Pos

An economical electronic

point-of-sale updating system

by DAVID G. HAMMEL

Raytheon Company

Bedford, Massachusetts

INTRODUCTION

A major trend in the business world is toward more

complete record keeping of business performance. The

demands of government (federal, state and municipal)

are ever increasing for purposes of tax evaluations. In

addition, business executives are interested in obtaining

more complete information, within the shortest delay

period, pertaining to their company's financial operations.

For the past half century one of the basic tools used

in businesses to record transaction data is the cash

register. Throughout these years, the cash register has

kept pace with the times, offering improved features to

meet the business demands. However, this mechanical

device has serious inherent limitations in its totalling

and counting capabilities and its means of communicating

with data processing systems.

To meet the increasing demands of business, pointof-

sale systems are being designed electronically. The

organization and performance of one of these systems,

termed the Transaction Data System, is the subject of

this paper. A summary of the system's main features is

as follows:

1. The system can service a large number of clerk-operated

stations and special monitor stations while

maintaining an acceptable message cyclic rate.

2. The system can perform all of the functions associated

with cash registers, but in much greater detail.

3. The system can store and update large amounts of

business information for inventory purposes.

4. The system can provide management with continuous

access to any and all of the accumulated business

data without interrupting other system functions.

5. The system can function as a satellite to a general

purpose computer. Such a polymorphic organization,

according to Project MAC reports, 1 for one, is cost

effective.

The system achieves economy because it is designed

specifically for point-of-sale applications, incorporating

a low cost cyclic memory storage device and other

saving features.

Systems concept

A powerful attribute of electronic computing equipment

is the ability to execute arithmetic operations at

microsecond speeds. This is at least four orders of

magnitude faster than the average business application

demands of a cash register. Effective use of this

computing speed calls for one central processor to

handle the work of all the transaction stations in the

organization. The system described herein, designated

the Transaction Data System, is organized in this way.

The Transaction Data System is comprised of a

central processor termed the Transaction Central, a

number of operator stations termed Transaction Stations,

and a special Monitor Station as shown in the

block diagram of Figure 1. In business application, the

Transaction Station provides the input-output functions

associated with the cash register. It enters transaction

data into the system, prints out an itemized customer's

sales receipt, operates the cash drawers, and if desired,

displays transaction data to both the customer and

operator.

The Monitor Station is used by management to

request printout of any data stored in the Transaction

Central, allowing business activities and sales figures to

be scrutinized at all times without interrupting the other

system functions. The Transaction Central receives and

processes all station messages, performing the arithmetic

and storage functions common to the cash register,

but in much greater detail. In addition, it can provide

complete or partial inventory control according to the

business requirements.

This system is unique in that its data processing

capabilities are limited to updating operations. This

restricted performance in no way conflicts with the

system objectives, though it does negate the processing

of versatile stored programs, as may be required to

maintain customer accounts. Its purpose is to afford an

economical