IBM 1401:
A Legend Comes Back to Life: The Story Behind CHM's IBM 1401 Restoration_By Dag Spicer
Amid the sound of cards being punched and the smell of hydraulic fluid from its printer, a team of Museum volunteers is restoring a classic computer system from the past in one of CHM's Restoration Laboratories. Known as the IBM 1401, this computer was released in 1959 and became one of the most successful in IBM's history—indeed in the history of computing itself. Never heard of it? That is perhaps not surprising since it's 50 years old. At a time when the world was just beginning to see the potential of computers in education, business and government, the 1401 was already a home run for IBM. With this computer, the company rode the wave of modernization, rapid growth, and optimism about the future that was so characteristic of the early 1960s.
For nearly the entire twentieth century, IBM was well known in the business world. And, thanks to a corporate outlook that was attuned to its own public image, it was known to many ordinary Americans as well. IBM was conservative and staid. It was a company that sold service—not just machines. In a rapidly changing business world, IBM stood for reliability and was known for solving customer problems, not just selling them equipment.
IBM based its business—from its origins at the start of the twentieth century until the start of the electronic computer era—on a piece of stiff paper stock known as a “punched card.”
The punched card recorded information in the form of holes punched out of it according to a unique code. This information could be anything: someone's paycheck, a mathematical formula, a list of names, sales figures, or any information that could be contained in the punched card's 80-character limit. The idea of a card holding one type of information—a “unit” of information, if you will—led to the card being known as a unit record and the machines that processed these cards were known as unit record (or punched card) equipment.
Such punched card machines performed basic but powerful business functions such as sorting, collating, reproducing (making a copy of the card), and so on. IBM (and its competitors) built machines that could process this information according to a pattern set by the user using wires plugged into a control panel. Panels thus represent a set of instructions or basic form of program.
Unit record equipment was used for nearly the entire twentieth century, albeit in greatly declining numbers after about 1970. IBM made billions of dollars leasing equipment while American (and international) business adopted the unit record approach to their business processes. By one estimate, in 1960 the sale of blank punched cards alone represented nearly 30 percent of IBM's revenue.
IBM Moves to Electronics
IBM began its electronic computer efforts around the end of WWII. Most of these early computers were gigantic, room-filling mainframe machines with a limited market. Typical clients were the military, government departments and well-heeled corporations, insurance companies and banks. By the late 1950s, IBM had produced several successful computers—still large, to be sure—but with increasing performance and relatively decreasing cost, a theme that has come to characterize the industry. There were many incompatible systems and virtually no software tools or languages. (FORTRAN, the popular scientific and engineering programming language, would come out of IBM in 1957; the business-oriented language COBOL was announced in the early 1960s). Users—even competitors—banded together to share information and control panel-wiring patterns.
IBM's unique problem at this time was how to move their lucrative punched card business into the electronic stored program era. The stored program was a feature of mainframes but had not trickled down to the level of the small to medium-sized business user. The stored program concept evolved from a need to replace the control panel wiring so typical of unit record equipment to the infinitely more flexible system of storing instructions inside the computer (as we do today), rather than on punched cards or wiring panels.
The computer that allowed IBM to move its customers into the computer era was its Model 1401 Electronic Data Processing System. The 1401 is made up of three parts: a central processing unit (CPU), a card reader and punch (for reading and writing punched cards), and a high-speed printer. It also came with a magnetic tape drive—a feature that would revolutionize business.
The 1401 Arrives
The 1401 had a complex birth within IBM. One critical milestone in its creation was the decision to design a system that used magnetic core memory-like the RAM in today's computers—instead of the usual unit record equipment control panel that required laborious wiring. The result was a system that the user interacted with via a small number of special typed words. This was a big improvement in usability. In order to program a control panel, you needed considerable training and patience. While the 1401 did read and write punched cards, its optional magnetic tape system was a real breakthrough. Magnetic tape could store the equivalent of tens of thousands of punched cards on small, portable reels of tape. People began migrating their punched card information onto tape because it was not only more convenient, it saved space, time and, most of all, cost. IBM was pleasantly surprised (perhaps shocked) to receive 5,200 orders in just the first
five weeks—more than predicted for the entire life of the machine! The 1401 hit a sweet spot in the market. In fact, it hit two:
1. For users who already had very large systems, the 1401 could be used to offload many minor or “housekeeping” tasks like printing; and
2. For small and medium-size businesses, the 1401 was a replacement—one that worked at electronic speeds—for half a dozen separate pieces of punched card equipment.
As the post-war economic boom continued in the '50s and '60s, business expanded alongside. Many new businesses were formed in industry, commerce, manufacturing, and many other fields. They all needed a way to manage their work. The 1401 was developed to cost about the same as an equivalent separate unit record machines. But, it worked at electronic speeds and had no cumbersome control panel. In all, by the mid-1960s nearly half of all computer systems in the world were 1401-type systems.
Back to the CHM Restoration Lab
The Lab is a white room, about 40 feet by 30 feet simulating a data processing center from years past. An IBM clock hangs on the wall, a totem of IBM's varied manufacturing activities over the years and a tip of the hat to verisimilitude. You enter on a steep ramp built to accommodate a difference in floor height because the entire room is built on a raised floor beneath which snake the dozens of cables for the system. And there are cables! Each is the thickness of a junior-sized baseball bat, is thirty feet long, and weighs 20 lbs. or more. These information pipelines route the signals to and from the CPU to the card reader and punch, printer and tape drives. They have fearsome connectors at their ends that require real effort to plug in or disconnect. This is the Era of Big Iron and IBM was a giant in this industry. Its competitors were derisively known as “The Seven Dwarves.”
In the Lab are two complete 1401 systems. The first is from Germany; the second—from Connecticut—operated as late as 1995. Each machine has distinctive features but the restoration team settled on the latter system as its restoration target. As a visitor, you'll be invited to sit at a keypunch machine—a typewriter-like device that punches what you type onto a card. (The bits that are punched out are called “chad.”) Type your name and the key-punch whirs to life, clacking away as you type. It's an impressive feeling of power as your keystrokes are converted into punched cards.
A kindly restoration team member—most likely a former IBM customer engineer as are most of the team—takes your card and adds it to several others. He will feed all these cards into the card reader, then move to the CPU—a cabinet the size of two refrigerators—and push several buttons. Suddenly your cards are pulled into the card reader with a whoosh and flap-flap-flap sound. After a few moments this stops and the printer, a mechanical beast that can move 75 inches of a paper in single second, springs to life, printing your name in giant letters. You have just used a computer, 1960s style!
Getting a printout of your name is cool but don't be misled.
The 1401 was a serious business machine. It cranked out the payrolls and did the accounting for tens of thousands of businesses worldwide. The Museum is truly fortunate to have these machines. And getting one running was no small feat. It took a team of more than 30 active volunteers some 20,000 hours over five years and was truly a labor of love. Our 1401's each have over 500,000 separate parts, weigh four tons and—in their day—cost about $6,500 a month to lease (about $50,000 a month in today's dollars).
To Preserve and Present
Having an operating 1401 system is of great historical importance. It makes it possible to study these old applications and the way they were designed. A new generation can learn how people solved problems in the early days of computing and appreciate the creative solutions early computer pioneers found. Perhaps more importantly, in terms of IBM history and the industry as a whole, the 1401 was the product that gave IBM its first realistic glimpse of the size and importance of the market for computers. It caused a paradigm shift in how people worked with computers, whose capabilities (and limitations) would soon become the bedrock of our modern civilization.
