Browse Prior Art Database

I/O EXTENSIONS TO RAMP

IP.com Disclosure Number: IPCOM000128402D
Original Publication Date: 1967-Oct-01
Included in the Prior Art Database: 2005-Sep-15
Document File: 12 page(s) / 45K

Publishing Venue

Software Patent Institute

Related People

Mills, David: AUTHOR [+3]

Abstract

RAMP is a multiprogramming system written for the PDP-8 and designed primarily for real-time interactive systems using a variety of I/O devices. The structure of the basic system nucleus is described in Reference 1. This memorandum describes the system interface to I/O device support routines and the conventions under which they operate. Several different kinds of I/O devices have been attached to PDP- 8/RAMP systems, and support routines for these devices have been coded. Some of these are described herein.

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Page 1 of 12

THIS DOCUMENT IS AN APPROXIMATE REPRESENTATION OF THE ORIGINAL.

I/O EXTENSIONS TO RAMP

THE UNIVERSITY OF MICHIGAN Memorandum 11 David Mills

CONCOMP: Research in Conversational Use of Computers ORA Project 07449 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 October 1967

TABLE OF CONTENTS

LIST OF FIGURES.....v
I. INTRODUCTION.....1
II.BASIC SYSTEM ARCHITECTURE.....1
2.1 The Task.....2
2.2 Real-Time and Task-Time Operations.....3

III. I/O DEVICE SUPPORT ARCHITECTURE.....4
3.1 Record Formatting.....6
3.2 Device Allocation.....7
3.3 Message Processing.....8
3.4 Device Support Routine Interaction.....15
3.5 Store-and-Forward Operations.....19
3.6 Error Recovery.....28

IV. TIMING AND LOADING CONSIDERATIONS.....29
REFERENCE.....32

LIST OF FIGURES

1 Data Byte Format.....5
2 DCB Table Entry.....9

University of Michigan Page 1 Oct 01, 1967

Page 2 of 12

I/O EXTENSIONS TO RAMP

3 Dispatcher Task.....11
4 Command Language Interpreter.....13
5 Copy Task.....14
6 Read/Write Tasks.....16
7 Input/Output Tasks Segment Returns.....17
8 Typical Read Segment.....20
9 Typical Input Device Interrupt Routine.....22
10 Typical Write Segment.....23
11 Typical Output Device Interrupt Routine.....25
12 Store-and-Forward Processing.....26

[ Chapter ] I. INTRODUCTION

RAMP is a multiprogramming system written for the PDP-8 and designed primarily for real-time interactive systems using a variety of I/O devices. The structure of the basic system nucleus is described in Reference 1. This memorandum describes the system interface to I/O device support routines and the conventions under which they operate. Several different kinds of I/O devices have been attached to PDP- 8/RAMP systems, and support routines for these devices have been coded. Some of these are described herein.

Since the publication of Reference 1, several functional improvements have been incorporated into the currently operating PDP-8/RAMP systems. In particular, the copy nucleus has been completely rewritten and is described below. The command language interpreter has also been restructured so that hangups can occur only in those pathological cases where device support routines malfunction. In addition, the I/O utility routine package has been expanded to include routines for reading and printing decimal integers. These latter functional improvements do not directly affect the utility of the RAMP system in its multiprogramming environment and are not discussed extensively in this memorandum.

[ Chapter ] II. BASIC SYSTEM ARCHITECTURE

The basic architecture of the RAMP system is discussed in depth in Reference 1 and is only briefly summarized here. The basic system nucleus consists of a task-switching monitor, an interrupt identifier, a set of buffer management routines, a rudimentary command language interpreter, and...