Ch. 2 PPT Part 1 Flashcards
(31 cards)
What do we expect the OS to do?
Control/manage HW, run applications quickly
What are the objectives of the OS?
Convenience, efficiency, and the ability to evolve
Where does the OS sit in the grand scheme of things?
It sits between the hardware and the applications and APIs
What is a very important OS service?
The GUI. It makes everything more convenient
What features are more prevalent on Linux systems?
The ease at which developing is
Where does ISA come into the OS?
It’s how it interfaces with the hardware
What is ABI?
Application binary interface. It’s the means by which system calls are made and the program gains access to system resources
What does the OS do in terms of data?
It handles movement, storage, and processing of data
What is an example of an OS evolving?
The OS accommodating newer hardware or a security patch being released.
What OS is good with backwards compatibility?
Linux
How does the OS interact with the processor?
It relinquishes control and then depends on the processor to allow it to regain control
What was serial processing?
In the 1940’s and 50’s, users had control to the machine in series. Time would be wasted because you had no control over what someone did in there. Also, setup was long
What was the monitor?
It was an early kernel. Users would no longer have direct access to the CPU. The punched cards were put on a tape and run sequentially
How did the monitor output things?
The results were put onto an output tape and then printed out
What concept did the monitor introduce?
The interrupt, which was early multitasking
What other OS concepts did the monitor introduce?
Drivers, sequencing, and IO. Also, it was always sitting in memory and always running (resident monitor)
How did early hacking arise?
When the monitor was running a program, it had complete control.
How did you control use time with the monitor?
You could control the max time each person spent on there. When the cap was hit, there was an interrupt
What were the early modes?
User and system. It implemented early control over who could access what data. System calls were needed for hard drive access
What is JCL?
Job control language. Controls what compiler to use and what data to use
How does the monitor balance out?
It uses more memory but improves efficiency
What is multiprogramming?
The processor switches between jobs when it is waiting for IO or something
How do you calculate use time?
Multiply the percentage use by the time, then divide it by the total time.
What is a time-sharing system?
The idea of interactive jobs, where users are sitting behind a terminal and doing things
