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081124slides_handouts - 1 UVa CS205 Engineering Software...

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Unformatted text preview: 1 UVa CS205 Engineering Software 081124 Programming Lore UVa CS205 Engineering Software 081124 Punch Card Programming Keypunch Machines Card duplicators JCL Magnetic tapes Batch Processing Birth of CS night owls CS Department museum: http://www.cs.virginia.edu/brochure/museum.html UVa CS205 Engineering Software 081124 First Computer at UVa UVa CS205 Engineering Software 081124 Computer Memory 2 GB (16 Gbit = 16,000,000,000 bits) DDR2 SODIMM 2 UVa CS205 Engineering Software 081124 0.00 1.00 2.00 3.00 4.00 5.00 6.00 7.00 8.00 9.00 10.00 11.00 12.00 13.00 14.00 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003 2006 Computer Memory Cost Cost per bit 1971: 13.02083333 cents/per bit 1979: 0.30517578 cents/per bit 2007: 0.00000059 cents/per bit 2008: 0.00000025 cents/per bit Constant $ Constant $ 0.00000000 0.05000000 0.10000000 0.15000000 0.20000000 0.25000000 0.30000000 0.35000000 1 9 7 9 1 9 8 1 1 9 8 3 1 9 8 5 1 9 8 7 1 9 8 9 1 9 9 1 1 9 9 3 1 9 9 5 1 9 9 7 1 9 9 9 2 1 2 3 2 5 2 7 UVa CS205 Engineering Software 081124 Computing Trends in General ¡ CPU speeds ¢ Moore’s Law: doubling every 18 months (tapering) ¡ CPU density (currently 45 nm –Dunnington 6-core/Hi-K ) ¢ 32nm technology for SRAM recently announced. ¡ CPU device count ¢ Similar trends (currently ~ 1.0 billion transistors, 1.9 billion coming next year) ¡ Secondary storage costs ¢ Similar trends (currently ~$125 for 1 TeraByte, $200 last year) Unparalleled Advances! E x p o n e n t i a l UVa CS205 Engineering Software 081124 Paying to Use Memory ¡ Fred Brooks, Mythical Man Month, 1975: Program Space as Cost: How big is it? Aside from running time, the space occupied by a program is a principal cost. This is true even for proprietary programs, where the user pays the author a fee that is essentially a share of the development cost. Consider the IBM APL interactive software system. It rents for $400 per month and ,when used, takes at least 160 K bytes of memory. On a Model 165, memory rents for about $12 per kilobyte per month. [this was in 1975 $] If the program is available full-time, one pays $400 software rent and $1920 memory rent for using the program..... One frequently hears horror expressed that a 2 M byte machine may have 400 K devoted to its operating system...400 K devoted to its operating system....
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This note was uploaded on 04/05/2010 for the course CS 150 taught by Professor Humphreys,g during the Spring '08 term at UVA.

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081124slides_handouts - 1 UVa CS205 Engineering Software...

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