IRS Brings Up 6000-Terminal Multiuser Unix System

from the April 15, 1985 issue of ComputerWorld magazine

by Bryan Wilkins

It has taken four years to implement, but an AT&T Unix-based distributed processing system is now being used by a branch of the Internal Revenue Service in its 10 offices.

The project began in 1981 — before distributed processing in a multiuser environment was a popular concept — when IRS planners opted to implement such a system in 10 IRS branch offices. sa Ae

By 1983, a contract was awarded for the installation of 400 minicomputer systems that would support dumb Ascii terminals and would run under both Digital Research, Inc.’s CP/M and AT&T Unix operating systems software. These specifications were spelled out, to the consternation of vendors, by IRS planners.

A year and a half later, 400 Zilog, Inc. Model 31 systems have been installed, more than 6,000 terminals are hooked up, and Eugene Barbato Jr., chief of the IRS’ Consulting Services branch, is a happy man.

Barbato’s shop has a healthy library of more than 2,000 AT&T Unix applications programs. Most important of all, the headaches common to incompatible systems installation that the federal government often suffers as a result of contracting laws have been few.

No alternatives to multiuser system

“In 1981, we decided there were no alternatives to a multiuser system, since we knew we could not become locked into one vendor’s solution,” Barbato commented last week at an AT&T Unix users meeting held at the IRS’ main headquarters. “The other vendors’ products were dead in the water as far as meeting our requirements. They couldn’t because they did not have [an AT&T Unix] capability, and Zilog did.”

The Zilog machines are used across the country at district and branch offices of the IRS, where they support administrative jobs such as tracking correspondence and the examinations of delinquent taxpayers, the collection of payments, the resolution of problems, inventory controls such as the tracking of liens placed on delinquent taxpayers’ property and word processing.

Barbato’s shop serves as a clearinghouse, or a broker testing Unix applications products developed by vendors or at universities.

One AT&T Unix application product, the Multi-Channel Memo Distribution Facility, was developed at the University of Delaware for the U.S. Army and modified to fit the IRS offices. It delivers mail to addresses on the IRS’s 400 systems automatically through designated routes lodged in the memory of the system.

To Barbato, one of the main advantages of the Unix environment is the ability to control local processing rather than using a centralized management system. Yet this advantage has led to the major problem now facing the system — the inability to perform micro-to-mainframe processing.

“We can download but can’t upload [data]. This capability was not built into our requirements when we ordered the current system, and privacy regulations dictate that we can’t access the main data processing centers [where taxpayer returns are processed for errors and delinquencies}, much as we would like to,” Barbato said. He added that the agency is currently working on uploading processed data from the Zilogs to a stand-alone front-end processor that will check the data for accuracy prior to mainframe entry.

The IRS’ AT&T Unix system is currently using a data base management system developed by Informix Corp. in which the requirements for applications development are clear-cut. “We are trying to proscribe the use of C, except on a waiver basis, when writing applications,” Barbato said. He justified this move on the grounds that programmers at government salary scales who are proficient in C programming are snapped up by private-sector “Beltway Bandits,” firms in the Washington, D.C., area that pay wages four times higher than what the IRS pays. “We would just get lines of code no one could later make sense of,” he said. re

Experiments order of the day

Other developments at Consulting Services, where experiments are the order of the day, are the variety of terminals hooked up to the Zilogs, such as Apple Computer, Inc.’s Lisa and Macintosh, Texas Instruments, Inc.’s Professional workstation and the IBM Personal Computer. Additionally, Zilogs are being linked in clusters at large district offices, where processing needs are greater, by private branch exchanges acting as data traffic cops.

Barbato spoke wryly of the current fascination in the marketplace with local-area networks.“You may really need a local-area network when your users really need the power of the personal computer; otherwise, what’s wrong with distributed processing?”

Despite this demurral, Consulting Services does have a local-area network that is used for applications deyelopment. Comparing the mini-terminal emulation approach with the network-micro approach, Barbato said the costs are equal.