Changing the size of the cursor
Clearing the contents of the screen
Placing the cursor at an appropriate position on screen
Drawing any graphics shape on the screen
Receiving a key from the keyboard
Checking the memory size of the computer
Finding out the list of equipment attached to the computer
Formatting a floppy
Hiding a file from the directory
Displaying the directory of a disk
Sending the output to printer
Interacting with the mouse