Browse Prior Art Database

THE UNIVERSITY OF MICHIGAN Memorandum 20 AN ASSEMBLY LANGUAGE SYSTEM FOR DEC MINICOMPUTERS

IP.com Disclosure Number: IPCOM000128390D
Original Publication Date: 1969-May-01
Included in the Prior Art Database: 2005-Sep-15
Document File: 25 page(s) / 88K

Publishing Venue

Software Patent Institute

Related People

V. Michael Powers: AUTHOR [+5]

Abstract

A collection of programs, running in The University of Michigan Terminal System (MTS) on an IBM 360/67 computer system, accomplish assembly and linkage editing of relocatable programs written for DEC's PDP-1, PDP-5, PDP-8, PDP-7, and PDP-9. A link editor program can be used to merge the out puts from several different runs of the assembler and produce a single relocatable or absolute load module.

This text was extracted from a PDF file.
This is the abbreviated version, containing approximately 6% of the total text.

Page 1 of 25

THIS DOCUMENT IS AN APPROXIMATE REPRESENTATION OF THE ORIGINAL.

THE UNIVERSITY OF MICHIGAN Memorandum 20

AN ASSEMBLY LANGUAGE SYSTEM FOR DEC MINICOMPUTERS

V. Michael Powers

David L. Mills
Neal L. Laurance (Scientific Research Staff,
Ford Motor Company, Dearborn, Michigan)

CONCOMP: Research in Conversational Use of Computers

ORA Project 04449
F. H. Westervelt, Director

supported by:

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

CONTRACT NO. DA-49-083 OSA-3050

ARPA ORDER NO. 716

administered through:

OFFICE OF RESEARCH ADMINISTRATION ANN ARBOR May 1969

ABSTRACT

A collection of programs, running in The University of Michigan Terminal System (MTS) on an IBM 360/67 computer system, accomplish assembly and linkage editing of relocatable programs written for DEC's PDP-1, PDP-5, PDP-8, PDP-7, and PDP-9. A link editor program can be used to merge the out puts from several different runs of the assembler and produce a single relocatable or absolute load module.

PREFACE

This memorandum describes the PDP-5/8 and the PDP-7/9 language assemblers and the PDP- 8 Link- Editor/Loader which are currently running on the duplex IBM 360/67 system at the Computing Center of The University of Michigan under MTS (Michigan Terminal System). The programs are written in IBM System/360 OS Assembly Language, Level G. The memorandum serves both as a manual for the system user as well as a report on the system development.

Tim Swanson, of the Geophysics Laboratory, Institute of Science and Technology, effected the changes necessary to realize the PDP-1 version, and wrote the appendix.

V. Michael Powers

David L. Mills

University of Michigan Page 1 May 01, 1969

Page 2 of 25

THE UNIVERSITY OF MICHIGAN Memorandum 20 AN ASSEMBLY LANGUAGE SYSTEM FOR DEC MINICOMPUTERS

Neal L. Laurance

TABLE OF CONTENTS

PREFACE.....v
1. INTRODUCTION.....1
2. ASSEMBLING IN MTS..... 3
3. ASSEMBLY LANGUAGE.....5
3.1 Language Structure.....5
3.2 Fields.....6
3.3 Terms.....7
3.4 Expressions.....9
3.5 Relocatable Expressions.....14
4. DOCUMENTATION AND DEBUGGING AIDS.....16
5. PREDEFINED SYMBOLS.....22
5.1 Pseudo-ops.....23
5.2 PDP-8 Opcodes.....31
5.3 PDP-9 Opcodes.....34
6. RELOCATION.....36
6.1 Definitions and Methods.....36
6.2 Implementation: Logical Object Deck.....40
6.3 *8LINK: The Link Editor.....42
7. WRITING RELOCATABLE PROGRAMS.....49
8. OBJECT MODULE FORMAT.....53
REFERENCES.....57
APPENDIX: A VERSION OF THE ASSEMBLER FOR THE PDP- 1.....58

LIST OF TABLES

TABLE 1. Examples of Constant Conversion.....10
TABLE 2. Operators in Order of Decreasing Precedence.....11

[ Page x blank ]

[ Chapter ] 1. INTRODUCTION

Within the last few years, several assemblers have been developed at The University of Michigan to service the ever- increasing number of PDP-8s located on the campus1. These assemblers were designed to be run on a large machine and produce code which was executed

1 1. "PDP-8 Simulator System," University of Michigan Executive System for the IBM 7090 C...