Little Man Computer (LMC) Editor
You can use this simple Little Man Computer (LMC) editor below to check any LMC code you have written to ensure it outputs correctly.
Use the reminders on the right for the 11 commands needed in the OCR A-Level specification. LMC is a simplified form of assembly language.
This page is under active development.
INP is used without a label to input a number. The number is temporarily stored in the accumulator. Example: INP
OUT will output the current value of the accumulator. Example: OUT
STA stores the value that is currently in the accumulator into a named memory location. Example: STA num1
ADD is used to add the value of a named memory location to the value currently stored in the accumulator. Example: ADD num1
SUB takes away the value of a named memory location from the value currently stored in the accumulator. Example: SUB num1
LDA is used to load the value of a stored variable into the accumulator.
Example: LDA num1
BRZ is used to branch to a labelled line of code if the value in the accumulator is exactly 0. Example: BRZ ifzero
BRP is used to branch if the value in the accumulator is currently positive (including 0). Example: BRP repeat
BRA is used to branch regardless of the accumulator's current value. Example: BRA loop
HLT will stop the program. Example: HLT
DAT defines and stores data in memory. It creates a variable or memory location that can hold a specific value. It is written after the final HLT command. Example: fifty DAT 50