What Happened Today, April 5th

Cuthbert Hurd is born. Hurd was a mathematician hired directly by IBM President Thomas Watson Sr. in early 1949 and was only the second IBM employee hired with a PhD at the time. A figure generally unknown to history, Hurd quietly encouraged IBM upper management to enter into the computer field, convincing them in the early 1950s that a market for scientific computers existed after a cross-country sales trip revealed pent-up demand. At the time, IBM enjoyed large profits from its traditional punch card accounting business so the change was difficult for IBM to make internally. Hurd's first great success was in selling 10 of IBM's 701 computers, its first commercial scientific machine, which rented for $18,000 a month. Shortly thereafter, he became manager of the IBM team that invented and developed the FORTRAN programming language under John Backus. Hurd died on May 22, 1996 in Portola Valley, California.

Cuthbert Hurd is born. Hurd was a mathematician hired directly by IBM President Thomas Watson Sr. in early 1949 and was only the second IBM employee hired with a PhD at the time. A figure generally unknown to history, Hurd quietly encouraged IBM upper management to enter into the computer field, convincing them in the early 1950s that a market for scientific computers existed after a cross-country sales trip revealed pent-up demand. At the time, IBM enjoyed large profits from its traditional punch card accounting business so the change was difficult for IBM to make internally. Hurd's first great success was in selling 10 of IBM's 701 computers, its first commercial scientific machine, which rented for $18,000 a month. Shortly thereafter, he became manager of the IBM team that invented and developed the FORTRAN programming language under John Backus. Hurd died on May 22, 1996 in Portola Valley, California.

Microsoft Corporation releases Windows 3.1, an operating system that provided IBM and IBM-compatible PCs with a graphical user interface (though Windows was not the first such interface for PCs). Retail price was $149.00. In replacing the previous DOS command line interface with its Windows system, however, Microsoft created a program similar to the Macintosh operating system, and was sued by Apple for copyright infringement. (Microsoft later prevailed in this suit).
Windows 3.1 added multimedia extensions allowing support for sound cards, MIDI, and CD Audio, Super VGA (800 x 600) monitors, and increased the speed of modem it would support to 9600 bps. It also finally abandoned "Real Mode," a vestigial environment dating back to the 8086 CPU. It provided scalable fonts and trapped the "three finger salute" (CTRL-ALT-DEL), prompting the user to avoid inadvertent re-boots. It also refined its OLE (Object Linking and embedding) concept, allowing users to cut and paste between applications.

IBM announces the release of its "System 360" mainframe computer architecture--embodied in five new models--launching its most successful computer system of all time. Called the "360" because it was meant to address all possible sizes and types of customer with one unified software-compatible architecture, the 360 family of machines generated in excess of $100 billion in revenue for IBM.
After five years of turbulent development, the Models 30, 40, 50, 60/62, and 70 were introduced along with 150 new supporting products, with IBM proudly claiming that software written for one model of System/360 could run on any other. This allowed customers to add or remove computing capacity without losing their investment in software. This had been a serious problem before the 360 with IBM alone having seven different, mutually-incompatible mainframe computer systems.
The 360 architecture was the basis for all subsequent mainframe architectures developed at IBM, as well as at IBM's many "plug-compatible" imitators. Its standardization of interfaces and methods allowed other companies to carve out a niche in the 360-dominated computer ecosystem. Throughout most of the 1960s, the System/360's success gave IBM a 65% market share, prompting observers to term the industry "Snow White (IBM) and the Seven Dwarfs." In 1965, the relative market shares were:

1. IBM: 65.3%
2. Sperry Rand (formerly Remington Rand): 12.1%
3. Control Data Corp.: 5.4%
4. Honeywell (formerly a division of Raytheon): 3.8%
5. Burroughs: 3.5%
6. General Electric: 3.4%
7. RCA: 2.9%
8. NCR (National Cash Register): 2.9%
9. The oft-forgotten eighth dwarf, Philco: 0.7%

On this day, Sun's Java team moves from Sun Microsystems to work in secret on its "Oak" development project (later re-named Java).

The contract is signed between the University of Pennsylvania’s Moore School of Electrical Engineering and the US Army to build the Electronic Numerical Integrator and Computer (ENIAC), a machine capable of the then-remarkable speed of 5,000 additions per second. ENIAC was shrouded in wartime secrecy since its main purpose was to compute "firing tables" for artillery shells. Before ENIAC, this was done by women (called "computers") working in large groups and using mechanical desktop calculators. ENIAC was not completed until after the war (February 1946) but a generation of computer designers learned from its design and from the summer course given by Eckert and Mauchly at the Moore School between July and August of that same year. ENIAC could solve a wide range of general purpose computing problems and was also used for classified military projects, including preliminary calculations for the US hydrogen bomb.

During preparations for the maiden voyage of the Columbia space shuttle, NASA engineers were monitoring a glitch in the shuttle’s computer systems. Synchronization between the main and backup AP-101 flight control computers was found to be the culprit behind the bug. Two gears were discovered to be out-of-sync – and repair would take at least a day to resolve the problem. Liftoff was re-scheduled for two days later, and countdown and launch on April 12 proceeded with no further setbacks. Columbia landed safely at Edwards Air Force Base in the Mojave Desert after orbiting Earth 34 times. NASA’s five space shuttles each housed 4 IBM AP-101 computers, with a fifth serving as a backup flight system computer. The AP-101s were built around transistor-transistor logic (TTL) semiconductor circuits and used the same architecture as the IBM System/360 family of computers. An earlier version of the AP-101 was first announced by IBM in 1966 as the 4Pi computer.

German computer pioneer Konrad Zuse files for a patent for the automatic execution of calculations, a process he invents while working on what would become the Z-1, Germany's first computer. In the patent application, Zuse offers the first discussion of programmable memory, using the term "combination memory" to describe breaking programs down into bit combinations for storage. This is the first device to calculate in binary with translation to decimal. Zuse goes on to build a series of computers.

The HP-41 calculator is used on board NASA's first space shuttle flight. The HP-41 allowed astronauts to calculate the exact angle at which they needed to re-enter the Earth's atmosphere.