Robert Garner and Frederick (Rick) Dill The development of the most popular computer of the 1960s and the story of its restoration at age 50. he IBM 1401 Data lying technologies, we begin with its passing decks of cards with holes Processing System vacuum tube forebears. We cover punched in them through various was the world’s IBM’s development of the 1401’s electromechanical “unit record” ma- T most popular com- basic enabling technologies and chines. These machines sorted and puter during much trace its origins in business account- merged cards, did simple calculations, of the 1960s. Announced in 1959, it ing machines. We highlight its key punched cards, and printed reports. was one of IBM’s earliest transistor- features and characteristics, its mar- Most machines were controlled by ized computers. The IBM 1401 tran- ket succession, and even its appear- hand-wired plug boards tailored for sitioned thousands of businesses ance in popular culture. We also particular jobs. By the 1950s, IBM’s and institutions to stored-program describe the volunteer project at the operations from the leasing of unit computing, and its tape- and disk- Computer History Museum in Moun- record machines and the sale of bil- oriented systems freed users from tain View, California, that success- lions of punched cards each year the decades-long practice of storing fully restored two tape-oriented were very profitable. data on punched cards. In 1965, half 1401 systems to full operation. By this time, calculators with of all computers were IBM 1401s punched cards for input and output or members of its family. Figure 1 Early Accounting Machines, were being used to augment account- shows a tape-oriented 1401 system Calculators, and ing machines. Announced in 1948, from the 1960s. Stored-Program Computers the IBM 604 Electronic Calculating In this overview of the develop- For the first six decades of the 20th Punch was about the size of two ment of the IBM 1401 and its under- century, many businesses processed refrigerators. It was a vacuum tube, data for inventory, billing, receiv- plugboard-controlled, serial-decimal- Digital Object Identifier 10.1109/MSSC.2009.935295 ables, and payroll by repetitively digit machine with 50 digits of 28 WINTER 2010 IEEE SOLID-STATE CIRCUITS MAGAZINE 1943-0582/10/$26.00©2010IEEE Authorized licensed use limited to: KnowledgeGate from IBM Market Insights. Downloaded on February 5, 2010 at 15:10 from IEEE Xplore. Restrictions apply. FIGURE 1: A tape-oriented IBM 1401 Data Processing System from the early 1960s. From left to right: 1402 Card Read Punch, 729 Magnetic Tape Unit, 1407 Console Inquiry Station, 1401 Processing Unit, 1403 Printer. (Image courtesy of IBM Archives.) storage that could multiply and rency) [2]. It was a stored-program (about US$180,000 to US$300,000 divide. In 1949, IBM also offered the computer with instructions and data today), versus only US$2,000 to Card-Programmed Calculator (CPC), residing in 2,000 words on a mag- US$2,500 per month for a set of unit a product that interconnected an IBM netic drum rotating at 12,500 r/min. record machines, such as a 604 Cal- 604 wired for common subroutines, By 1956, a dozen commercial firms culating Punch (US$650 per month), an extra storage unit, and the popu- had delivered about 1,000 stored- a 407 Accounting Machine (US$1,000 lar IBM 402 Accounting Machine [1]. program computers and 3,200 calcu- per month), a sorter, a collator, and About 4,500 IBM 604s and 130 CPCs lators, with IBM and the Univac so on [2], [3]. were installed [2]. division of Sperry Rand leading the Particularly during the 1950s, com - In 1951, UNIVAC pioneered the marketplace [2]. puter design was closely interwoven business stored-program computer. Broadly speaking, stored-program with rapidly evolving circuit tech- Soon thereafter, IBM and other com- computers were considerably more nologies and techniques. The 1950s puter manufacturers introduced com- flexible and adaptable than plug- vacuum tube computers—about puters for the business and scientific board-based accounting ma chines. 3,600 were installed commercially marketplaces. The IBM 650 Magnetic Their software was easier to load, [2]—were typically based on diode Drum Data Processing Machine an- maintain, and distribute than wiring logic circuits with vacuum tube res- nounced in 1953 was the first widely and handling plugboards. However, toration of logic levels. Stored-pro- popular, low-cost business and scien- large-scale stored-program com- gram memories employed mercury tific computer. The 650 was installed puters were too expensive for all but electroacoustic delay lines (UNIVAC at more than a thousand customer the largest corporations. Typical I), electrostatic Williams cathode- sites and rented for about US$4,000 monthly rentals ranged from ray tubes (IBM 701 and 702), or other per month (US$32,000 in today’s cur- US$25,000 to US$40,000 per month approaches. Vacuum