Computing - Little Man Computer


What does INP mean in LMC?


Input.

What does the INP instruction do in LMC?


Allow the user to input data.

Where is the input from INP stored in LMC?


In the accumulator.

What does STA mean in LMC?


Store address.

What is the instruction register for instruction 901 in LMC?


9.

What is the address register for instruction 901 in LMC?


01.

What does STA do in LMC?


Store the value in the accumulator at the given address.

What is the operand for STA?


The address.

What does ADD mean in LMC?


Add.

What does the ADD instruction do in LMC?


Add what is in the address given to the accumulator.

What does ADD 59 do in LMC?


Add what is in address 59 to the accumulator.

What does SUB mean in LMC?


Subtract.

What does the SUB instruction do in LMC?


Subtract what is in the address from the accumulator.

What does SUB 59 do in LMC?


Subtract what is in address 59 from the accumulator.

What does OUT mean in LMC?


Output.

What does OUT do in LMC?


Output/print what is in the accumulator.

What does HLT mean in LMC?


Halt/end.

What does HLT do in LMC?


Stops the execution of the program.

What does BRZ mean in LMC?


Branch if zero.

What does BRZ do in LMC?


If the contents of the accumulator is 0, set the program counter to the given address.

What does BRP mean in LMC?


Branch if positive/zero.

What does BRP do in LMC?


If the contents of the accumulator is 0 or positive, set the program counter to the given address.

What does BRA mean in LMC?


Branch always.

What does BRA do in LMC?


Set the contents of the accumulator to the given address.

What does DAT mean in LMC?


Data.

What does DAT do in LMC?


Instead of storing the instruction in RAM, store the operand given where that operation would be.

What is the program counter in LMC?


It holds the address of the next instruction the little man has to carry out.

What is direct addressing?


Where an operand is specified as a memory address holding the value to be used.

What is immediate addressing?


Where the operand is specified as the actual value explicitly.

Why is it called Little Man Computer?


Because it’s like a little man running about, grabbing instructions and doing all the operations in a computer.




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