EECS 1520 Lecture Notes - Lecture 1: Arpanet, Auxiliary Memory, David Boggs
DepartmentElectrical Engineering and Computer Science
Course CodeEECS 1520
: collection of physical elements making up machine
and related pieces: boxes, circuit boards, chips, wires, disk drives, keyboards
: collection of programs that provides instructions that
computer carries out.
Each later has specic role in design of system
Innermost: the way we represent information on the computer (managed by
binary digits of 1 and 0)
mental model that removes complex details
We can manage about 7 pieces of information in short-term memory at one
time called “Millers Law”
: instrument to record number values for basic arithmetic.
!: built and sold machines, which performed addition and
"#$%: built rst mechanical device to do
addition, subtraction, multiplication and division
&&': Jacquards loom, punched card. (First to make important
form of input)
: analytical engine, rst to include memory so that
intermediate values do not have to be re-entered.
: extended Babbage’s idea. “First programmer”. Series of loop
attributed to her.
#: produced and sold mechanical adding machine
(: developed rst electro-mechanical tabulator, which
read info from punched card. Later formed company called IBM.
)*: Turing Machine, laying foundation for major area of
$)+, were most famous machines of era in World War
&$-: consultant for ENIAC worked also for EDVAC.
UNIVAC I- rst computer to predict outcome of presidential election, also
Commercial computers built with vacuum tubes to store info
Primary memory device was magnetic drum rotating under read/write head
Input device: card reader that read holes punched in IBM card
Output device: either punched card or line printer
Storage device external to computer memory: auxiliary storage device.
(Magnetic tape was rst of these device)
Input device+output device+auxiliary storage= peripheral devices
Transistor ushered in second gen. of commercial computers, replaced
vacuum tube (smaller reliable, faster, durable and cheaper)
Also advent of immediate-access memory. Memory was made from magnetic
cores, each capable of storing one bit of info. Device was motionless,
accessed electronically, and info was available instantly.
Magnetic disk, new auxiliary storage device also developed in second
computer hardware generation. Magnetic disk faster than magnetic tape.
Also has own location identier called the address.
Second gen: transistors and other component of computer assembled by
hand on printed circuit board but in third, it is by integrated circuits.
Gordon Moore: cofounder of Intel. Moore’s law: number of circuit that could
be placed on single integrated circuit was doubling each year.
Transistors also used for memory construction
Auxiliary storage device still needed because transistor memory was volatile.
(When computer is o> info is gone)
Terminal= an input/output device with keyboard and screen.
Large-scale integration characterizes fourth generation.
Phrase personal Computer (PC) entered.
Stevel Wozniak and Steven Jobs created personal computer kit
IBM PC were soon followed by compatible machines
mid 1980s- big powerful machines created called “workstations”, these were
“networked” so there is interaction. Each computer designed to understand
set of instructions called machine language.
Computers using parallel architectures relied on set of interconnected central
Parallel machines organized so that processors all share same memory unit
Ethernet invented by Robert Metcalfe and David Boggs to connect machines
and sets of protocols to allow machines to communicate with one another
Novell Netware connected PC together with le server
Workstations or personal computers networked together=LAN
Internet descented from ARPANET
Internet used packet switching, way for message to share line
Internet made of di>erent networks across world communicating by using
common protocol, TCP/IP
SPSS: general purpose allocation program
Structured programming: logical disciplined approach to programming such
as Pascal and Modula-2
UNIX, PCDOS, MS-DOS: powerful operating system for standards for PC as
well as Macintosh
3 types of application package: spreadsheet, word processors and database
Lotus 1-2-3= successful spreadsheet, WordPerfect=rst word processor and
dBase IV: system that let user store, organize and retrieve data