OS I/O Systems

cope with device speed mismatch

cope with device transfer size mismatch

maintain copy semantics

all of the mentioned

same as

not the same as

all of the mentioned

none of the mentioned

non maskable interrupts

blocked interrupts

maskable interrupts

none of the mentioned

Bus

I/O operation

Stream

Flow

holds a copy of the data

is fast memory

holds the only copy of the data

holds output for a device