MARIE: Architecture Example: Lecture Notes

Here is MARIE's instruction set (each instruction has an opcode and up to $1$ operand:)

Opcode	Syntax	Description
0001	`LOAD X`	Loads the value at address `X` into the `AC`.
0010	`STORE X`	Stores the value in the `AC` into address `X` in memory.
0011	`ADD X`	Adds the value at address `X` to the `AC`.
0100	`SUBT X`	Subtracts the value at address `X` from the `AC`.
0101	`INPUT`	Takes input from the user and places it into the `AC`.
0110	`OUTPUT`	Outputs the value in the `AC` to the user.
0111	`HALT`	Stops the execution of the program.
1000	`SKIPCOND`	Skips the next instruction based on a condition in the `AC`.
1001	`JUMP X`	Sets the `PC` to `X`, causing the program to jump to the specified address.
1010	`JNS X`	Jumps to the instruction at address `X`.
1011	`JUMPI X`	Indirectly jumps to the address stored at address `X`.