Question

How would you go about creating a subroutine in MARIE assembly language that inputs text from a keyboard?

Answer 1

MARIE is basically abbrevated as Machine Architecture That Is Really Intuitive And Easy, It is a Assembly Language and Machine Architecture.

We have a bunch of registers in MARIE just like we have in other architectures and the registers are,

AC as in Accumulator: Data is stored in this register.

PC as in Program Counter: it stores current position of the instruction.

MAR as in Memory Access Register: stores or retrives the data.

MBR as in Memory Buffer Register and IR as in Instruction Register respectively.

Now, lf talking about Instructions MARIE has got a pretty number of them,The type of instructions are

Arithmetic

Data Transfer

I/O

Branch

Subroutine

Indirect Addressing

I/O:

This type contains INPUT and OUTPUT instructions respectively,

INPUT instruction takes the input from the keyboard as stores in AC

OUTPUT instruction takes the data from AC and displays it.