tubes suffered IEEE SOLID-STATE CIRCUITS MAGAZINE WINTER 2010 29 Authorized licensed use limited to: KnowledgeGate from IBM Market Insights. Downloaded on February 5, 2010 at 15:10 from IEEE Xplore. Restrictions apply. from high heat dissipation and fila- transistors were far superior to point- quently grew into a working proto- ment burnout from thermal cycling, contact devices for digital logic cir- type of a fully transistorized 604, parameter drift, secondary emission, cuits because of their higher current publicly revealed in October 1954 and dust-induced cathode-to-grid gain, greater fan-out, and orders-of- and demonstrated in several U.S. shorts. Storage CRTs suffered from magnitude lower collector cutoff cur- cities [1], [6]. Based on this effort, internal particle contamination and rent. Even though alloy-junction was IBM’s 608 Transistor Calculator prod- proved difficult to manufacture. Vacuum slower and more temperature-sensi- uct was announced in April 1955, tube machines of this era were typically tive than point-contact, he advocated and it became the world’s first fully serviced several times per week. IBM for alloy-junction’s higher reliability transistorized commercial calcula- went so far as to establish a small in- and predictability, lower manufac- tor when delivered in December 1957 house pilot line to demonstrate reli- turing cost, and greater circuit ver- [1]. Nevertheless, only 32 units were able production of vacuum tubes satility [6]. produced, as it became outmoded by for computing machines [1]. For In 1953, Logue conducted a class other IBM products [4], [11]. Figure 2 main memory, concerted efforts by in transistor digital circuit design. shows a photo of a transistorized 604 printed-circuit card. In place of the IBM 604’s 1,400 Businesses and institutions throughout twin-triode tubes, the transistorized the world used the IBM 1401 in the 1960s version used 2,200 alloy-junction germanium transistors; it occupied to process rapidly growing amounts of half the volume and consumed 95% information. less power than the original. Even its power supplies and neon tube in- dicator drivers were solid-state, the IBM, MIT, and others made magnetic For lab assignments, six IBM vacuum first time all functions of a large core the technology of choice due to tube machines were reconfigured to electronic calculating machine were its high reliability and fast access use transistors. One of the projects implemented with transistors [1]. times. By 1956, IBM had automated was a cross section of the IBM 604 Its direct-coupled transistor and di- the production of its core memory calculator. The design project subse- ode-transistor logic ran at a 50-kHz planes [4]. cycle rate with 5-V signal swings [7]. To access its magnetic core memory, Early IBM Transistor Development three parallel transistors were and Manufacturing needed to drive a core half-select Bell Labs invented the transistor in line [4]. 1947 and broadly disclosed the tech- Although the transistorized 604 nology in the summer of 1951. It was very reliable, one issue with early continued to focus on the point-con- alloy-junction transistors was that tact germanium transistor, as did base resistance was too high for digital IBM’s initial transistor investiga- circuits. Logue attempted to convince tions. Although no one knew how to transistor vendors—GE, Raytheon, manufacture point-contact transis- RCA, and Westinghouse—to lower tors reliably with repeatable stable base resistance, but the effort was to characteristics and reasonable gain, no avail since their transistors met the their faster speed over junction needs of the more popular communi- transistors was attractive to com- cation applications. puter designers [1]. Also, due to a In 1954, a Poughkeepsie research negative resistance region at higher team (working in the site’s defunct emitter currents, a bistable latch pickle factory) began to design tran- could be implemented with just a sistors for use in future calculators single point-contact transistor in - and computers. To lower the transis- stead of a cross-coupled pair of tor’s base resistance, they used a transistors [5]. FIGURE 2: A printed-circuit logic card disk-shaped base with a ring contact In 1952, Joseph Logue joined IBM’s with germanium diodes and alloy-junc- around its circular periphery. The nascent transistor research group in tion transistors from the 1955 experimen- emitter was alloyed on one side of tal transistorized 604 calculator—basis of Poughkeepsie, New York, after trou- the IBM 608, world’s first fully transistor- the disk and a larger collector on the bleshooting IBM 701 storage tubes. ized commercial calculator. (Photograph other, allowing for some misalign- He concluded that alloy-junction courtesy of Robert Garner.) ment (see Figure 3). 30 WINTER 2010 IEEE SOLID-STATE CIRCUITS MAGAZINE Authorized licensed use limited to: KnowledgeGate from IBM Market Insights.