University of Utah 1 CS Revisited Most universities used batch-oriented computing approach.

University

of Utah

11

CS Revisited

• Most universities used batch-oriented computing approach

University

of Utah

22

CS Revisited

• An ideal teaching environment:- Interactivity (time sharing)- Fast compilers?- or fast executables?

University

of Utah

33

BASIC

• “Beginner’s All-Purpose Symbolic Instruction Code”

• Created at Dartmouth University (1963) on GE mainframes

• Easy for non-CS people

University

of Utah

44

BASIC

• Extremely influential• (But not necessarily for teaching!)

- Adapted to minicomputers...- Then to personal computers...

University

of Utah

55

RSTS/11

• Operating System for PDP-11- “Resource Sharing Timesharing System”

• BASIC as user interface

University

of Utah

66

RSTS/11

• Used a filesystem!• Filesystems actually started with PDP-10,

popularized by PDP-11- one directory per user- 6.3 naming convention

University

of Utah

77

Demo

• BASIC on a PDP-11

University

of Utah

88

Personal Computer

• What makes a computer “personal”?• Two forces:

- interactivity- smaller, cheaper hardware

University

of Utah

99

Calculators

• First “personal” computing devices- Wang LOCI (1964)

http://www.oldcalculatormuseum.com/wangloci.html

University

of Utah

1010

Calculators

• First “personal” computing devices- HP-9100A (1968)- $5000

http://www.hpmuseum.org/hp9100.htm

University

of Utah

1111

Calculators

• Price wars!- Bowmar Brain $250 (1971)- Basic arithmetic- Used IC’s, not transistors

http://www.vintagecalculators.com/html/bowmar_calculators.html

University

of Utah

1212

Calculators

• Price wars!- HP-35 $400 (1972)- scientific calculator- RPN- goodbye, slide-rule!

http://www.hpmuseum.org/hp35.htm

University

of Utah

1313

Calculators

• HP-65 (1974)- $795- First programmable pocket calculator- Anyone have one?

http://www.hpmuseum.org/hp65.htm

University

of Utah

1414

Let’s reflect a bit...

• Minicomputers- Interactive but not “personal”

• Calculators- Interactive AND personal

but not general purpose- Programming “for the people”!

University

of Utah

1515

Moore’s Law

• Gordon Moore (co-founder of Intel)- 1964: observes that number of circuits per IC

doubles every year.

University

of Utah

1616

MOS

• Metal oxide semiconductor (MOS)- allows for greater chip density

• How about a computer-on-a-chip?

University

of Utah

1717

Intel 4004

• Began as a one-time project- Busicom and Intel- Build custom chips for a series of pocket

calculators

University

of Utah

1818

Intel 4004

• Ted Hoff (engineer at Intel)- assigned to Busicom project- Proposed general-purpose chips- Calculator logic implemented as software (in

ROM)

University

of Utah

1919

Intel 4004

• Ted Hoff (engineer at Intel)- assigned to Busicom project- Proposed general-purpose chips- Calculator logic implemented as software (in

ROM)• Brilliant!

University

of Utah

2020

Intel 4004

• Marketed in 1971• A complete set consisted of 4 chips

- CPU (4004)- I/O (4003)- RAM (4002)- ROM (4001)

University

of Utah

2121

Intel 4004

• 4-bit word length• 740 kHz clock speed

University

of Utah

2222

More microprocessors

• Intel 8008 (1972)- Similar story as 4004, only 8-bit

• Intel 8080 (1974)- Improved version of 8008- Priced at $360- Direct ancestor to x86 line!

University

of Utah

2323

Two forces at work

• Top-down- Time-sharing and interactivity

• Bottom-up- Personal calculators- Improvements in microchips

• When shall the twain meet?

University

of Utah

2424

Reminder

• Essay outline due Friday!

University

of Utah

2525

“Test Question”

• On a scrap of paper, write a question that encapsulates one of the points from today's class, and turn it in.

• (Put your name on it!)