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A Unified Approach to Microcomputer Software Development

IP.com Disclosure Number: IPCOM000131321D
Original Publication Date: 1978-Jun-01
Included in the Prior Art Database: 2005-Nov-10
Document File: 14 page(s) / 47K

Publishing Venue

Software Patent Institute

Related People

Tomlinson G. Rauscher: AUTHOR [+3]

Abstract

An ordered sequence of stages, well-supported development tools, good programming practices -- management backing brings it all together in microprocessor-based system development. The past several years have seen dramatic increases in the capabilities of microprocessors. Whereas five or six years ago there were only a few 4- and 8-bit processors with limited capabilities and slow speeds, today microprocessors range from 4 to 16 bits in word sizes, with bit-slice processors also available. These microprocessors have larger instruction sets, some with over 100 instructions, and fast instruction execution times, 1 to 2 microseconds for simple machine-language instructions. Another characteristic of more recent microprocessors is the increased address space, which may be 64 kilobytes or more. With this increased capability the microprocessors are able to perform larger and more complex functions, and thus more and more software is being written for the microprocessors to perform these applications. This means that software development for microprocessor-based products is no longer primarily a one-person job of just writing a small program; rather it is frequently a coordinated effort of several people working together to produce a complete, usable software product. Nevertheless, the unified approach to microcomputer software development is applicable to -- and should be used by -- projects involving one or several people.

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THIS DOCUMENT IS AN APPROXIMATE REPRESENTATION OF THE ORIGINAL.

This record contains textual material that is copyright ©; 1978 by the Institute of Electrical and Electronics Engineers, Inc. All rights reserved. Contact the IEEE Computer Society http://www.computer.org/ (714-821-8380) for copies of the complete work that was the source of this textual material and for all use beyond that as a record from the SPI Database.

A Unified Approach to Microcomputer Software Development

Tomlinson G. Rauscher

GTE Laboratories

An ordered sequence of stages, well-supported development tools, good programming practices -- management backing brings it all together in microprocessor-based system development.

The past several years have seen dramatic increases in the capabilities of microprocessors. Whereas five or six years ago there were only a few 4- and 8-bit processors with limited capabilities and slow speeds, today microprocessors range from 4 to 16 bits in word sizes, with bit-slice processors also available. These microprocessors have larger instruction sets, some with over 100 instructions, and fast instruction execution times, 1 to 2 microseconds for simple machine-language instructions.

Another characteristic of more recent microprocessors is the increased address space, which may be 64 kilobytes or more. With this increased capability the microprocessors are able to perform larger and more complex functions, and thus more and more software is being written for the microprocessors to perform these applications. This means that software development for microprocessor-based products is no longer primarily a one-person job of just writing a small program; rather it is frequently a coordinated effort of several people working together to produce a complete, usable software product. Nevertheless, the unified approach to microcomputer software development is applicable to -- and should be used by -- projects involving one or several people.

The magnitude of writing a significant piece of software for a microcomputer system can be roughly estimated from statistics given by Magers in this issue. At the typical rate of 10 instructions per person per day, one person can develop approximately 6 kilobytes of instructions in one year. A

software product comprising 32 kilobytes of instructions would require more than 5 man-years to develop. If the software is structured so that it can be broken down into five reasonable parts, it would take five people at least one year to complete. In applications where microprocessors are being used, however, one year for the development of software is an incredibly long time; products introduced at that rate might be obsolete by the time they were delivered. To develop the same 32kilobyte program in three months would ostensibly require 20 people. Due to problems of intercommunication, however, men and months are not interchangeable,' so that if 32 kilobytes of software are to be developed for a microcomputer i...