University

of Utah

11

Altair 8800

• How to make it usable?- Peripherals- Programming language

University

of Utah

22

Altair 8800

• How to make it usable?- Peripherals- Programming language- Disk storage and OS

University

of Utah

33

DOS ??

• Not MS-DOS (yet)• Mainframe DOS vs microcomputer DOS

- multi-user vs single-user- multi-tasking vs single-tasking- roomful of peripherals vs few peripherals

University

of Utah

44

CP/M

• “Control Program for Micros”• De facto OS for microcomputers in late

1970s / early 1980s

University

of Utah

55

CP/M

• “Control Program for Micros”• De facto OS for microcomputers in late

1970s / early 1980s• But where did it come from?

University

of Utah

66

• Contractor for Intel• PL/I cross compiler for 8080 chip

- PL/M

Gary Kildall

University

of Utah

77

• Developed simple disk controller as a side-project (CP/M)

• Intel didn’t want it...

Gary Kildall

University

of Utah

88

Digital Research

• Founded by Gary Kildall and wife Dorothy McEwen (1976)- originally “Intergalactic Digital Research”

• CP/M as main product- < $100

University

of Utah

99

Porting blues

• Many 8080-based systems out there• CP/M had to be ported to each!

- A hassle• Along comes IMSAI (1977)

University

of Utah

1010

Porting blues

• Refactored CP/M- larger part was cross-platform- smaller part was platform-specific

• Now only small part had to be rewritten for each new platform!

University

of Utah

1111

Porting blues

• Refactored CP/M- larger part was cross-platform- smaller part was platform-specific

• Now only small part had to be rewritten for each new platform!

• BIOS- “Basic Input / Output System”

University

of Utah

1212

IMSAI 8080

• “Clone” of Altair 8800

http://www.imsai.net/Movies/WarGames.htm

University

of Utah

1313

IMSAI 8080

• The WarGames computer!

http://www.imsai.net/Movies/WarGames.htm

University

of Utah

1414

CP/M Demo

University

of Utah

1515

Meanwhile...

• Microcomputer revolution takes place in mid-1970s

• What were the “big” computer companies doing?

University

of Utah

1616

DEC

• Big and faster• VAX-11 (1977)

- follow-up to PDP-11

http://en.wikipedia.org/wiki/Image:Vax11-780.jpg

University

of Utah

1717

VAX

• Technical specifications- 32-bit address space- virtual memory- 16 general purpose registers- million instructions per second

University

of Utah

1818

VAX

• Classic “CISC” architecture- 250 instructions- Try to do as much as possible in hardware!

example: POLY instruction

University

of Utah

1919

VAX

• Plural: “vaxen”• $120,000• Approx. 100,000 sold in 1970’s - 1980’s

University

of Utah

2020

VAX

• Operating Systems- VMS- UNIX

Internet nodes

University

of Utah

2121

VAX

• Operating Systems- VMS- UNIX

Internet nodes• Software outlives hardware!

University

of Utah

2222

VT-100

• Terminal for VAX machines (1978)• 80x24 text display• ASCII

http://vt100.net/vt_history

University

of Utah

2323

IBM

• What was IBM doing in 1970’s?- continuing System/370 line- minicomputers (System/38)- experimental “personal” computers

University

of Utah

2424

IBM

• What was IBM doing in 1970’s?- continuing System/370 line- minicomputers (System/38)- experimental “personal” computers- Oh, and hiring lawyers...!

U.S. vs. IBM (1969 - 1981)

University

of Utah

2525

DEC and IBM

• Missed the microcomputer bandwagon• DEC

- sells architecture, not computers- “corporate jewels”

• IBM- distracted by other concerns

University

of Utah

2626

Reminder

• Midterm on Friday!• One sheet of notes

University

of Utah

2727

“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!)