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PDP-8 ASSEMBLER

IP.com Disclosure Number: IPCOM000128401D
Original Publication Date: 1967-Nov-01
Included in the Prior Art Database: 2005-Sep-15
Document File: 9 page(s) / 40K

Publishing Venue

Software Patent Institute

Related People

Powers, Michael: AUTHOR [+3]

Abstract

This report can be viewed as either an operating manual for the PDP-8 assembler or as a progress report on the Dexembler. The Dexembler is an assembler which hopefully will assemble PDP- 7, PDP-8, or PDP-9 programs, depending on which of several possible tables it reads. The PDP-8 assembler, BASS is a realization of this assembler, but one which is not fully parameterized. As described in this report, the PDP-8 Assembler produces only absolute code and assembles only for the PDP-8 (and PDP-4).

This text was extracted from a PDF file.
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THIS DOCUMENT IS AN APPROXIMATE REPRESENTATION OF THE ORIGINAL.

PDP-8 ASSEMBLER

Michael Powers

THE UNIVERSITY OF MICHIGAN Memorandum 12

CONCOMP: Research in Conversational Use of Computers ORA Project 07449 F.H. Westervelt, Director supported by: DEPARTMENT OF DEFENSE ADVANCED RESEARCH PROJECTS AGENCY WASHINGTON, DC CONTRACT NO. DA-49-083 OSA-3050 ARPA ORDER NO. 716 administered through: OFFICE OF RESEARCH ADMINISTRATION ANN ARBOR November 1967

PREFACE

This report can be viewed as either an operating manual for the PDP-8 assembler or as a progress report on the Dexembler. The Dexembler is an assembler which hopefully will assemble PDP- 7, PDP-8, or PDP-9 programs, depending on which of several possible tables it reads. The PDP-8 assembler, BASS is a realization of this assembler, but one which is not fully parameterized. As described in this report, the PDP-8 Assembler produces only absolute code and assembles only for the PDP-8 (and PDP-4).

Michael Powers 25 October 1967

TABLE OF CONTENTS

PREFACE.....iii
PDP-8ASSEMBLER.....1
I. INTRODUCTION.....1
II. ASSEMBLY PROCESSING.....1
III. BASS IN MTS.....3
IV. NAMES AND EXPRESSIONS.....4
V. INSTRUCTIONS AND PROCEDURE CALLS.....6
VI. DEBUGGING AIDS.....8
VII. OBJECT DECKS.....9
APPENDIX I.....11

I. INTRODUCTION

University of Michigan Page 1 Nov 01, 1967

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PDP-8 ASSEMBLER

The following sections describe the PDP-8 Assembler(8ASS), which is a collection of programs written mostly in FORTRAN IV (G) and operating under the Michigan Terminal System(MTS) on the IBM 360/67. BASS assembles programs for the Digital Equipment Corporation's (DEC) PDP-5 and PDP-8 computers. Once a program has been assembled, it may be punched on cards, saved in a file, or transmitted through the Data Concentrator over data lines. It is also possible to obtain binary paper tapes by use of the Data Concentrator.

The reader is assumed to be familiar with the reference manual for the PDP-8 available from DEC (Programmed Data Processor-8 User's Handbook, DIGITAL F-85, Digital Equipment Corporation, Maynard, Mass., 1964). For the description and use of assemblers in general the reader is referred to the description of the PAL-III assembler for the PDP-8 available from DEC (PAL-III Symbolic Assembler Programming Manual, DIGITAL 8/3/S, Digital Equipment Corporation, Maynard, Mass., 1965). BASS follows the PAL-III operation code and addressing conventions. The input format and program listing conventions of BASS are slightly different from those of PAL-III, however, since BASS is organized around a line format while PAL-III is organized around a paper tape format.

II. ASSEMBLY PROCESSING

An assembler is a vehicle for the transformation of symbolic source programs into the internal representation of machine instructions and data. Each PDP-8 machine instruction occupies exactly one location in its memory. The assembly language program is a sequence of input lines to the assembler which specifies these instructions in s...