TYPE OF OS.txt

TYPES OF OS-
1 Batch-punch cards/paper tape/magnetic tapes on which jobs were offline loaded
then we had to go to the system,those jobs were given to the operator,
operator will make batches of them,those batches one by one are given to the cpu
cpu will execute them ,in case the process asks for I/O then it sends it to its 
required problem until then the cpu will remain idle which means it wont do anything
else and will just wait for it to get I/O back and return which was a major problem 
(it was non premptive) and wont go to the next job until current job is finished
a lot of idle time builds up to complete all jobs which is annoying which can take
even days or months 
fortran was made to help a little while loading our jobs

2 multi programmed-it is non premptive which means if process p1 is in ram and is
taken to cpu ,cpu will execute it completely,until then other processes won't
do anything,here cpu wont sit idle ,its puts more importance of letting process
not stay idle

3 multi tasking-it is premptive,we have already decided that some procesees will
be executed for some time,if it dosent get completed in that certain time then
we will go to another process and save process one for sometime later,it gives more
emphasis on response time 

we use multitasking in our pc 

4 realtime-realtime means we are expected to not have time dealys and time matters
  two types HARD-time is very restricted like in missile system  SOFT-time can be a little delayed

            

5 distributed-means our processing environment is distributed all over the world 
or like our pc is all over the world and we can access them all and each one of them
have their own environment and have resources and also they are geographically
on diffferent places,in case one system faisl then work done can be through other
systems
6 clustered-same as distributed and are connected to the local network ,it has 
availability and fail tolerance 
7 embedded-only work on a fixed functionality,we cant do any changes to it,