university of utah 1 fortran assignment due tonight @ 7:30pm questions?
TRANSCRIPT
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of Utah
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Early 1960's Mainframe Companies
• Snow White (IBM)• Seven Dwarfs
- Control Data, Honeywell, Philco, Burroughs, RCA, GE, NCR
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of Utah
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IBM in 1961
• 7090/7094- large scientific mainframe
• 1401- small mainframe
• 7070- “business” version of 7090
• 1620- another small mainframe
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of Utah
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IBM in 1961
• 7090/7094- large scientific mainframe
• 1401- small mainframe
• 7070- “business” version of 7090
• 1620- another small mainframe
ALL
INCOMPAT
IBLE!
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of Utah
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SPREAD
• Committee at IBM (1961)- Current machines not scalable- What to do about it?
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of Utah
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The Answer
• One unified product line- for business AND science
• “Bet the company”
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of Utah
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System/360
• A family of related machines- 25:1 performance ratio
• All binary-compatible with each other!!!- Same executables run on each model of 360
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of Utah
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How?
• Microprogramming- Same instruction set- But implemented differently for each
machine!
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of Utah
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Lasting trends
• System/360 used 8-bit “bytes”• 32-bit word length• General-purpose registers
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of Utah
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EBCDIC
• “Extended Binary Coded Decimal Interchange Code”
• Two standards- ASCII for minicomputers- EBCDIC for mainframes
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of Utah
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Emulators
• 360 included emulation modes for- 7000-series- 1401
• Customers could migrate existing applications- Sorry, Honeywell!
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of Utah
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Famous People
• Gene Amdahl- “Amdahl's Law”- Principle designer of System/360
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of Utah
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Famous People
• Fred Brooks- “The Mythical Man-Month”
Based on experiences writing OS/360
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of Utah
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Summary
• System/360- extremely successful!- first “line” of computers- established many current conventions
• Direct ancestor of IBM's current mainframes!