
MAl NTENANCE, includes electrical adjustments, preventive maintenance
procedures, and a troubleshooting guide.
ELECTRICAL DRAWINGS AND LIST OF MATERIALS, contains a com-
pleteset of schematic, wiring and component board layout diagrams and
their associated list of materials for the electrical portion of the printer.
MECHANICAL DRAWINGS AND PARTS LISTS, includes all printer as-
sembly drawings and their associated parts lists for the mechanical portion
of the printer.
APPENDICES - '(A) Signal Glossary
(8) Parallel Interface Specifications
1.1 GENERAL DESCRIPTION (FIGURE 1-1)
The Model 101 printer is a medium speed impact printer which uses a "5 x 7 dot matrix for
character generation.
The unit prints at a rate of 165 characters per second, which is approximately one full 132-
character line per second (including carriage return time). Paper is sprocket-fed, and paper widths
from 4 inches to 14-7/8 inches can be accommodated. The printer can produce one original and
four copies. Standard print format consists of 10 characters per inch horizontally and 6 lines per
inch vertically.
1-1 Rev.G

Figure 1-1. MODEL 101 PRINTER (FRONT COVER REMOVED)
1.2 LOGIC FLOW DIAGRAM (FIGURE 1-2)
The standard printer contains a 132-character buffer. For serial data inputs, optional serial
interfaces allow
data to be received at rates from 100 to 9600 baud. Several other optional inter-
faces
are available as required by the user ..
Once a line of printable characters is stored in the buffer, head motion is initiated by act-
ivating
the forward clutch, causing the print head to move from left to right across the paper. With
the head in motion, data is transmitted from the buffer to the character generator. From there,
character write pulses are sent to the driver circuits, which energize the print head solenoids causing
the print wires to form the characters on the paper.
Paper
movement is initiated by a line feed, vertical tab or form feed function. Vertical
forms movement is hardware - controlled by a vertical format unit (VFU) which controls vertical
spacing
by monitoring two channels in. .a punched paper tape.
In addition, the printer recognizes the following special control codes: bell, delete and
elongated character, as described in Section 1.3.3.
Rev.G
1-2

TIMING
FENCE
DA TA --r--...-t
INPUT
VFU TAPE
READER
A
OPERATOR ALARM
PANEL
CONTROL
1.
PRINT COMMAND
(CR OR LAST CHAR.)
2.
PAPER MOVEMENT
(LF, VT, FF)
3.
SPECIAL FUNCTIONS
(BELL, DELETE, EXP.
CHAR)
MEMORY
HEAD MOTION
CONTROL
PAPER MOTION
CONTROL
TIMING
WRITE
PULSES
Figure 1-2. BASIC BLOCK DIAGRAM
1.3 PRINTER OPERATION
CLUTCH
PAPER
MOVEMENT
SOLENOID
PRINT
HEAD
Basically, all printer functions can be grouped into one of the following three catagories:
1) character printing, 2) paper movement, and 3) other auxiliary functions such as bell, delete, etc.
1.3.1 CHARACTER PRINTING (FIGURE 1-3,1-4)
A small aluminum carriage supports the print head assembly .. During printing operation, the
carriage travels along the print line from left to right. Printing is accomplished by selectively firing
the print wires as the print head moves from left to. right across the print line. Printing impulses
energize the print solenoids and drive ·the print wir~s- against the ribbon, paper and platen
to form the characters in a dot matrix pattern. When the solenoids are de-energized, the wires are
withdrawn so they are flush with the surface of the jewel. Each solenoid .can fire independently
up to fives times for anyone character. Figure 1-3 shows an example of the dot matrix forming
the letter H. Character formations for the standard 64 ASCII set are shown in the Series 100
Operators Manual. Other available character sets are shown in Printer Character Sets brochure
(No. C332-20).
The print head (Figure 1-4) consists of the jewel, casting and seven solenoids with attached
print wires. The seven pr.int solenoids and their attached print Wires are arranged radially around
the print head. The free ends of the print wires pass through a wire guide at the front of the print
head, which properly spaces the wires so that the correct wires pass through the correct holes in the
print jewel.
Printing action is initiated when the input buffer has been filled or a carriage return (CR)
code has been received. The print head then sweeps across the page until a CR command is decoded
at the buffer output or the head reaches the 132-column limit switch. At this time, the print head
returns to the left margin and an automatic line feed is performed. As an option, the automatic
line feed can be disabled.
1-3
Rev. G