The First Stored-Program Computer(s)

• · Early 1940s, Mauchly and Eckert began to design the EDVAC - the Electronic Discreet Variable Computer.
• John von Neumann's influential report in June 1945:
• "The Report on the EDVAC"
• British scientists used this report and outpaced the Americans.
• Max Newman headed up the effort at Manchester University
• Where the Manchester Mark I went into operation in June 1948--becoming the first stored-program computer.
• Maurice Wilkes, a British scientist at Cambridge University, completed the EDSAC (Electronic Delay Storage Automatic Calculator) in 1949--two years before EDVAC was finished.
• Thus, EDSAC became the first stored-program computer in general use (i.e., not a prototype).

• The First General-Purpose Computer for Commercial Use: Universal Automatic Computer (UNIVAC).

3. ·
• Late 1940s, Eckert and Mauchly began the development of a computer called UNIVAC (Universal Automatic Computer)
• Remington Rand.
• First UNIVAC delivered to Census Bureau in 1951.
• But, a machine called LEO (Lyons Electronic Office) went into action a few months before UNIVAC and became the world's first commercial computer.

The Four Generations of Digital Computing.

· The First Generation (1951-1958).

1. Vacuum tubes as their main logic elements.
2. Punch cards to input and externally store data.
3. Rotating magnetic drums for internal storage of data and programs
• Programs written in
• Machine language
• Assembly language

Requires a compiler

· The Second Generation (1959-1963).

1. Vacuum tubes replaced by transistors as main logic element.
• AT&T's Bell Laboratories, in the 1940s
• Crystalline mineral materials called semiconductors could be used in the design of a device called a transistor
2. Magnetic tape and disks began to replace punched cards as external storage devices.
3. Magnetic cores (very small donut-shaped magnets that could be polarized in one of two directions to represent data) strung on wire within the computer became the primary internal storage technology.
• High-level programming languages

E.g., FORTRAN and COBOL

The Third Generation (1964-1979).

1. · Individual transistors were replaced by integrated circuits.

2. Magnetic tape and disks completely replace punch cards as external storage devices.

3. Magnetic core internal memories began to give way to a new form, metal oxide semiconductor (MOS) memory, which, like integrated circuits, used silicon-backed chips.

o Operating systems

o Advanced programming languages like BASIC developed.

· The Fourth Generation (1979- Present).

1. Large-scale and very large-scale integrated circuits (LSIs and VLSICs)
2. Microprocessors that contained memory, logic, and control circuits (an entire CPU = Central Processing Unit) on a single chip.
• Which allowed for home-use personal computers or PCs, like the Apple (II and Mac) and IBM PC.
• Apple II released to public in 1977, by Stephen Wozniak and Steven Jobs.
• Initially sold for $1,195 (without a monitor); had 16k RAM.
• First Apple Mac released in 1984.
• IBM PC introduced in 1981.
• Debuts with MS-DOS (Microsoft Disk Operating System)
• Fourth generation language software products
• E.g., Visicalc, Lotus 1-2-3, dBase, Microsoft Word, and many others.
• Graphical User Interfaces (GUI) for PCs arrive in early 1980s

MS Windows debuts in 1983, but is quite a clunker.

• Windows wouldn't take off until version 3 was released in 1990