A good answer might be:

Yes. Programs and data are both in main memory when they are active.


Example of Machine Language

Let us say that an electric toothbrush has a processor and main memory. The processor can rotate the bristles left and right, and can check the on/off switch. The machine instructions are one byte long, and correspond to the following machine operations:

Machine InstructionMachine Operation
0000 0000Stop
0000 0001Rotate bristles left
0000 0010Rotate bristles right
0000 0100Go back to start of program
0000 1000Skip next instruction if switch is off

Here is the main memory for the toothbrush system:

AddressMachine Instruction
0 
1 
2 
3 
4 

The toothbrush is wired so that when the switch is turned on, the instructions are performed one at a time, in order, starting at address zero. The program can be re-started at address zero with the instruction 0000 0100. The toothbrush is supposed to rotate the bristles left and right while the switch is on, and stop when the switch is off.


QUESTION 4:

Fill in main memory starting at address 0 with the machine instructions to control the toothbrush. (Please take the time to do this. If you do, you will be able to tell people that the first program you ever wrote was for an electric toothbrush. You do not want to pass up this opportunity).