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On early computers, every byte of data read or written was handled by the CPU (i.e., there was no DMA). What implications does this have for multiprogramming?
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Answer: 

The main reason for providing DMA is to give the CPU flexibility to perform any other task while the I/O is being performed by CPU. 

If there is no DMA in the multiprogramming system then the CPU will be fully occupied by the I/O devices, eventually leading no advantage of having a multiprogramming system benefit.

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Yeah. By the way, multiprogramming is still possible without DMA but it will be very slow because of I/O interrupts.

Read it more.

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Yes, right.
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1)The main thing is that the the I/O operations will be very slow.

2)In case if a data block is to be transferred to main memory , data block first gets transferred to cpu which then transfers the data to the main memory .This process is extremely slow and will increase the overall time  required by processes.

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