IS revision

IS revision

1. Proprietary vs open source

   • open source
     • refers to software that is available for anyone to access or change the code
   • proprietary
     • refers to software that is owned by the individual or company who published it

2. Switch VS Router

   • Switch
     • network switch can connect multiple devices and networks to expand the LAN
   • Router
     • a router will allow you to share a single IP address among multiple network devices

3. Von Neumann Architecture

   • program counter (PC)
     • holds the memory address of the next instruction to be fetched from primary storage
   • memory address register (MAR)
     • holds the address of the current instruction that is to be fetched from memory, or the address in memory to which data is to be transferred
   • memory data register (MDR)
     • holds the contents found at the address held in the MAR, or data which is to be transferred to primary storage
   • current instruction register (CIR)
     • holds the instruction that is currently being decoded and executed
   • accumulator (ACC)
     • it is a special purpose register and is used by the arithmetic logic unit (ALU) to hold the data being processed and the results of calculations

4. Trace Tables

   • tests if a piece of code is working correctly
   • tests for logic errors
   • Columns usually have variables in them
     • however sometimes they could have any information a programmer is interested in

5. system software

   • Software that controls the computer system
     • examples
       • windows
       • MAC
     • advantages
       • Their single greatest bit of leeway is that they meet exact necessities of the client
       • With presentation of master frameworks, information recently bound to a few people are frequently appropriated and made accessible
     • disadvantages
       • Some software that are designed specifically for a certain business, may not be compatible with other general software
       • Application software that is used commonly by many people, and then shared online, carries a very real threat of infection by computer virus or other malicious programs