1. 1 Chap. 1 Computers and Information ECE2030 Dr. John A. Copeland “Logic and Computer Design Fundamentals” 2nd Edition M. Morris Mano & Charles R. Kime http://www.ece.gatech.edu/academic/courses/ece2030/ http://www.csc.gatech.edu/copeland/jac/2030/

2. Signals Physical Types: Voltage Current Photons Fixed 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 (ECE4604) 2

3. 3 1-volt noise margin

4. A binary number is called a “Bit”. “0” or “1” Eight bits as a unit are called a “Byte”. “01101100” 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” 4

5. 5 Keyboard, mouse, CRT or LCD Display Floppy disk, hard drive, RAM (semiconductor IC), CD ROM Data and program instructions. FPU, MMU, Internal Cache.

6. 6 1x8 + 3 =11 base10 1x8 +0x4+1x2 +1 = 11 base10 If base > 10 new symbols must be defined for 11, 12,...

7. 7 Used in pocket calculators, reduces binary to decimal conversions.

8. 8 Alphanumeric characters assigned a 7-bit pattern or binary number. B 7 B 6 B 5 B 4 B 3 B 2 B 1 e.g., “A”= 1000001 Normally “Bytes” are expressed as B 7 B 6 B 5 B 4 B 3 B 2 B 1 B 0. The bits shown above would be 6-0, and B 7 is the “parity” or “high order” bit.

9. 9 Codes 0000000 (0) to 0011111 (31) End of Line: Teletype and DOS = LF+CR, UNIX = LF, Macintosh = CR CR (Carriage Return)LF (Line Feed) Tab, ^I LF, ^J CR, ^M