Answer:
Memory-mapped I/O and port-mapped I/O are two complementary methods of performing input/output between the central processing unit and peripheral devices in a computer. An alternative approach is using dedicated I/O processors, commonly known as channels on mainframe computers, which execute their own instructions.
Answer:
Answered below
Explanation:
//Program is written in Python programming language
def charCnt( fileName, char){
if not fileName.exists( ):
return sys.exit(1)
else:
openFile = open("$fileName.txt", "r")
readFile = openFile.read( )
fileLength = len (readFile)
count = 0
for character in range(fileLength):
if readFile[character] == char:
count++
openFile.close( )
return count
}