LMC + addressing

Question 1

ADD xx

Answer 1

Add the number at location xx to the accumulator

Question 2

SUB xx

Answer 2

Subtract number at location xx from accumulator

Question 3

STA xx

Answer 3

Store the number in the accumulator in location xx

Question 4

LDA xx

Answer 4

load the number in location xx to the accumulator

Question 5

BRA xx

Answer 5

BRANCH: Jump the PC to the new memory location

Question 6

BRZ xx

Answer 6

Branch if the number in the accumulator is zero

Question 7

BRP xx

Answer 7

Branch if the number in the accumulator is positive

Question 8

INPUT

Answer 8

Move data from INPUT into the accumulator

Question 9

OUTPUT

Answer 9

Move data from the accumulator into OUTPUT

Question 10

HLT

Answer 10

HALT stop the program

Question 11

DAT xx is not a command what does it mean?

Answer 11

DAT tells you that the location is holding data not instructions

The programmer must make sure the program halts or jumps over any data

Question 12

Explain how named locations can be used in LMC programs

Answer 12

alternate to numbered memory locations

any location can be given a short name

the names can be used instead of location numbers in the program. this makes it easier to write.

Question 13

immediate addressing

Answer 13

the data itself

Question 14

direct addressing

Answer 14

memory location

Question 15

indirect addressing

Answer 15

location holds a pointer to somwhere else in RAM

Question 16

indexed addressing

Answer 16

an array reference