MARIE ISA

MARIE’s ISA contains thirteen instructions.

Hex	Binary	Instruction	Meaning
$0$	$0000$	JnS X	Jump and Store: Stores PC at address $X$ and jumps to $X+1$.
$1$	$0001$	Load X	Load contents of address X into ACC
$2$	$0010$	Store X	Store the contents of the ACC at address X
$3$	$0011$	Add X	Add the contents of address X to the ACC
$4$	$0100$	Subt X	Subtract the contents of address X from the ACC
$5$	$0101$	Input	Input a value from input device into the ACC
$6$	$0110$	Output	Output the value in the ACC to output device
$7$	$0111$	Halt	Terminate the program
$8$	$1000$	Skipcond C	Skip the next instruction on condition (C), if $C$ is: - $000$: Skips if $AC<0$ - $400$: Skips if $AC=0$ - $800$: Skips if $AC>0$
$9$	$1001$	Jump X	Load the value of X into PC
$A$	$1010$	Clear	Set the value of ACC to $0$.
$B$	$1011$	AddI X	Use the value at $X$ as the actual address of the data operand to add to ACC
$C$	$1100$	JumpI X	Uses the value at $X$ as the address to jump to
$D$	$1101$	LoadI X	Loads value from indirect address to ACC.
$E$	$1110$	StoreI X	Stores value in ACC at the indirect address.