Little Man Computing

Little Man Computing is an instruction set for assembly language, composed of 12 instructions, using [[Memory Addressing#|#Direct]].

Example

Adding two numbers.

INP
STA NUM1
INP
ADD NUM1
OUT
 
NUM1 DAT 0

Labels

A label is a reference to a location within the RAM.

Defining

{label} OPCODE OPERAND

Referencing

The label is replaced with the location associated with the label in RAM.

OPCODE {label}

Instructions

Instruction	Name	Description
HLT	Halt	Stops the proogram.
ADD	Add	Adds the content of the memory address (operand) to the accumulator.
SUB	Subtract	Subtracts the content of the memory address (operand) to the accumulator.
LDA	Load	Loads the content of the memory address (operand) to the accumulator.
BRA	Branch	Branches to the memory address (operand).
BRZ	Branch if Zero	Branches to the memory address (operand) if the accumulator is zero.
BRP	Branch if Positive	Branches to the memory address (operand) if the accumulator is positive.
INP	Input	Takes an input as a number and stores it in the accumulator.
OUT	Output	Outputs the accumulator as a number.
OTC	Output as Character	Outputs the accumulator as an ASCII character.
DAT	Data	Indicates a location in memory to store data.