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THE UNIVERSITY OF MICHIGAN Memorandum 22 THE ELECTROWRITER AS A COMPUTER I/O DEVICE

IP.com Disclosure Number: IPCOM000128389D
Original Publication Date: 1969-Feb-01
Included in the Prior Art Database: 2005-Sep-15
Document File: 12 page(s) / 40K

Publishing Venue

Software Patent Institute

Related People

D. R. McCreery: AUTHOR [+5]

Abstract

This report describes the hardware used in the tests of the Victor Comptometer Corporation's Electrowriter as a computer input/output device. Tests were performed on a DEC PDP-9 computer equipped with an A-to-D converter and a D-to-A converter.

This text was extracted from a PDF file.
This is the abbreviated version, containing approximately 11% of the total text.

Page 1 of 12

THIS DOCUMENT IS AN APPROXIMATE REPRESENTATION OF THE ORIGINAL.

THE UNIVERSITY OF MICHIGAN Memorandum 22

THE ELECTROWRITER AS A COMPUTER I/O DEVICE

D. R. McCreery, H. W. Estry, F. G. Osterwisch (Also published as UM/RAO Report No. 69-4, Radio Astronomy Observatory, Department of Astronomy, The University of Michigan)

CONCOMP: Research in Conversational Use of Computers

F.H. Westervelt, Project Director
ORA Project 07449

supported by

ADVANCED RESEARCH PROJECTS AGENCY DEPARTMENT OF DEFENSE
WASHINGTON, D.C.

CONTRACT NO. DA-49-083 OSA-3050 ARPA ORDER NO. 716

administered through:

OFFICE OF RESEARCH ADMINISTRATION ANN ARBOR February 1969

ABSTRACT

This report describes the hardware used in the tests of the Victor Comptometer Corporation's Electrowriter as a computer input/output device. Tests were performed on a DEC PDP-9 computer equipped with an A-to-D converter and a D-to-A converter.

TABLE OF CONTENTS

1. INTRODUCTION.....1
2. BACKGROUND INFORMATION.....2
2.1 THE CONVENTIONAL ELECTROWRITER SYSTEM.....2
2.2 THE INTEREST IN NEW I/O DEVICES.....7
3. DESIGN OBJECTIVES.....8
4. DESIGN PROCEDURE.....10
4.1 SELECTION OF EQUIPMENT.....10
4.2 TESTS OF THE EQUIPMENT IN THE USUAL SYSTEM CONFIGURATION .....11
4.3 INTERFACE REQUIREMENTS.....12
4.3.1 Electrowriter to Computer.....12
4.3.2 Computer to Electrowriter.....14
4.4 ELECTROWRITER-TO-COMPUTER BREADBOARD TESTS.....14
4.5 COMPUTER-TO-ELECTROWRITER BREADBOARD TESTS.....15
5. PROTOTYPE OF AUXILIARY ELECTRONICS.....21
5.1 CONSTRUCTION.....21
5.2 CIRCUITRY.....21

University of Michigan Page 1 Feb 01, 1969

Page 2 of 12

THE UNIVERSITY OF MICHIGAN Memorandum 22 THE ELECTROWRITER AS A COMPUTER I/O DEVICE

5.2.1 Transformers and Power Supply.....25
5.2.2 Voltage Regulators, Card 1.....25
5.2.3 Pen Signal Generator, Card 2.....25
5.2.4 Voltage Controlled Oscillators, Cards 3 and 4.....28
5.2.5 Discriminators, Cards 5 and 6.....28
5.2.6 Pen Signal Detector, Card 7.....28
5.3 INSTALLATION.....28
6. CONCLUSIONS.....29
APPENDIX A. PHOTOGRAPHS OF CARDS.....32
APPENDIX B. VICTOR ELECTROWRITER DOCUMENTATION.....37

1.0 Specifications
2.0 Receiver Schematic
3.0 Transmitter Schematic

LIST OF FIGURES

Figure 1. Block Diagram of a Telephone Network.....4
2. The 601-A Data Set.....5
3. Electrowriter Model 25 Receiver and Electrowriter Model 21 Transmitter.....5
4. Auxilliary Electronics Interfacing the Electrowriter with the Digital Computer.....13
5. Diagram of Breadboard Tests of the Proposed Design.....16
6. Message Written at the Transmitter (top), Duplicated at Receiver(center), and Displayed on CRT (bottom).....17
7. Configuration of Breadboard Tests of Computer-to Electrowriter Auxiliary Electronics.....18
8. Device for Simulating the Computer.....19
9. Results of Breadboard Tests.....20
10. Two Views of the Construction of Auxiliary Electronics.....22
11. Circuit Diagram of Auxiliary Electronics.....23
12. Auxiliary Electronics Installed in PDP-9 Computer.....26
13. Cable Connections of Auxiliary Electronic...