PowerPoint PresentationSlide 2Slide 3Slide 4Slide 5Slide 6Slide 7Slide 8Slide 91Chap. 1Computers and InformationEE2030Dr. John A. Copeland“Logic and Computer Design Fundamentals”2nd EditionM. Morris Mano & Charles R. Kimehttp://www.ece.gatech.edu/academic/courses/ece2030/http://www.csc.gatech.edu/~copeland/2030/SignalsPhysical TypesVoltageCurrentPhotonsFixed Number of Discrete Levels (digital, not analog)2 levels - binary (simpler circuits for computers)Called (true, false), (high,low) or (0,1)multi-level - good for communications (EE4604)231-volt noise margin1-volt noise marginA binary number is called a “Bit”.Eight bits as a unit are called a “Byte”Bits may reside: on different memory elements in a semiconductor memory chip (C charged or not), on different spots on a magnetic disk (M + or -) on different spots on a CD (pit or no pit), on the input and outputs of “logic gates” in a computer “register” or “on a bus”45Keyboard, mouse,CRT or LCD DisplayFloppy disk, hard drive,RAM (semiconductor IC),CD ROMData and program instructions.FPU, MMU, Internal Cache.61x8 + 3 =13 base101x8 +0x4+1x3+1 = 11 base10If base > 10 newsymbols must bedefined for11, 12, ...7Used in pocket calculators, reduces binary to decimal conversions.8Alphanumeric characters assigned a 7-bit pattern or binary number.B7B6B5B4B3B2B1 e.g., “A”= 1000001Normally “Bytes” are expressed as B7B6B5B4B3B2B1B0. The bits shown above would be 6-0, and B7 is the “parity” or “high order” bit.9Codes 0000000 (0) to 0011111 (31)End of Line: Teletype and DOS = LF+CR, UNIX = LF, Macintosh = CRCR (Carriage Return)LF (Line Feed)Tab, ^ILF, ^JCR,
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