BA 103--Computers and Information Systems
List of Concepts

What happens when you start up your computer:
1. The processor finds instructions about the specific machine in ROM and checks that all the basic parts are in place. ROM is nonvolatile and information can only be changed by changing the chips.
2. CMOS memory is consulted to identify device addresses and types, such as how much memory, time and date, important information about secondary storage devices (e.g. the hard drive). Information in CMOS can be changed, but is maintained by a battery.
3. The boot drive is surveyed to find operating system software (DOS & BIOS). Resident parts of the operating sytem software are loaded into memory.
4. CONFIG.SYS and AUTOEXEC.BAT files are executed to install drivers for devices and define environmental setup factors. These are editable files on the boot disk.
5. The AUTOEXEC.BAT can be used to define a program(s) run at startup. For example, many computers are now set up to start WINDOWS right away

Terms and concepts you should know:

• Input, Processing, Output, & Storage. = IPOS
• Hardware, software, firmware (usually ROM).
• System software, "grass roots" software, programming languages, application packages
• Data, programs, utilities, drivers.
• MIS Directors, Programmers, Operators, End Users are all part of "the system"

Hardware
• System unit, devices, peripherals.
• Support devices=online or offline.
• System Unit=system (mother)board, processor, memory chips, slots, boards & ports
• Places along the BUS Route: processors, memory, expansion slots, ports, and boards.
• CPU = Registers, CPU = Arithmetic Logic Unit (ALU) and Control Unit.
• Intel CPU chips 8086, 8088, 80286, 80386, 80486, pentium
• Machine cycle synchronized by system clock. Hz=cycles per second. speed in MegaHertz (MHz) typical values: 233, 666, 2.24 GHz (Gigaherz)

Storage and transfer of information
• Serial vs. parallel transmission. width of the bus like lanes in highway: 8, 16, 32, 64 bit
• Primary (internal, memory) storage, secondary (external) storage.
• Memory: Primary storage for programs and data during processing. RAM, ROM, CMOS
• Memory (RAM) capacities such as 640K, 16 Meg, 24, 64,128,256,512... Megabytes of RAM
• Machine-readable media: hard disks, floppy disks, tape, Optical disks.
• Memory = primary (internal) storage of data and programs
• Registers in CPU for temporary storage: Instruction, Address, Storage, Accumulator.
• Computer does everything in machine language=binary code instructions. bits are on or off
• 00000000 to 11111111 represents 256 states (0 to 255 decimal) in 8 bits = a byte
• One byte is enough to represent a character, such as a letter, number, etc. in ASCII
• One Kilobyte = 1024 bytes, (640K is 655,360 bytes) one megabyte = 1024 kilobytes
• Database>File>Record>Field>Character=byte>bit
• (order of size) Bits bytes words kilobytes megabytes gigabytes terabytes
• Machine uses binary code=bits. Relate to 2-tick odometer for conversions to decimal.

• Hexadecimal (base 16) notation used by Assembly Language programmers. Relate to 16-tick odometer. 00 to FF represents 256 states (0 to 255 decimal) in two characters
• "Normal" People use decimal & character codes= ASCII & EBCDIC (7 or 8 bit)
• Error checking and parity bit set to give even number on, odd number on or none
• Milliseconds, microseconds, nanoseconds, picoseconds, femtoseconds

Media:
• Direct (Random) Access via addresses in the FAT vs. Sequential Access--tape
• floppy disks: 8.5", 5.25", 3.5" Single-sided, Double-sided, & High density (SS, DS, HD)
• ZIP drive is a 100MB floppy, cost about $100, $10 per disk, becoming standard
• Hard disks & Bernouli drives--generally slower than memory, faster than floppy & optical.
• Hard Drive capacities usually Gigabytes (GB) Gigabytes (Gigs, or GB). e.g.  30 GB, 60 GB; some typical older machines have Megabytes, such as 40, 230, 540, 850 MB. Since newer operating systems (Win95) are now more than 100 Meg, old machines don't make it anymore.
• CD-ROM & WORM, Magneto-Optical (M-O); Rewritable optical platters & Jukeboxes.
• typical CD-ROM is 650 MB
• CD-R and CD-RW, DVD-ROM, DVD recordable (several types)
• All this is changing rapidly as Optical becomes faster, cheaper and rewritable

Formats:
• Formatting disks sets up File Allocation Table (FAT), Sectors & tracks (sides).
• Hard drives have multiple disks (sides)--gives cylinders made up of corresponding tracks
• Partitioning Harddrive-makes one physical device look like more than one (logical) device.
• Root Directory & Subdirectories. Like branches on a tree, or filedrawers.
• DOS file names and types of files-- *.BAT, *.EXE, *.COM, *.TXT, *.DBF, *.TMP, *.WK1, Readme.doc.
• Wild cards *  (asterisk)  ?
• Autoexec.bat and Config.Sys are used on startup to configure the computer.

Hard drive Maintenance:
• Backup for CMOS startup data="Rescue Disk" (e.g.Norton Utilities)
• Chkdsk /f or Scandisk in DOS 6.x to fix lost allocation chains, check disk surface.
• Temporary files (*.TMP) can accumulate when applications terminate abnormally. clean them out.
• "Brush your teeth, wash behind your ears, and defrag your harddrive".

Input:
• Devices convert people-style information to machine usable formats.
• Keyboards--characters & function keys.
• Mice, trackballs, light pens & touch screens, digitizing pads, joysticks, yokes & pedals.
• Source Data Automation--barcode scanners, magnetic strip scanners, MICR (Magnetic Ink Character Recognition), optical image scanners (hand-held, flatbed), Optical Character Recognition (OCR)--e.g. Omnipage, TypeReader
• Voice input: IBM VOICETYPE (discreet speech), Dragon NaturallySpeaking and IBM ViaVoice(continuous)  See the MiniMBA pages for info and links on these. Good Speech recognition software now costs less than $150, but requires relatively heavy-duty machines (>233 MHz, >48 Meg RAM)

Output:
• Devices convert machine code to hardcopy, softcopy or info to other machines
• Display devices--Video--VDT, CRT, LCD--pixels and bit-mapped images.
• Video standards: Monochrome, CGA, EGA, VGA, s-VGA, XGA
• Teletypes, printers & plotters
• Impact--daisy wheel, ball, dot matrix: 9-pin and 24-pin ("letter-quality")
• Non-impact--thermal transfer, inkjet, laser. 300dpi vs. 600 (or more) dpi.
• High speed line printers and page printers.
• Color printers--inkjets most common. laser printers becoming more economical and common
• Voice output e.g. Arkenstone in Library scans books--> speech output
• Speech Recognition, IBM ViaVoice and Dragon Naturally Speaking

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